Restaura l'antialiasing de fcos al port Metal de cube_lines

CLAUDE.md

@@ -4,7 +4,16 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 ## Project Overview
 
-This is a cross-platform Shadertoy-like fragment shader viewer built with SDL3 + OpenGL 3.3. The application loads and displays GLSL shaders from the `shaders/` directory with runtime switching capabilities.
+This is a cross-platform Shadertoy-like fragment shader viewer built with SDL3. It supports two rendering backends:
+- **SDL3 GPU** (default): renders via Vulkan on Linux/Windows and Metal on macOS.
+- **OpenGL 3.3** (fallback): the original backend, used automatically if SDL3 GPU init fails.
+
+Selection at launch:
+```bash
+./shadertoy --backend=gpu     # force SDL3 GPU
+./shadertoy --backend=opengl  # force OpenGL
+./shadertoy --backend=auto    # default: GPU first, fall back to OpenGL on failure
+```
 
 ## Build and Development Commands
 
@@ -30,13 +39,21 @@ make macos_debug
 make linux_debug
 ```
 
+### Compiling Shaders to SPIR-V
+The SDL3 GPU backend reads compiled SPIR-V (`.frag.spv`) at runtime. Run this after touching any `.vk.glsl` file:
+```bash
+cmake --build build --target compile_shaders
+```
+Requires `glslc` (Debian/Ubuntu: `apt install glslang-tools`; macOS: `brew install glslang`).
+
 ### Running the Application
 ```bash
-./shadertoy [SHADER_PATH] [-F|--fullscreen]
+./shadertoy [SHADER_NAME_OR_PATH] [-F|--fullscreen] [--backend=auto|gpu|opengl]
 
 # Examples:
-./shadertoy shaders/test.frag.glsl
+./shadertoy test                            # auto backend, shaders/test/
-./shadertoy -F shaders/fractal_pyramid.frag.glsl
+./shadertoy --backend=gpu seascape          # force SDL3 GPU (Vulkan/Metal)
+./shadertoy -F shaders/fractal_pyramid      # explicit folder path, fullscreen
 ```
 
 **Runtime Controls:**
@@ -46,28 +63,49 @@ make linux_debug
 
 ## Architecture
 
-### Core Design
+### Layered design
-All application logic resides in `src/main.cpp` (~469 lines) - a monolithic design that's straightforward to understand. Key components:
+- `src/main.cpp` — SDL3 window, event loop, shader-list scanning, dispatch to a backend.
+- `src/rendering/shader_backend.hpp` — abstract `IShaderBackend` interface + `ShaderMetadata` / `ShaderUniforms` / `ShaderProgramSpec` shared types. Two factories: `makeOpenGLBackend()`, `makeSdl3GpuBackend()`.
+- `src/rendering/opengl_shader_backend.{hpp,cpp}` — OpenGL 3.3 implementation. Loads `<folder>/<name>.gl.glsl` at runtime.
+- `src/rendering/sdl3gpu/sdl3gpu_shader_backend.{hpp,cpp}` — SDL3 GPU implementation. Loads `<folder>/<name>.frag.spv` (Linux/Windows) or `<folder>/<name>.frag.msl` (macOS); shares one passthrough vertex shader from `shaders/_common/passthrough.vert.{spv,msl}`.
+- `src/rendering/sdl3gpu/shader_factory.hpp` — small helper that loads a shader binary/source from disk and creates an `SDL_GPUShader`.
 
-1. **Shader Loading System** - Automatic directory scanning of `.glsl` files, sorted alphabetically
+### Shader folder layout
-2. **OpenGL Rendering** - Single fullscreen quad with fragment shader using GL_TRIANGLE_STRIP
+One folder per shader, under `shaders/`:
-3. **Event Loop** - SDL3-based with vsync (SDL_GL_SwapWindow + 1ms delay)
+```
-4. **Resource Path Resolution** - Multi-path fallback system for executable, relative, and macOS bundle paths
+shaders/<name>/
+    <name>.gl.glsl    # OpenGL GLSL 3.30 (handwritten)
+    <name>.vk.glsl    # Vulkan GLSL 4.50 (handwritten)
+    <name>.frag.msl   # Metal Shading Language (handwritten)
+    <name>.frag.spv   # generated by `make compile_shaders` from .vk.glsl
+    meta.txt          # Name / Author / iChannelN
+shaders/_common/
+    passthrough.vk.glsl    # shared fullscreen-triangle vertex (Vulkan)
+    passthrough.vert.spv   # generated
+    passthrough.vert.msl   # handwritten Metal
+```
+Folders starting with `_` or `.` are skipped by the scanner. The `meta.txt` parser is in `Rendering::parseMetaFile`.
+
+### Backend selection logic (`main.cpp`)
+1. Parse `--backend=...` flag (default `auto`).
+2. If not OpenGL: create a window with no flags, instantiate `Sdl3GpuShaderBackend`. If `init()` fails AND choice was `auto`, destroy the window and continue. If choice was `gpu`, exit with error.
+3. Otherwise: create a window with `SDL_WINDOW_OPENGL` and instantiate `OpenGLShaderBackend`.
 
 ### Global State (main.cpp)
 ```cpp
-shader_list_           // Vector of discovered .glsl shader paths
+shader_list_           // Vector<ShaderEntry { folder, base_name }>
 current_shader_index_  // Active shader in rotation
-current_program_       // OpenGL shader program handle
 shader_start_ticks_    // Base time for iTime uniform calculation
 window_                // SDL3 window pointer
-shaders_directory_     // Shader directory path (resolved at startup)
+backend_               // unique_ptr<IShaderBackend>
+shaders_directory_     // Shaders root path (resolved at startup)
 ```
 
 ### Dependencies
-- **SDL3** - Window/input management, OpenGL context
+- **SDL3** ≥ 3.2 — windowing, events, GPU API (`SDL_gpu.h`)
-- **GLAD** - OpenGL 3.3 loader (statically linked via `third_party/glad/`)
+- **GLAD** — OpenGL 3.3 loader (used only by the OpenGL backend, statically linked via `third_party/glad/`)
-- **C++17 stdlib** - filesystem, fstream, vector, algorithms
+- **C++17 stdlib** — filesystem, fstream, vector, algorithms
+- Build-time tool: `glslc` (only required to regenerate `.frag.spv`)
 
 ### Platform-Specific Code
 Uses preprocessor defines (`WINDOWS_BUILD`, `MACOS_BUILD`, `LINUX_BUILD`) for:
@@ -77,6 +115,22 @@ Uses preprocessor defines (`WINDOWS_BUILD`, `MACOS_BUILD`, `LINUX_BUILD`) for:
 
 ## Shader System
 
+### Authoring a shader (manual steps)
+For each new shader, three handwritten files live in `shaders/<name>/`:
+1. **`<name>.gl.glsl`** — OpenGL GLSL 3.30 (the original Shadertoy-style format described below).
+2. **`<name>.vk.glsl`** — Vulkan GLSL 4.50 with explicit `layout(set=3, binding=0) uniform ShadertoyUBO { float iTime; vec2 iResolution; } u;` and `layout(set=2, binding=N) uniform sampler2D` for any texture channel.
+3. **`<name>.frag.msl`** — Metal Shading Language. Entry point must be named `<name>_fs`. Uniforms come in via `[[buffer(0)]]`; samplers via `[[texture(N)]] [[sampler(N)]]`.
+
+After editing any `.vk.glsl`, rebuild SPIR-V: `cmake --build build --target compile_shaders`.
+
+The MSL is **not** auto-generated — write it by hand following the same convention as `aee_2026/source/core/rendering/sdl3gpu/msl/*.msl.h`.
+
+### Shadertoy → Vulkan/Metal porting cheatsheet
+- `iResolution` is `vec2` here (no `.xy`). Reconstruct vec3 manually if needed.
+- Replace `texture(iChannel0, ...)` calls — no texture channels currently wired through the GPU backend (planned).
+- The shared vertex stage emits `vUV` already in Shadertoy convention `(0,0)` bottom-left → `(1,1)` top-right; multiply by `iResolution` to get `fragCoord`.
+- The Y axis is flipped in NDC inside the shared vertex shader so Vulkan/Metal render right-side-up like OpenGL.
+
 ### Shader Format (GLSL 3.3 Core)
 All shaders must follow this structure:
 

CMakeLists.txt

@@ -17,6 +17,9 @@ set(OpenGL_GL_PREFERENCE GLVND)
 # --- LISTA EXPLÍCITA DE FUENTES ---
 set(APP_SOURCES
     src/main.cpp
+    src/rendering/shader_backend.cpp
+    src/rendering/opengl_shader_backend.cpp
+    src/rendering/sdl3gpu/sdl3gpu_shader_backend.cpp
 )
 
 # Fuentes de librerías de terceros
@@ -29,6 +32,21 @@ set(EXTERNAL_SOURCES
 find_package(SDL3 REQUIRED CONFIG REQUIRED COMPONENTS SDL3)
 message(STATUS "SDL3 encontrado: ${SDL3_INCLUDE_DIRS}")
 
+# --- COMPILACIÓN DE SHADERS (Vulkan SPIR-V) ---
+find_program(GLSLC_EXE NAMES glslc)
+if(GLSLC_EXE)
+    message(STATUS "glslc encontrado: ${GLSLC_EXE}")
+    add_custom_target(compile_shaders
+        COMMAND ${CMAKE_COMMAND}
+            -D GLSLC=${GLSLC_EXE}
+            -D SHADERS_DIR=${CMAKE_SOURCE_DIR}/shaders
+            -P ${CMAKE_SOURCE_DIR}/tools/shaders/compile_shaders.cmake
+        WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+        COMMENT "Compiling .vk.glsl shaders to SPIR-V")
+else()
+    message(STATUS "glslc no encontrado — el target compile_shaders no estará disponible")
+endif()
+
 # --- AÑADIR EJECUTABLE ---
 add_executable(${PROJECT_NAME} ${APP_SOURCES} ${EXTERNAL_SOURCES})
 

Makefile

@@ -11,11 +11,12 @@ APP_NAME       := Shadertoy
 RELEASE_FOLDER := shadertoy_release
 RESOURCE_FILE  := release/shadertoy.res
 
-# Versión automática basada en la fecha actual (específica por SO)
+# Versión automática basada en la fecha actual (formato YYYY.MM.DD para que
+# CFBundleShortVersionString del bundle macOS sea conforme a la spec de Apple).
 ifeq ($(OS),Windows_NT)
-    VERSION := $(shell powershell -Command "Get-Date -Format 'yyyy-MM-dd'")
+    VERSION := $(shell powershell -Command "Get-Date -Format 'yyyy.MM.dd'")
 else
-    VERSION := $(shell date +%Y-%m-%d)
+    VERSION := $(shell date +%Y.%m.%d)
 endif
 
 # Variables específicas para Windows (usando APP_NAME)
@@ -35,6 +36,9 @@ LINUX_RELEASE               := $(TARGET_NAME)-$(VERSION)-linux.tar.gz
 # Lista completa de archivos fuente
 APP_SOURCES := \
     src/main.cpp \
+    src/rendering/shader_backend.cpp \
+    src/rendering/opengl_shader_backend.cpp \
+    src/rendering/sdl3gpu/sdl3gpu_shader_backend.cpp \
     third_party/glad/src/glad.c \
     third_party/jail_audio.cpp
 
@@ -128,8 +132,28 @@ macos_debug:
 macos_release:
 	@echo "Creando release para macOS - Version: $(VERSION)"
 
-# Verificar e instalar create-dmg si es necesario
+# Verifica dependencias necesarias (create-dmg). Si falta, intenta instalarla
-	@which create-dmg > /dev/null || (echo "Instalando create-dmg..." && brew install create-dmg)
+# con brew; si brew tampoco está, indica el comando exacto al usuario.
+	@command -v create-dmg >/dev/null 2>&1 || { \
+		echo ""; \
+		echo "============================================"; \
+		echo "  Falta la dependencia: create-dmg"; \
+		echo "============================================"; \
+		if command -v brew >/dev/null 2>&1; then \
+			echo "  Instalando con: brew install create-dmg"; \
+			brew install create-dmg || { \
+				echo ""; \
+				echo "  ERROR: 'brew install create-dmg' ha fallado."; \
+				echo "  Ejecuta el comando manualmente y vuelve a probar."; \
+				exit 1; \
+			}; \
+		else \
+			echo "  Homebrew no está instalado."; \
+			echo "  Instálalo desde https://brew.sh y luego ejecuta:"; \
+			echo "      brew install create-dmg"; \
+			exit 1; \
+		fi; \
+	}
 
 # Elimina datos de compilaciones anteriores
 	$(RMDIR) "$(RELEASE_FOLDER)"
@@ -150,6 +174,12 @@ macos_release:
 	cp LICENSE "$(RELEASE_FOLDER)"
 	cp README.md "$(RELEASE_FOLDER)"
 
+# Actualiza versión en Info.plist
+	@echo "Actualizando Info.plist con versión $(VERSION)..."
+	@RAW_VERSION=$$(echo "$(VERSION)" | sed 's/^v//'); \
+	sed -i '' '/<key>CFBundleShortVersionString<\/key>/{n;s|<string>.*</string>|<string>'"$$RAW_VERSION"'</string>|;}' "$(RELEASE_FOLDER)/$(APP_NAME).app/Contents/Info.plist"; \
+	sed -i '' '/<key>CFBundleVersion<\/key>/{n;s|<string>.*</string>|<string>'"$$RAW_VERSION"'</string>|;}' "$(RELEASE_FOLDER)/$(APP_NAME).app/Contents/Info.plist"
+
 # Compila la versión para procesadores Apple Silicon
 	$(CXX) $(APP_SOURCES) $(INCLUDES) -DMACOS_BUNDLE -DRELEASE_BUILD $(CXXFLAGS) $(LDFLAGS) -o "$(RELEASE_FOLDER)/$(APP_NAME).app/Contents/MacOS/$(TARGET_NAME)" -rpath @executable_path/../Frameworks/ -target arm64-apple-macos11
 

shaders/_common/passthrough.vert.msl

@@ -0,0 +1,19 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// Shared fullscreen-triangle vertex shader for the SDL3 GPU backend.
+// Emits uv in Shadertoy convention: (0,0) bottom-left, (1,1) top-right.
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+vertex PassthroughVOut passthrough_vs(uint vid [[vertex_id]]) {
+    const float2 positions[3] = { {-1.0, -1.0}, {3.0, -1.0}, {-1.0, 3.0} };
+    PassthroughVOut out;
+    float2 pos = positions[vid];
+    out.uv = pos * 0.5 + 0.5;
+    out.pos = float4(pos, 0.0, 1.0);
+    return out;
+}

shaders/_common/passthrough.vk.glsl

@@ -0,0 +1,17 @@
+#version 450
+
+// Shared fullscreen-triangle vertex shader for the SDL3 GPU backend.
+// Emits vUV in Shadertoy convention: (0,0) bottom-left, (1,1) top-right.
+
+layout(location = 0) out vec2 vUV;
+
+void main() {
+    const vec2 positions[3] = vec2[3](
+        vec2(-1.0, -1.0),
+        vec2( 3.0, -1.0),
+        vec2(-1.0,  3.0)
+    );
+    vec2 pos = positions[gl_VertexIndex];
+    vUV = pos * 0.5 + 0.5;
+    gl_Position = vec4(pos, 0.0, 1.0);
+}

shaders/cineshader_lava/cineshader_lava.frag.msl

@@ -0,0 +1,75 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// Cineshader Lava — edankwan
+// MSL port of cineshader_lava.vk.glsl.
+
+struct ShadertoyUBO {
+    float iTime;
+    float2 iResolution;
+};
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+static float opSmoothUnion(float d1, float d2, float k) {
+    float h = clamp(0.5 + 0.5 * (d2 - d1) / k, 0.0, 1.0);
+    return mix(d2, d1, h) - k * h * (1.0 - h);
+}
+
+static float sdSphere(float3 p, float s) {
+    return length(p) - s;
+}
+
+static float map(float3 p, float iTime) {
+    float d = 2.0;
+    for (int i = 0; i < 16; i++) {
+        float fi = float(i);
+        float time = iTime * (fract(fi * 412.531 + 0.513) - 0.5) * 2.0;
+        d = opSmoothUnion(
+            sdSphere(p + sin(time + fi * float3(52.5126, 64.62744, 632.25)) * float3(2.0, 2.0, 0.8),
+                     mix(0.5, 1.0, fract(fi * 412.531 + 0.5124))),
+            d,
+            0.4
+        );
+    }
+    return d;
+}
+
+static float3 calcNormal(float3 p, float iTime) {
+    const float h = 1e-5;
+    const float2 k = float2(1, -1);
+    return normalize(k.xyy * map(p + k.xyy * h, iTime) +
+                     k.yyx * map(p + k.yyx * h, iTime) +
+                     k.yxy * map(p + k.yxy * h, iTime) +
+                     k.xxx * map(p + k.xxx * h, iTime));
+}
+
+fragment float4 cineshader_lava_fs(PassthroughVOut in [[stage_in]],
+                                    constant ShadertoyUBO& U [[buffer(0)]]) {
+    float2 fragCoord = in.uv * U.iResolution;
+    float2 uv = fragCoord / U.iResolution;
+
+    float3 rayOri = float3((uv - 0.5) * float2(U.iResolution.x / U.iResolution.y, 1.0) * 6.0, 3.0);
+    float3 rayDir = float3(0.0, 0.0, -1.0);
+
+    float depth = 0.0;
+    float3 p = float3(0.0);
+
+    for (int i = 0; i < 64; i++) {
+        p = rayOri + rayDir * depth;
+        float dist = map(p, U.iTime);
+        depth += dist;
+        if (dist < 1e-6) { break; }
+    }
+
+    depth = min(6.0, depth);
+    float3 n = calcNormal(p, U.iTime);
+    float b = max(0.0, dot(n, float3(0.577)));
+    float3 col = (0.5 + 0.5 * cos((b + U.iTime * 3.0) + uv.xyx * 2.0 + float3(0, 2, 4))) * (0.85 + b * 0.35);
+    col *= exp(-depth * 0.15);
+
+    return float4(col, 1.0 - (depth - 0.5) / 2.0);
+}

shaders/cineshader_lava/cineshader_lava.vk.glsl

@@ -0,0 +1,77 @@
+#version 450
+
+// Name: Cineshader Lava
+// Author: edankwan
+// URL: https://www.shadertoy.com/view/3sySRK
+
+layout(location = 0) in  vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+
+layout(set = 3, binding = 0) uniform ShadertoyUBO {
+    float iTime;
+    vec2  iResolution;
+};
+
+float opSmoothUnion(float d1, float d2, float k) {
+    float h = clamp(0.5 + 0.5 * (d2 - d1) / k, 0.0, 1.0);
+    return mix(d2, d1, h) - k * h * (1.0 - h);
+}
+
+float sdSphere(vec3 p, float s) {
+    return length(p) - s;
+}
+
+float map(vec3 p) {
+    float d = 2.0;
+    for (int i = 0; i < 16; i++) {
+        float fi = float(i);
+        float time = iTime * (fract(fi * 412.531 + 0.513) - 0.5) * 2.0;
+        d = opSmoothUnion(
+            sdSphere(p + sin(time + fi * vec3(52.5126, 64.62744, 632.25)) * vec3(2.0, 2.0, 0.8), mix(0.5, 1.0, fract(fi * 412.531 + 0.5124))),
+            d,
+            0.4
+        );
+    }
+    return d;
+}
+
+vec3 calcNormal(in vec3 p) {
+    const float h = 1e-5;
+    const vec2 k = vec2(1, -1);
+    return normalize(k.xyy * map(p + k.xyy * h) +
+                     k.yyx * map(p + k.yyx * h) +
+                     k.yxy * map(p + k.yxy * h) +
+                     k.xxx * map(p + k.xxx * h));
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord) {
+    vec2 uv = fragCoord / iResolution.xy;
+
+    vec3 rayOri = vec3((uv - 0.5) * vec2(iResolution.x / iResolution.y, 1.0) * 6.0, 3.0);
+    vec3 rayDir = vec3(0.0, 0.0, -1.0);
+
+    float depth = 0.0;
+    vec3 p;
+
+    for (int i = 0; i < 64; i++) {
+        p = rayOri + rayDir * depth;
+        float dist = map(p);
+        depth += dist;
+        if (dist < 1e-6) { break; }
+    }
+
+    depth = min(6.0, depth);
+    vec3 n = calcNormal(p);
+    float b = max(0.0, dot(n, vec3(0.577)));
+    vec3 col = (0.5 + 0.5 * cos((b + iTime * 3.0) + uv.xyx * 2.0 + vec3(0, 2, 4))) * (0.85 + b * 0.35);
+    col *= exp(-depth * 0.15);
+
+    fragColor = vec4(col, 1.0 - (depth - 0.5) / 2.0);
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}

shaders/cineshader_lava/meta.txt

@@ -0,0 +1,2 @@
+Name: Cineshader Lava
+Author: edankwan

shaders/creation/creation.frag.msl

@@ -0,0 +1,42 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// Creation by Silexars — Danguafer
+// MSL port of creation.vk.glsl.
+
+struct ShadertoyUBO {
+    float iTime;
+    float2 iResolution;
+};
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+fragment float4 creation_fs(PassthroughVOut in [[stage_in]],
+                            constant ShadertoyUBO& U [[buffer(0)]]) {
+    float2 fragCoord = in.uv * U.iResolution;
+    float t = U.iTime;
+    float2 r = U.iResolution;
+
+    float3 c = float3(0.0);
+    float l = 0.0;
+    float z = t;
+    for (int i = 0; i < 3; i++) {
+        float2 p = fragCoord / r;
+        float2 uv = p;
+        p -= 0.5;
+        p.x *= r.x / r.y;
+        z += 0.07;
+        l = length(p);
+        float invl = (l > 0.0) ? (1.0 / l) : 0.0;
+        uv += p * invl * (sin(z) + 1.0) * abs(sin(l * 9.0 - z - z));
+        float2 m = fract(uv) - 0.5;
+        float denom = length(m);
+        if (denom < 1e-6) denom = 1e-6;
+        c[i] = 0.01 / denom;
+    }
+    float L = (l > 0.0) ? l : 1.0;
+    return float4(c / L, t);
+}

shaders/creation/creation.vk.glsl

@@ -0,0 +1,45 @@
+#version 450
+
+// Name: Creation by Silexars
+// Author: Danguafer
+// URL: https://www.shadertoy.com/view/XsXXDn
+
+layout(location = 0) in  vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+
+layout(set = 3, binding = 0) uniform ShadertoyUBO {
+    float iTime;
+    vec2  iResolution;
+};
+
+#define t iTime
+#define r iResolution.xy
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord) {
+    vec3 c = vec3(0.0);
+    float l;
+    float z = t;
+    for (int i = 0; i < 3; i++) {
+        vec2 uv, p = fragCoord.xy / r;
+        uv = p;
+        p -= 0.5;
+        p.x *= r.x / r.y;
+        z += 0.07;
+        l = length(p);
+        float invl = (l > 0.0) ? (1.0 / l) : 0.0;
+        uv += p * invl * (sin(z) + 1.0) * abs(sin(l * 9.0 - z - z));
+        vec2 m = mod(uv, 1.0) - 0.5;
+        float denom = length(m);
+        if (denom < 1e-6) denom = 1e-6;
+        c[i] = 0.01 / denom;
+    }
+    float L = (l > 0.0) ? l : 1.0;
+    fragColor = vec4(c / L, t);
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}

shaders/creation/meta.txt

@@ -0,0 +1,2 @@
+Name: Creation by Silexars
+Author: Danguafer

shaders/cube_lines/cube_lines.frag.msl

@@ -0,0 +1,455 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// Cube lines — Danil
+// MSL port of cube_lines.vk.glsl. The original Shadertoy is ~780 lines and
+// uses every GLSL trick (mat3 chains, arrays, fwidth-based AA, swap macros).
+//
+// Notes:
+//   - fcos() uses fwidth() like the GLSL original to soften high-frequency
+//     terms. The GLSL fallback path that divides by iResolution.y when
+//     fwidth returns 0/NaN/Inf is omitted here; the main fwidth-based
+//     branch covers virtually all fragments and the fallback is rarely
+//     hit in practice.
+//   - Optional Shadertoy defines (ANIM_SHAPE, ANIM_COLOR, ROTATION_SPEED,
+//     CAMERA_*, USE_COLOR, AA_*, ONLY_BOX, etc.) are left at their defaults
+//     just like the .vk.glsl ships them.
+
+struct ShadertoyUBO {
+    float iTime;
+    float2 iResolution;
+};
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+constant float ROTATION_SPEED = 0.8999;
+constant float tshift = 53.0;
+constant float FDIST = 0.7;
+constant float PI = 3.1415926;
+constant float3 BOXDIMS = float3(0.75, 0.75, 1.25);
+constant float IOR = 1.33;
+
+static float3x3 rotx(float a) {
+    float s = sin(a), c = cos(a);
+    return float3x3(float3(1.0, 0.0, 0.0), float3(0.0, c, s), float3(0.0, -s, c));
+}
+static float3x3 roty(float a) {
+    float s = sin(a), c = cos(a);
+    return float3x3(float3(c, 0.0, s), float3(0.0, 1.0, 0.0), float3(-s, 0.0, c));
+}
+static float3x3 rotz(float a) {
+    float s = sin(a), c = cos(a);
+    return float3x3(float3(c, s, 0.0), float3(-s, c, 0.0), float3(0.0, 0.0, 1.0));
+}
+
+static float3 fcos(float3 x) {
+    float3 w = fwidth(x);
+    return cos(x) * smoothstep(float3(3.14 * 2.0), float3(0.0), w);
+}
+
+static float3 getColor(float3 p) {
+    p = abs(p);
+    p *= 1.25;
+    p = 0.5 * p / dot(p, p);
+
+    float t = 0.13 * length(p);
+    float3 col = float3(0.3, 0.4, 0.5);
+    col += 0.12 * fcos(6.28318 * t * 1.0 + float3(0.0, 0.8, 1.1));
+    col += 0.11 * fcos(6.28318 * t * 3.1 + float3(0.3, 0.4, 0.1));
+    col += 0.10 * fcos(6.28318 * t * 5.1 + float3(0.1, 0.7, 1.1));
+    col += 0.10 * fcos(6.28318 * t * 17.1 + float3(0.2, 0.6, 0.7));
+    col += 0.10 * fcos(6.28318 * t * 31.1 + float3(0.1, 0.6, 0.7));
+    col += 0.10 * fcos(6.28318 * t * 65.1 + float3(0.0, 0.5, 0.8));
+    col += 0.10 * fcos(6.28318 * t * 115.1 + float3(0.1, 0.4, 0.7));
+    col += 0.10 * fcos(6.28318 * t * 265.1 + float3(1.1, 1.4, 2.7));
+    col = clamp(col, 0.0, 1.0);
+    return col;
+}
+
+static void calcColor(float3 ro, float3 rd, float3 nor, float d, float len, int idx,
+                      bool si, float td,
+                      thread float4& colx, thread float4& colsi) {
+    float3 pos = ro + rd * d;
+    float a = 1.0 - smoothstep(len - 0.15 * 0.5, len + 0.00001, length(pos));
+    float3 col = getColor(pos);
+    colx = float4(col, a);
+    if (si) {
+        pos = ro + rd * td;
+        float ta = 1.0 - smoothstep(len - 0.15 * 0.5, len + 0.00001, length(pos));
+        col = getColor(pos);
+        colsi = float4(col, ta);
+    }
+}
+
+static bool iBilinearPatch(float3 ro, float3 rd, float4 ps, float4 ph, float sz,
+                           thread float& t, thread float3& norm,
+                           thread bool& si, thread float& tsi, thread float3& normsi,
+                           thread float& fade, thread float& fadesi) {
+    float3 va = float3(0.0, 0.0, ph.x + ph.w - ph.y - ph.z);
+    float3 vb = float3(0.0, ps.w - ps.y, ph.z - ph.x);
+    float3 vc = float3(ps.z - ps.x, 0.0, ph.y - ph.x);
+    float3 vd = float3(ps.xy, ph.x);
+    t = -1.0;
+    tsi = -1.0;
+    si = false;
+    fade = 1.0;
+    fadesi = 1.0;
+    norm = float3(0.0, 1.0, 0.0);
+    normsi = float3(0.0, 1.0, 0.0);
+
+    float tmp = 1.0 / (vb.y * vc.x);
+    float a = 0.0, b = 0.0, c = 0.0;
+    float d = va.z * tmp;
+    float e = 0.0, f = 0.0;
+    float g = (vc.z * vb.y - vd.y * va.z) * tmp;
+    float h = (vb.z * vc.x - va.z * vd.x) * tmp;
+    float i = -1.0;
+    float j = (vd.x * vd.y * va.z + vd.z * vb.y * vc.x) * tmp - (vd.y * vb.z * vc.x + vd.x * vc.z * vb.y) * tmp;
+
+    float p = dot(float3(a, b, c), rd.xzy * rd.xzy) + dot(float3(d, e, f), rd.xzy * rd.zyx);
+    float q = dot(float3(2.0, 2.0, 2.0) * ro.xzy * rd.xyz, float3(a, b, c)) + dot(ro.xzz * rd.zxy, float3(d, d, e)) +
+              dot(ro.yyx * rd.zxy, float3(e, f, f)) + dot(float3(g, h, i), rd.xzy);
+    float r = dot(float3(a, b, c), ro.xzy * ro.xzy) + dot(float3(d, e, f), ro.xzy * ro.zyx) + dot(float3(g, h, i), ro.xzy) + j;
+
+    if (abs(p) < 0.000001) {
+        float tt = -r / q;
+        if (tt <= 0.0) return false;
+        t = tt;
+        float3 pos = ro + t * rd;
+        if (length(pos) > sz) return false;
+        float3 grad = float3(2.0) * pos.xzy * float3(a, b, c) + pos.zxz * float3(d, d, e) + pos.yyx * float3(f, e, f) + float3(g, h, i);
+        norm = -normalize(grad);
+        return true;
+    } else {
+        float sq = q * q - 4.0 * p * r;
+        if (sq < 0.0) return false;
+        float s = sqrt(sq);
+        float t0 = (-q + s) / (2.0 * p);
+        float t1 = (-q - s) / (2.0 * p);
+        float tt1 = min(t0 < 0.0 ? t1 : t0, t1 < 0.0 ? t0 : t1);
+        float tt2 = max(t0 > 0.0 ? t1 : t0, t1 > 0.0 ? t0 : t1);
+        float tt0 = tt1;
+        if (tt0 <= 0.0) return false;
+        float3 pos = ro + tt0 * rd;
+        bool ru = step(sz, length(pos)) > 0.5;
+        if (ru) {
+            tt0 = tt2;
+            pos = ro + tt0 * rd;
+        }
+        if (tt0 <= 0.0) return false;
+        bool ru2 = step(sz, length(pos)) > 0.5;
+        if (ru2) return false;
+
+        if ((tt2 > 0.0) && (!ru) && !(step(sz, length(ro + tt2 * rd)) > 0.5)) {
+            si = true;
+            fadesi = s;
+            tsi = tt2;
+            float3 tpos = ro + tsi * rd;
+            float3 tgrad = float3(2.0) * tpos.xzy * float3(a, b, c) + tpos.zxz * float3(d, d, e) +
+                           tpos.yyx * float3(f, e, f) + float3(g, h, i);
+            normsi = -normalize(tgrad);
+        }
+
+        fade = s;
+        t = tt0;
+        float3 grad = float3(2.0) * pos.xzy * float3(a, b, c) + pos.zxz * float3(d, d, e) + pos.yyx * float3(f, e, f) + float3(g, h, i);
+        norm = -normalize(grad);
+        return true;
+    }
+}
+
+static float dot2(float3 v) { return dot(v, v); }
+
+static float segShadow(float3 ro, float3 rd, float3 pa, float sh) {
+    float dm = dot(rd.yz, rd.yz);
+    float k1 = (ro.x - pa.x) * dm;
+    float k2 = (ro.x + pa.x) * dm;
+    float2 k5 = (ro.yz + pa.yz) * dm;
+    float k3 = dot(ro.yz + pa.yz, rd.yz);
+    float2 k4 = (pa.yz + pa.yz) * rd.yz;
+    float2 k6 = (pa.yz + pa.yz) * dm;
+
+    for (int i = 0; i < 4; i++) {
+        float2 s = float2(i & 1, i >> 1);
+        float t = dot(s, k4) - k3;
+        if (t > 0.0) {
+            sh = min(sh, dot2(float3(clamp(-rd.x * t, k1, k2), k5 - k6 * s) + rd * t) / (t * t));
+        }
+    }
+    return sh;
+}
+
+static float boxSoftShadow(float3 ro, float3 rd, float3 rad, float sk) {
+    rd += 0.0001 * (1.0 - abs(sign(rd)));
+    float3 rdd = rd;
+    float3 roo = ro;
+
+    float3 m = 1.0 / rdd;
+    float3 n = m * roo;
+    float3 k = abs(m) * rad;
+
+    float3 t1 = -n - k;
+    float3 t2 = -n + k;
+
+    float tN = max(max(t1.x, t1.y), t1.z);
+    float tF = min(min(t2.x, t2.y), t2.z);
+
+    if (tN < tF && tF > 0.0) return 0.0;
+
+    float sh = 1.0;
+    sh = segShadow(roo.xyz, rdd.xyz, rad.xyz, sh);
+    sh = segShadow(roo.yzx, rdd.yzx, rad.yzx, sh);
+    sh = segShadow(roo.zxy, rdd.zxy, rad.zxy, sh);
+    sh = clamp(sk * sqrt(sh), 0.0, 1.0);
+    return sh * sh * (3.0 - 2.0 * sh);
+}
+
+static float boxRay(float3 ro, float3 rd, float3 r, thread float3& nn, bool entering) {
+    rd += 0.0001 * (1.0 - abs(sign(rd)));
+    float3 dr = 1.0 / rd;
+    float3 n = ro * dr;
+    float3 k = r * abs(dr);
+
+    float3 pin = -k - n;
+    float3 pout = k - n;
+    float tin = max(pin.x, max(pin.y, pin.z));
+    float tout = min(pout.x, min(pout.y, pout.z));
+    if (tin > tout) return -1.0;
+    if (entering) {
+        nn = -sign(rd) * step(pin.zxy, pin.xyz) * step(pin.yzx, pin.xyz);
+    } else {
+        nn = sign(rd) * step(pout.xyz, pout.zxy) * step(pout.xyz, pout.yzx);
+    }
+    return entering ? tin : tout;
+}
+
+static float3 bgcol(float3 rd) {
+    return mix(float3(0.01), float3(0.336, 0.458, 0.668), 1.0 - pow(abs(rd.z + 0.25), 1.3));
+}
+
+static float3 background(float3 ro, float3 rd, float3 l_dir, thread float& alpha) {
+    float t = (-BOXDIMS.z - ro.z) / rd.z;
+    alpha = 0.0;
+    float3 bgc = bgcol(rd);
+    if (t < 0.0) return bgc;
+    float2 uv = ro.xy + t * rd.xy;
+    float shad = boxSoftShadow((ro + t * rd), normalize(l_dir + float3(0.0, 0.0, 1.0)) * rotz(PI * 0.65), BOXDIMS, 1.5);
+    float aofac = smoothstep(-0.95, 0.75, length(abs(uv) - min(abs(uv), float2(0.45))));
+    aofac = min(aofac, smoothstep(-0.65, 1.0, shad));
+    float lght = max(dot(normalize(ro + t * rd + float3(0.0, -0.0, -5.0)), normalize(l_dir - float3(0.0, 0.0, 1.0)) * rotz(PI * 0.65)), 0.0);
+    float3 col = mix(float3(0.4), float3(0.71, 0.772, 0.895), lght * lght * aofac + 0.05) * aofac;
+    alpha = 1.0 - smoothstep(7.0, 10.0, length(uv));
+    return mix(col * length(col) * 0.8, bgc, smoothstep(7.0, 10.0, length(uv)));
+}
+
+static float4 insides(float3 ro, float3 rd, float3 nor_c, float3 l_dir, thread float& tout) {
+    tout = -1.0;
+
+    float pi = 3.1415926;
+
+    if (abs(nor_c.x) > 0.5) {
+        rd = rd.xzy * nor_c.x;
+        ro = ro.xzy * nor_c.x;
+    } else if (abs(nor_c.z) > 0.5) {
+        l_dir = l_dir * roty(pi);
+        rd = rd.yxz * nor_c.z;
+        ro = ro.yxz * nor_c.z;
+    } else if (abs(nor_c.y) > 0.5) {
+        l_dir = l_dir * rotz(-pi * 0.5);
+        rd = rd * nor_c.y;
+        ro = ro * nor_c.y;
+    }
+
+    const float curvature = 0.5;
+    float bil_size = 1.0;
+    float4 ps = float4(-bil_size, -bil_size, bil_size, bil_size) * curvature;
+    float4 ph = float4(-bil_size, bil_size, bil_size, -bil_size) * curvature;
+
+    float4 colx[3] = { float4(0.0), float4(0.0), float4(0.0) };
+    float3 dx[3] = { float3(-1.0), float3(-1.0), float3(-1.0) };
+    float4 colxsi[3] = { float4(0.0), float4(0.0), float4(0.0) };
+    int order[3] = { 0, 1, 2 };
+
+    for (int i = 0; i < 3; i++) {
+        if (abs(nor_c.x) > 0.5) {
+            ro = ro * rotz(-pi * (1.0 / 3.0));
+            rd = rd * rotz(-pi * (1.0 / 3.0));
+        } else if (abs(nor_c.z) > 0.5) {
+            ro = ro * rotz(pi * (1.0 / 3.0));
+            rd = rd * rotz(pi * (1.0 / 3.0));
+        } else if (abs(nor_c.y) > 0.5) {
+            ro = ro * rotx(pi * (1.0 / 3.0));
+            rd = rd * rotx(pi * (1.0 / 3.0));
+        }
+        float3 normnew;
+        float tnew;
+        bool si;
+        float tsi;
+        float3 normsi;
+        float fade;
+        float fadesi;
+
+        if (iBilinearPatch(ro, rd, ps, ph, bil_size, tnew, normnew, si, tsi, normsi, fade, fadesi)) {
+            if (tnew > 0.0) {
+                float4 tcol, tcolsi;
+                calcColor(ro, rd, normnew, tnew, bil_size, i, si, tsi, tcol, tcolsi);
+                if (tcol.a > 0.0) {
+                    dx[i] = float3(tnew, float(si), tsi);
+
+                    float dif = clamp(dot(normnew, l_dir), 0.0, 1.0);
+                    float amb = clamp(0.5 + 0.5 * dot(normnew, l_dir), 0.0, 1.0);
+
+                    {
+                        float3 shad = float3(0.32, 0.43, 0.54) * amb + float3(1.0, 0.9, 0.7) * dif;
+                        const float3 tcr = float3(1.0, 0.21, 0.11);
+                        float ta = clamp(length(tcol.rgb), 0.0, 1.0);
+                        tcol = clamp(tcol * tcol * 2.0, 0.0, 1.0);
+                        float4 tvalx = float4(tcol.rgb * shad * 1.4 + 3.0 * (tcr * tcol.rgb) * clamp(1.0 - (amb + dif), 0.0, 1.0), min(tcol.a, ta));
+                        tvalx.rgb = clamp(2.0 * tvalx.rgb * tvalx.rgb, 0.0, 1.0);
+                        tvalx *= min(fade * 5.0, 1.0);
+                        colx[i] = tvalx;
+                    }
+                    if (si) {
+                        dif = clamp(dot(normsi, l_dir), 0.0, 1.0);
+                        amb = clamp(0.5 + 0.5 * dot(normsi, l_dir), 0.0, 1.0);
+                        float3 shad = float3(0.32, 0.43, 0.54) * amb + float3(1.0, 0.9, 0.7) * dif;
+                        const float3 tcr = float3(1.0, 0.21, 0.11);
+                        float ta = clamp(length(tcolsi.rgb), 0.0, 1.0);
+                        tcolsi = clamp(tcolsi * tcolsi * 2.0, 0.0, 1.0);
+                        float4 tvalx = float4(tcolsi.rgb * shad + 3.0 * (tcr * tcolsi.rgb) * clamp(1.0 - (amb + dif), 0.0, 1.0), min(tcolsi.a, ta));
+                        tvalx.rgb = clamp(2.0 * tvalx.rgb * tvalx.rgb, 0.0, 1.0);
+                        tvalx.rgb *= min(fadesi * 5.0, 1.0);
+                        colxsi[i] = tvalx;
+                    }
+                }
+            }
+        }
+    }
+
+    // sort by dx[*].x descending (3 passes of bubble sort like the GLSL)
+    if (dx[0].x < dx[1].x) { float3 tv = dx[0]; dx[0] = dx[1]; dx[1] = tv; int ti = order[0]; order[0] = order[1]; order[1] = ti; }
+    if (dx[1].x < dx[2].x) { float3 tv = dx[1]; dx[1] = dx[2]; dx[2] = tv; int ti = order[1]; order[1] = order[2]; order[2] = ti; }
+    if (dx[0].x < dx[1].x) { float3 tv = dx[0]; dx[0] = dx[1]; dx[1] = tv; int ti = order[0]; order[0] = order[1]; order[1] = ti; }
+
+    tout = max(max(dx[0].x, dx[1].x), dx[2].x);
+
+    float a = 1.0;
+    if (dx[0].y < 0.5) {
+        a = colx[order[0]].a;
+    }
+
+    bool rul[3] = {
+        ((dx[0].y > 0.5) && (dx[1].x <= 0.0)),
+        ((dx[1].y > 0.5) && (dx[0].x > dx[1].z)),
+        ((dx[2].y > 0.5) && (dx[1].x > dx[2].z))
+    };
+    for (int k = 0; k < 3; k++) {
+        if (rul[k]) {
+            float4 tcolxsi = colxsi[order[k]];
+            float4 tcolx = colx[order[k]];
+            float4 tvalx = mix(tcolxsi, tcolx, tcolx.a);
+            float4 tvalx2 = mix(float4(0.0), tvalx, max(tcolx.a, tcolxsi.a));
+            colx[order[k]] = tvalx2;
+        }
+    }
+
+    float a1 = (dx[1].y < 0.5) ? colx[order[1]].a : ((dx[1].z > dx[0].x) ? colx[order[1]].a : 1.0);
+    float a2 = (dx[2].y < 0.5) ? colx[order[2]].a : ((dx[2].z > dx[1].x) ? colx[order[2]].a : 1.0);
+    float3 col = mix(mix(colx[order[0]].rgb, colx[order[1]].rgb, a1), colx[order[2]].rgb, a2);
+    a = max(max(a, a1), a2);
+    return float4(col, a);
+}
+
+fragment float4 cube_lines_fs(PassthroughVOut in [[stage_in]],
+                               constant ShadertoyUBO& U [[buffer(0)]]) {
+    float2 fragCoord = in.uv * U.iResolution;
+    float iTime = U.iTime;
+
+    float3 l_dir = normalize(float3(0.0, 1.0, 0.0));
+    l_dir = l_dir * rotz(0.5);
+    float mouseY = PI * 0.49 - smoothstep(0.0, 8.5, fmod((iTime + tshift) * 0.33, 25.0))
+                            * (1.0 - smoothstep(14.0, 24.0, fmod((iTime + tshift) * 0.33, 25.0))) * 0.55 * PI;
+    float mouseX = -2.0 * PI - 0.25 * (iTime * ROTATION_SPEED + tshift);
+
+    float3 eye = 4.0 * float3(cos(mouseX) * cos(mouseY), sin(mouseX) * cos(mouseY), sin(mouseY));
+    float3 w = normalize(-eye);
+    float3 up = float3(0.0, 0.0, 1.0);
+    float3 u = normalize(cross(w, up));
+    float3 v = cross(u, w);
+
+    float4 tot = float4(0.0);
+    float2 uv = (fragCoord - 0.5 * U.iResolution) / U.iResolution.x;
+    float3 rd = normalize(w * FDIST + uv.x * u + uv.y * v);
+
+    float3 ni;
+    float t = boxRay(eye, rd, BOXDIMS, ni, true);
+    float3 ro = eye + t * rd;
+    float2 coords = ro.xy * ni.z / BOXDIMS.xy + ro.yz * ni.x / BOXDIMS.yz + ro.zx * ni.y / BOXDIMS.zx;
+    float fadeborders = (1.0 - smoothstep(0.915, 1.05, abs(coords.x))) * (1.0 - smoothstep(0.915, 1.05, abs(coords.y)));
+
+    if (t > 0.0) {
+        float3 col = float3(0.0);
+        float R0 = (IOR - 1.0) / (IOR + 1.0);
+        R0 *= R0;
+
+        float2 theta = float2(0.0);
+        float3 n = float3(cos(theta.x) * sin(theta.y), sin(theta.x) * sin(theta.y), cos(theta.y));
+
+        float3 nr = n.zxy * ni.x + n.yzx * ni.y + n.xyz * ni.z;
+        float3 rdr = reflect(rd, nr);
+        float talpha;
+        float3 reflcol = background(ro, rdr, l_dir, talpha);
+
+        float3 rd2 = refract(rd, nr, 1.0 / IOR);
+
+        float accum = 1.0;
+        float3 no2 = ni;
+        float3 ro_refr = ro;
+
+        float4 colo[2] = { float4(0.0), float4(0.0) };
+
+        for (int j = 0; j < 2; j++) {
+            float tb;
+            float2 coords2 = ro_refr.xy * no2.z + ro_refr.yz * no2.x + ro_refr.zx * no2.y;
+            float3 eye2 = float3(coords2, -1.0);
+            float3 rd2trans = rd2.yzx * no2.x + rd2.zxy * no2.y + rd2.xyz * no2.z;
+
+            rd2trans.z = -rd2trans.z;
+            float4 internalcol = insides(eye2, rd2trans, no2, l_dir, tb);
+            if (tb > 0.0) {
+                internalcol.rgb *= accum;
+                colo[j] = internalcol;
+            }
+
+            if ((tb <= 0.0) || (internalcol.a < 1.0)) {
+                float tout = boxRay(ro_refr, rd2, BOXDIMS, no2, false);
+                no2 = n.zyx * no2.x + n.xzy * no2.y + n.yxz * no2.z;
+                float3 rout = ro_refr + tout * rd2;
+                float3 rdout = refract(rd2, -no2, IOR);
+                float fresnel2 = R0 + (1.0 - R0) * pow(1.0 - dot(rdout, no2), 1.3);
+                rd2 = reflect(rd2, -no2);
+
+                ro_refr = rout;
+                ro_refr.z = max(ro_refr.z, -0.999);
+
+                accum *= fresnel2;
+            }
+        }
+        float fresnel = R0 + (1.0 - R0) * pow(1.0 - dot(-rd, nr), 5.0);
+        col = mix(mix(colo[1].rgb * colo[1].a, colo[0].rgb, colo[0].a) * fadeborders, reflcol, pow(fresnel, 1.5));
+        col = clamp(col, 0.0, 1.0);
+
+        float cineshader_alpha = clamp(0.15 * dot(eye, ro), 0.0, 1.0);
+        tot += float4(col, cineshader_alpha);
+    } else {
+        float alpha;
+        tot += float4(background(eye, rd, l_dir, alpha), 0.15);
+    }
+
+    float4 outColor = tot;
+    outColor.rgb = clamp(outColor.rgb, 0.0, 1.0);
+    return outColor;
+}

shaders/cube_lines/cube_lines.vk.glsl

@@ -0,0 +1,782 @@
+#version 450
+
+// Name: Cube lines
+// Author: Danil
+// URL: https://www.shadertoy.com/view/NslGRN
+
+layout(location = 0) in  vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+
+layout(set = 3, binding = 0) uniform ShadertoyUBO {
+    float iTime;
+    vec2  iResolution;
+};
+
+
+// Note: Original shader uses iChannel0 for background blending (optional feature)
+// Since we don't support texture channels, that line is commented out
+// The shader works perfectly without it in default mode
+
+// Created by Danil (2021+) https://cohost.org/arugl
+// License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
+// self https://www.shadertoy.com/view/NslGRN
+
+
+// --defines for "DESKTOP WALLPAPERS" that use this shader--
+// comment or uncomment every define to make it work (add or remove "//" before #define)
+
+
+// this shadertoy use ALPHA, NO_ALPHA set alpha to 1, BG_ALPHA set background as alpha
+// iChannel0 used as background if alpha ignored by wallpaper-app
+//#define NO_ALPHA
+//#define BG_ALPHA
+//#define SHADOW_ALPHA
+//#define ONLY_BOX
+
+
+// save PERFORMANCE by disabling shadow
+//#define NO_SHADOW
+
+
+// static CAMERA position, 0.49 on top, 0.001 horizontal
+//#define CAMERA_POS 0.049
+
+
+// speed of ROTATION
+#define ROTATION_SPEED 0.8999
+
+
+// static SHAPE form, default 0.5
+//#define STATIC_SHAPE 0.15
+
+
+// static SCALE far/close to camera, 2.0 is default, exampe 0.5 or 10.0
+//#define CAMERA_FAR 0.1
+
+
+// ANIMATION shape change
+//#define ANIM_SHAPE
+
+
+// ANIMATION color change
+//#define ANIM_COLOR
+
+
+// custom COLOR, and change those const values
+//#define USE_COLOR
+const vec3 color_blue=vec3(0.5,0.65,0.8);
+const vec3 color_red=vec3(0.99,0.2,0.1);
+
+
+// use 4xAA for cube only (set 2-4-etc level of AA)
+//#define AA_CUBE 4
+
+// use 4xAA for everything - derivative filtering will not be used, look fcos2
+// this is very slow - DO NOT USE
+//#define AA_ALL 4
+
+
+
+// --shader code--
+
+// Layers sorted and support transparency and self-intersection-transparency
+// Antialiasing is only dFd. (with some dFd fixes around edges)
+
+// using iq's intersectors: https://iquilezles.org/articles/intersectors
+// using https://www.shadertoy.com/view/ltKBzG
+// using https://www.shadertoy.com/view/tsVXzh
+// using https://www.shadertoy.com/view/WlffDn
+// using https://www.shadertoy.com/view/WslGz4
+
+#define tshift 53.
+
+// reflect back side
+//#define backside_refl
+
+// Camera with mouse
+// #define MOUSE_control (disabled - no iMouse support)
+
+// min(iFrame,0) does not speedup compilation in ANGLE
+#define ANGLE_loops 0
+
+
+// this shader discover Nvidia bug with arrays https://www.shadertoy.com/view/NslGR4
+// use DEBUG with BUG, BUG trigger that bug and one layer will be white on Nvidia in OpenGL
+//#define DEBUG
+//#define BUG
+
+#define FDIST 0.7
+#define PI 3.1415926
+#define GROUNDSPACING 0.5
+#define GROUNDGRID 0.05
+#define BOXDIMS vec3(0.75, 0.75, 1.25)
+
+#define IOR 1.33
+
+mat3 rotx(float a){float s = sin(a);float c = cos(a);return mat3(vec3(1.0, 0.0, 0.0), vec3(0.0, c, s), vec3(0.0, -s, c));  }
+mat3 roty(float a){float s = sin(a);float c = cos(a);return mat3(vec3(c, 0.0, s), vec3(0.0, 1.0, 0.0), vec3(-s, 0.0, c));}
+mat3 rotz(float a){float s = sin(a);float c = cos(a);return mat3(vec3(c, s, 0.0), vec3(-s, c, 0.0), vec3(0.0, 0.0, 1.0 ));}
+
+vec3 fcos1(vec3 x) {
+    vec3 w = fwidth(x);
+    //if((length(w)==0.))return vec3(0.); // dFd fix2
+    //w*=0.; //test
+    float lw=length(w);
+    if((lw==0.)||isnan(lw)||isinf(lw)){vec3 tc=vec3(0.); for(int i=0;i<8;i++)tc+=cos(x+x*float(i-4)*(0.01*400./iResolution.y));return tc/8.;}
+
+    return cos(x) * smoothstep(3.14 * 2.0, 0.0, w);
+}
+
+vec3 fcos2( vec3 x){return cos(x);}
+vec3 fcos( vec3 x){
+#ifdef AA_ALL
+    return fcos2(x);
+#else
+    return fcos1(x);
+#endif
+}
+
+vec3 getColor(vec3 p)
+{
+    // dFd fix, dFd broken on borders, but it fix only top level dFd, self intersection has border
+    //if (length(p) > 0.99)return vec3(0.);
+    p = abs(p);
+
+    p *= 01.25;
+    p = 0.5 * p / dot(p, p);
+#ifdef ANIM_COLOR
+    p+=0.072*iTime;
+#endif
+
+    float t = (0.13) * length(p);
+    vec3 col = vec3(0.3, 0.4, 0.5);
+    col += 0.12 * fcos(6.28318 * t * 1.0 + vec3(0.0, 0.8, 1.1));
+    col += 0.11 * fcos(6.28318 * t * 3.1 + vec3(0.3, 0.4, 0.1));
+    col += 0.10 * fcos(6.28318 * t * 5.1 + vec3(0.1, 0.7, 1.1));
+    col += 0.10 * fcos(6.28318 * t * 17.1 + vec3(0.2, 0.6, 0.7));
+    col += 0.10 * fcos(6.28318 * t * 31.1 + vec3(0.1, 0.6, 0.7));
+    col += 0.10 * fcos(6.28318 * t * 65.1 + vec3(0.0, 0.5, 0.8));
+    col += 0.10 * fcos(6.28318 * t * 115.1 + vec3(0.1, 0.4, 0.7));
+    col += 0.10 * fcos(6.28318 * t * 265.1 + vec3(1.1, 1.4, 2.7));
+    col = clamp(col, 0., 1.);
+
+    return col;
+}
+
+void calcColor(vec3 ro, vec3 rd, vec3 nor, float d, float len, int idx, bool si, float td, out vec4 colx,
+               out vec4 colsi)
+{
+
+    vec3 pos = (ro + rd * d);
+#ifdef DEBUG
+    float a = 1. - smoothstep(len - 0.15, len + 0.00001, length(pos));
+    if (idx == 0)colx = vec4(1., 0., 0., a);
+    if (idx == 1)colx = vec4(0., 1., 0., a);
+    if (idx == 2)colx = vec4(0., 0., 1., a);
+    if (si)
+    {
+        pos = (ro + rd * td);
+        float ta = 1. - smoothstep(len - 0.15, len + 0.00001, length(pos));
+        if (idx == 0)colsi = vec4(1., 0., 0., ta);
+        if (idx == 1)colsi = vec4(0., 1., 0., ta);
+        if (idx == 2)colsi = vec4(0., 0., 1., ta);
+    }
+#else
+    float a = 1. - smoothstep(len - 0.15*0.5, len + 0.00001, length(pos));
+    //a=1.;
+    vec3 col = getColor(pos);
+    colx = vec4(col, a);
+    if (si)
+    {
+        pos = (ro + rd * td);
+        float ta = 1. - smoothstep(len - 0.15*0.5, len + 0.00001, length(pos));
+        //ta=1.;
+        col = getColor(pos);
+        colsi = vec4(col, ta);
+    }
+#endif
+}
+
+// xSI is self intersect data, fade to fix dFd on edges
+bool iBilinearPatch(in vec3 ro, in vec3 rd, in vec4 ps, in vec4 ph, in float sz, out float t, out vec3 norm,
+                    out bool si, out float tsi, out vec3 normsi, out float fade, out float fadesi)
+{
+    vec3 va = vec3(0.0, 0.0, ph.x + ph.w - ph.y - ph.z);
+    vec3 vb = vec3(0.0, ps.w - ps.y, ph.z - ph.x);
+    vec3 vc = vec3(ps.z - ps.x, 0.0, ph.y - ph.x);
+    vec3 vd = vec3(ps.xy, ph.x);
+    t = -1.;
+    tsi = -1.;
+    si = false;
+    fade = 1.;
+    fadesi = 1.;
+    norm=vec3(0.,1.,0.);normsi=vec3(0.,1.,0.);
+
+    float tmp = 1.0 / (vb.y * vc.x);
+    float a = 0.0;
+    float b = 0.0;
+    float c = 0.0;
+    float d = va.z * tmp;
+    float e = 0.0;
+    float f = 0.0;
+    float g = (vc.z * vb.y - vd.y * va.z) * tmp;
+    float h = (vb.z * vc.x - va.z * vd.x) * tmp;
+    float i = -1.0;
+    float j = (vd.x * vd.y * va.z + vd.z * vb.y * vc.x) * tmp - (vd.y * vb.z * vc.x + vd.x * vc.z * vb.y) * tmp;
+
+    float p = dot(vec3(a, b, c), rd.xzy * rd.xzy) + dot(vec3(d, e, f), rd.xzy * rd.zyx);
+    float q = dot(vec3(2.0, 2.0, 2.0) * ro.xzy * rd.xyz, vec3(a, b, c)) + dot(ro.xzz * rd.zxy, vec3(d, d, e)) +
+              dot(ro.yyx * rd.zxy, vec3(e, f, f)) + dot(vec3(g, h, i), rd.xzy);
+    float r =
+        dot(vec3(a, b, c), ro.xzy * ro.xzy) + dot(vec3(d, e, f), ro.xzy * ro.zyx) + dot(vec3(g, h, i), ro.xzy) + j;
+
+    if (abs(p) < 0.000001)
+    {
+        float tt = -r / q;
+        if (tt <= 0.)
+            return false;
+        t = tt;
+        // normal
+
+        vec3 pos = ro + t * rd;
+        if(length(pos)>sz)return false;
+        vec3 grad =
+            vec3(2.0) * pos.xzy * vec3(a, b, c) + pos.zxz * vec3(d, d, e) + pos.yyx * vec3(f, e, f) + vec3(g, h, i);
+        norm = -normalize(grad);
+        return true;
+    }
+    else
+    {
+        float sq = q * q - 4.0 * p * r;
+        if (sq < 0.0)
+        {
+            return false;
+        }
+        else
+        {
+            float s = sqrt(sq);
+            float t0 = (-q + s) / (2.0 * p);
+            float t1 = (-q - s) / (2.0 * p);
+            float tt1 = min(t0 < 0.0 ? t1 : t0, t1 < 0.0 ? t0 : t1);
+            float tt2 = max(t0 > 0.0 ? t1 : t0, t1 > 0.0 ? t0 : t1);
+            float tt0 = tt1;
+            if (tt0 <= 0.)
+                return false;
+            vec3 pos = ro + tt0 * rd;
+            // black border on end of circle and self intersection with alpha come because dFd
+            // uncomment this to see or rename fcos2 to fcos
+            //sz+=0.3;
+            bool ru = step(sz, length(pos)) > 0.5;
+            if (ru)
+            {
+                tt0 = tt2;
+                pos = ro + tt0 * rd;
+            }
+            if (tt0 <= 0.)
+                return false;
+            bool ru2 = step(sz, length(pos)) > 0.5;
+            if (ru2)
+                return false;
+
+            // self intersect
+            if ((tt2 > 0.) && ((!ru)) && !(step(sz, length(ro + tt2 * rd)) > 0.5))
+            {
+                si = true;
+                fadesi=s;
+                tsi = tt2;
+                vec3 tpos = ro + tsi * rd;
+                // normal
+                vec3 tgrad = vec3(2.0) * tpos.xzy * vec3(a, b, c) + tpos.zxz * vec3(d, d, e) +
+                             tpos.yyx * vec3(f, e, f) + vec3(g, h, i);
+                normsi = -normalize(tgrad);
+            }
+
+            fade=s;
+            t = tt0;
+            // normal
+            vec3 grad =
+                vec3(2.0) * pos.xzy * vec3(a, b, c) + pos.zxz * vec3(d, d, e) + pos.yyx * vec3(f, e, f) + vec3(g, h, i);
+            norm = -normalize(grad);
+
+            return true;
+        }
+    }
+}
+
+float dot2( in vec3 v ) { return dot(v,v); }
+
+float segShadow( in vec3 ro, in vec3 rd, in vec3 pa, float sh )
+{
+    float dm = dot(rd.yz,rd.yz);
+    float k1 = (ro.x-pa.x)*dm;
+    float k2 = (ro.x+pa.x)*dm;
+    vec2  k5 = (ro.yz+pa.yz)*dm;
+    float k3 = dot(ro.yz+pa.yz,rd.yz);
+    vec2  k4 = (pa.yz+pa.yz)*rd.yz;
+    vec2  k6 = (pa.yz+pa.yz)*dm;
+
+    for( int i=0; i<4 + ANGLE_loops; i++ )
+    {
+        vec2  s = vec2(i&1,i>>1);
+        float t = dot(s,k4) - k3;
+
+        if( t>0.0 )
+        sh = min(sh,dot2(vec3(clamp(-rd.x*t,k1,k2),k5-k6*s)+rd*t)/(t*t));
+    }
+    return sh;
+}
+
+float boxSoftShadow( in vec3 ro, in vec3 rd, in vec3 rad, in float sk )
+{
+    rd += 0.0001 * (1.0 - abs(sign(rd)));
+    vec3 rdd = rd;
+    vec3 roo = ro;
+
+    vec3 m = 1.0/rdd;
+    vec3 n = m*roo;
+    vec3 k = abs(m)*rad;
+
+    vec3 t1 = -n - k;
+    vec3 t2 = -n + k;
+
+    float tN = max( max( t1.x, t1.y ), t1.z );
+    float tF = min( min( t2.x, t2.y ), t2.z );
+
+    if( tN<tF && tF>0.0) return 0.0;
+
+    float sh = 1.0;
+    sh = segShadow( roo.xyz, rdd.xyz, rad.xyz, sh );
+    sh = segShadow( roo.yzx, rdd.yzx, rad.yzx, sh );
+    sh = segShadow( roo.zxy, rdd.zxy, rad.zxy, sh );
+    sh = clamp(sk*sqrt(sh),0.0,1.0);
+    return sh*sh*(3.0-2.0*sh);
+}
+
+float box(in vec3 ro, in vec3 rd, in vec3 r, out vec3 nn, bool entering)
+{
+    rd += 0.0001 * (1.0 - abs(sign(rd)));
+    vec3 dr = 1.0 / rd;
+    vec3 n = ro * dr;
+    vec3 k = r * abs(dr);
+
+    vec3 pin = -k - n;
+    vec3 pout = k - n;
+    float tin = max(pin.x, max(pin.y, pin.z));
+    float tout = min(pout.x, min(pout.y, pout.z));
+    if (tin > tout)
+        return -1.;
+    if (entering)
+    {
+        nn = -sign(rd) * step(pin.zxy, pin.xyz) * step(pin.yzx, pin.xyz);
+    }
+    else
+    {
+        nn = sign(rd) * step(pout.xyz, pout.zxy) * step(pout.xyz, pout.yzx);
+    }
+    return entering ? tin : tout;
+}
+
+vec3 bgcol(in vec3 rd)
+{
+    return mix(vec3(0.01), vec3(0.336, 0.458, .668), 1. - pow(abs(rd.z+0.25), 1.3));
+}
+
+vec3 background(in vec3 ro, in vec3 rd , vec3 l_dir, out float alpha)
+{
+#ifdef ONLY_BOX
+alpha=0.;
+return vec3(0.01);
+#endif
+    float t = (-BOXDIMS.z - ro.z) / rd.z;
+    alpha=0.;
+    vec3 bgc = bgcol(rd);
+    if (t < 0.)
+        return bgc;
+    vec2 uv = ro.xy + t * rd.xy;
+#ifdef NO_SHADOW
+    float shad=1.;
+#else
+    float shad = boxSoftShadow((ro + t * rd), normalize(l_dir+vec3(0.,0.,1.))*rotz(PI*0.65) , BOXDIMS, 1.5);
+#endif
+    float aofac = smoothstep(-0.95, .75, length(abs(uv) - min(abs(uv), vec2(0.45))));
+    aofac = min(aofac,smoothstep(-0.65, 1., shad));
+    float lght=max(dot(normalize(ro + t * rd+vec3(0.,-0.,-5.)), normalize(l_dir-vec3(0.,0.,1.))*rotz(PI*0.65)), 0.0);
+    vec3 col = mix(vec3(0.4), vec3(.71,.772,0.895), lght*lght* aofac+ 0.05) * aofac;
+    alpha=1.-smoothstep(7.,10.,length(uv));
+#ifdef SHADOW_ALPHA
+    //alpha=clamp(alpha*max(lght*lght*0.95,(1.-aofac)*1.25),0.,1.);
+    alpha=clamp(alpha*(1.-aofac)*1.25,0.,1.);
+#endif
+    return mix(col*length(col)*0.8,bgc,smoothstep(7.,10.,length(uv)));
+}
+
+#define swap(a,b) tv=a;a=b;b=tv
+
+vec4 insides(vec3 ro, vec3 rd, vec3 nor_c, vec3 l_dir, out float tout)
+{
+    tout = -1.;
+    vec3 trd=rd;
+
+    vec3 col = vec3(0.);
+
+    float pi = 3.1415926;
+
+    if (abs(nor_c.x) > 0.5)
+    {
+        rd = rd.xzy * nor_c.x;
+        ro = ro.xzy * nor_c.x;
+    }
+    else if (abs(nor_c.z) > 0.5)
+    {
+        l_dir *= roty(pi);
+        rd = rd.yxz * nor_c.z;
+        ro = ro.yxz * nor_c.z;
+    }
+    else if (abs(nor_c.y) > 0.5)
+    {
+        l_dir *= rotz(-pi * 0.5);
+        rd = rd * nor_c.y;
+        ro = ro * nor_c.y;
+    }
+
+#ifdef ANIM_SHAPE
+    float curvature = (0.001+1.5-1.5*smoothstep(0.,8.5,mod((iTime+tshift)*0.44,20.))*(1.-smoothstep(10.,18.5,mod((iTime+tshift)*0.44,20.))));
+    // curvature(to not const above) make compilation on Angle 15+ sec
+#else
+#ifdef STATIC_SHAPE
+    const float curvature = STATIC_SHAPE;
+#else
+    const float curvature = .5;
+#endif
+#endif
+    float bil_size = 1.;
+    vec4 ps = vec4(-bil_size, -bil_size, bil_size, bil_size) * curvature;
+    vec4 ph = vec4(-bil_size, bil_size, bil_size, -bil_size) * curvature;
+
+    vec4 [3]colx=vec4[3](vec4(0.),vec4(0.),vec4(0.));
+    vec3 [3]dx=vec3[3](vec3(-1.),vec3(-1.),vec3(-1.));
+    vec4 [3]colxsi=vec4[3](vec4(0.),vec4(0.),vec4(0.));
+    int [3]order=int[3](0,1,2);
+
+    for (int i = 0; i < 3 + ANGLE_loops; i++)
+    {
+        if (abs(nor_c.x) > 0.5)
+        {
+            ro *= rotz(-pi * (1. / float(3)));
+            rd *= rotz(-pi * (1. / float(3)));
+        }
+        else if (abs(nor_c.z) > 0.5)
+        {
+            ro *= rotz(pi * (1. / float(3)));
+            rd *= rotz(pi * (1. / float(3)));
+        }
+        else if (abs(nor_c.y) > 0.5)
+        {
+            ro *= rotx(pi * (1. / float(3)));
+            rd *= rotx(pi * (1. / float(3)));
+        }
+        vec3 normnew;
+        float tnew;
+        bool si;
+        float tsi;
+        vec3 normsi;
+        float fade;
+        float fadesi;
+
+        if (iBilinearPatch(ro, rd, ps, ph, bil_size, tnew, normnew, si, tsi, normsi, fade, fadesi))
+        {
+            if (tnew > 0.)
+            {
+                vec4 tcol, tcolsi;
+                calcColor(ro, rd, normnew, tnew, bil_size, i, si, tsi, tcol, tcolsi);
+                if (tcol.a > 0.0)
+                {
+                    {
+                        vec3 tvalx = vec3(tnew, float(si), tsi);
+                        dx[i]=tvalx;
+                    }
+#ifdef DEBUG
+                    colx[i]=tcol;
+                    if (si)colxsi[i]=tcolsi;
+#else
+
+                    float dif = clamp(dot(normnew, l_dir), 0.0, 1.0);
+                    float amb = clamp(0.5 + 0.5 * dot(normnew, l_dir), 0.0, 1.0);
+
+                    {
+#ifdef USE_COLOR
+                        vec3 shad = 0.57 * color_blue * amb + 1.5*color_blue.bgr * dif;
+                        const vec3 tcr = color_red;
+#else
+                        vec3 shad = vec3(0.32, 0.43, 0.54) * amb + vec3(1.0, 0.9, 0.7) * dif;
+                        const vec3 tcr = vec3(1.,0.21,0.11);
+#endif
+                        float ta = clamp(length(tcol.rgb),0.,1.);
+                        tcol=clamp(tcol*tcol*2.,0.,1.);
+                        vec4 tvalx =
+                            vec4((tcol.rgb*shad*1.4 + 3.*(tcr*tcol.rgb)*clamp(1.-(amb+dif),0.,1.)), min(tcol.a,ta));
+                        tvalx.rgb=clamp(2.*tvalx.rgb*tvalx.rgb,0.,1.);
+                        tvalx*=(min(fade*5.,1.));
+                        colx[i]=tvalx;
+                    }
+                    if (si)
+                    {
+                        dif = clamp(dot(normsi, l_dir), 0.0, 1.0);
+                        amb = clamp(0.5 + 0.5 * dot(normsi, l_dir), 0.0, 1.0);
+                        {
+#ifdef USE_COLOR
+                            vec3 shad = 0.57 * color_blue * amb + 1.5*color_blue.bgr * dif;
+                            const vec3 tcr = color_red;
+#else
+                            vec3 shad = vec3(0.32, 0.43, 0.54) * amb + vec3(1.0, 0.9, 0.7) * dif;
+                            const vec3 tcr = vec3(1.,0.21,0.11);
+#endif
+                            float ta = clamp(length(tcolsi.rgb),0.,1.);
+                            tcolsi=clamp(tcolsi*tcolsi*2.,0.,1.);
+                            vec4 tvalx =
+                                vec4(tcolsi.rgb * shad + 3.*(tcr*tcolsi.rgb)*clamp(1.-(amb+dif),0.,1.), min(tcolsi.a,ta));
+                            tvalx.rgb=clamp(2.*tvalx.rgb*tvalx.rgb,0.,1.);
+                            tvalx.rgb*=(min(fadesi*5.,1.));
+                            colxsi[i]=tvalx;
+                        }
+                    }
+#endif
+                }
+            }
+        }
+    }
+    // transparency logic and layers sorting
+    float a = 1.;
+    if (dx[0].x < dx[1].x){{vec3 swap(dx[0], dx[1]);}{int swap(order[0], order[1]);}}
+    if (dx[1].x < dx[2].x){{vec3 swap(dx[1], dx[2]);}{int swap(order[1], order[2]);}}
+    if (dx[0].x < dx[1].x){{vec3 swap(dx[0], dx[1]);}{int swap(order[0], order[1]);}}
+
+    tout = max(max(dx[0].x, dx[1].x), dx[2].x);
+
+    if (dx[0].y < 0.5)
+    {
+        a=colx[order[0]].a;
+    }
+
+#if !(defined(DEBUG)&&defined(BUG))
+
+    // self intersection
+    bool [3] rul= bool[3](
+        ((dx[0].y > 0.5) && (dx[1].x <= 0.)),
+        ((dx[1].y > 0.5) && (dx[0].x > dx[1].z)),
+        ((dx[2].y > 0.5) && (dx[1].x > dx[2].z))
+    );
+    for(int k=0;k<3;k++){
+        if(rul[k]){
+            vec4 tcolxsi = vec4(0.);
+            tcolxsi=colxsi[order[k]];
+            vec4 tcolx = vec4(0.);
+            tcolx=colx[order[k]];
+
+            vec4 tvalx = mix(tcolxsi, tcolx, tcolx.a);
+            colx[order[k]]=tvalx;
+
+            vec4 tvalx2 = mix(vec4(0.), tvalx, max(tcolx.a, tcolxsi.a));
+            colx[order[k]]=tvalx2;
+        }
+    }
+
+#endif
+
+    float a1 = (dx[1].y < 0.5) ? colx[order[1]].a : ((dx[1].z > dx[0].x) ? colx[order[1]].a : 1.);
+    float a2 = (dx[2].y < 0.5) ? colx[order[2]].a : ((dx[2].z > dx[1].x) ? colx[order[2]].a : 1.);
+    col = mix(mix(colx[order[0]].rgb, colx[order[1]].rgb, a1), colx[order[2]].rgb, a2);
+    a = max(max(a, a1), a2);
+    return vec4(col, a);
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord)
+{
+    float osc = 0.5;
+    vec3 l_dir = normalize(vec3(0., 1., 0.));
+    l_dir *= rotz(0.5);
+    float mouseY = 1.0 * 0.5 * PI;
+    // Note: MOUSE_control disabled (no iMouse support)
+    // #ifdef MOUSE_control
+    // mouseY = (1.0 - 1.15 * iMouse.y / iResolution.y) * 0.5 * PI;
+    // if(iMouse.y < 1.)
+    // #endif
+#ifdef CAMERA_POS
+    mouseY = PI*CAMERA_POS;
+#else
+    mouseY = PI*0.49 - smoothstep(0.,8.5,mod((iTime+tshift)*0.33,25.))*(1.-smoothstep(14.,24.0,mod((iTime+tshift)*0.33,25.))) * 0.55 * PI;
+#endif
+#ifdef ROTATION_SPEED
+    float mouseX = -2.*PI-0.25*(iTime*ROTATION_SPEED+tshift);
+#else
+    float mouseX = -2.*PI-0.25*(iTime+tshift);
+#endif
+    // Note: MOUSE_control disabled (no iMouse support)
+    // #ifdef MOUSE_control
+    // mouseX+=-(iMouse.x / iResolution.x) * 2. * PI;
+    // #endif
+
+#ifdef CAMERA_FAR
+    vec3 eye = (2. + CAMERA_FAR) * vec3(cos(mouseX) * cos(mouseY), sin(mouseX) * cos(mouseY), sin(mouseY));
+#else
+    vec3 eye = 4. * vec3(cos(mouseX) * cos(mouseY), sin(mouseX) * cos(mouseY), sin(mouseY));
+#endif
+    vec3 w = normalize(-eye);
+    vec3 up = vec3(0., 0., 1.);
+    vec3 u = normalize(cross(w, up));
+    vec3 v = cross(u, w);
+
+    vec4 tot=vec4(0.);
+#if defined(AA_CUBE)||defined(AA_ALL)
+#ifdef AA_CUBE
+    const int AA = AA_CUBE;
+#else
+    const int AA = AA_ALL;
+#endif
+    vec3 incol_once=vec3(0.);
+    bool in_once=false;
+    vec4 incolbg_once=vec4(0.);
+    bool bg_in_once=false;
+    vec4 outcolbg_once=vec4(0.);
+    bool bg_out_once=false;
+    for( int mx=0; mx<AA; mx++ )
+    for( int nx=0; nx<AA; nx++ )
+    {
+    vec2 o = vec2(mod(float(mx+AA/2),float(AA)),mod(float(nx+AA/2),float(AA))) / float(AA) - 0.5;
+    vec2 uv = (fragCoord + o - 0.5 * iResolution.xy) / iResolution.x;
+#else
+    vec2 uv = (fragCoord - 0.5 * iResolution.xy) / iResolution.x;
+#endif
+    vec3 rd = normalize(w * FDIST + uv.x * u + uv.y * v);
+
+    vec3 ni;
+    float t = box(eye, rd, BOXDIMS, ni, true);
+    vec3 ro = eye + t * rd;
+    vec2 coords = ro.xy * ni.z/BOXDIMS.xy + ro.yz * ni.x/BOXDIMS.yz + ro.zx * ni.y/BOXDIMS.zx;
+    float fadeborders = (1.-smoothstep(0.915,1.05,abs(coords.x)))*(1.-smoothstep(0.915,1.05,abs(coords.y)));
+
+    if (t > 0.)
+    {
+        float ang = -iTime * 0.33;
+        vec3 col = vec3(0.);
+#ifdef AA_CUBE
+        if(in_once)col=incol_once;
+        else{
+        in_once=true;
+#endif
+        float R0 = (IOR - 1.) / (IOR + 1.);
+        R0 *= R0;
+
+        vec2 theta = vec2(0.);
+        vec3 n = vec3(cos(theta.x) * sin(theta.y), sin(theta.x) * sin(theta.y), cos(theta.y));
+
+        vec3 nr = n.zxy * ni.x + n.yzx * ni.y + n.xyz * ni.z;
+        vec3 rdr = reflect(rd, nr);
+        float talpha;
+        vec3 reflcol = background(ro, rdr, l_dir,talpha);
+
+        vec3 rd2 = refract(rd, nr, 1. / IOR);
+
+        float accum = 1.;
+        vec3 no2 = ni;
+        vec3 ro_refr = ro;
+
+        vec4 [2] colo = vec4[2](vec4(0.),vec4(0.));
+
+        for (int j = 0; j < 2 + ANGLE_loops; j++)
+        {
+            float tb;
+            vec2 coords2 = ro_refr.xy * no2.z + ro_refr.yz * no2.x + ro_refr.zx * no2.y;
+            vec3 eye2 = vec3(coords2, -1.);
+            vec3 rd2trans = rd2.yzx * no2.x + rd2.zxy * no2.y + rd2.xyz * no2.z;
+
+            rd2trans.z = -rd2trans.z;
+            vec4 internalcol = insides(eye2, rd2trans, no2, l_dir, tb);
+            if (tb > 0.)
+            {
+                internalcol.rgb *= accum;
+                colo[j]=internalcol;
+            }
+
+            if ((tb <= 0.) || (internalcol.a < 1.))
+            {
+                float tout = box(ro_refr, rd2, BOXDIMS, no2, false);
+                no2 = n.zyx * no2.x + n.xzy * no2.y + n.yxz * no2.z;
+                vec3 rout = ro_refr + tout * rd2;
+                vec3 rdout = refract(rd2, -no2, IOR);
+                float fresnel2 = R0 + (1. - R0) * pow(1. - dot(rdout, no2), 1.3);
+                rd2 = reflect(rd2, -no2);
+
+#ifdef backside_refl
+                if((dot(rdout, no2))>0.5){fresnel2=1.;}
+#endif
+                ro_refr = rout;
+                ro_refr.z = max(ro_refr.z, -0.999);
+
+                accum *= fresnel2;
+            }
+        }
+        float fresnel = R0 + (1. - R0) * pow(1. - dot(-rd, nr), 5.);
+        col = mix(mix(colo[1].rgb * colo[1].a, colo[0].rgb, colo[0].a)*fadeborders, reflcol, pow(fresnel, 1.5));
+        col=clamp(col,0.,1.);
+#ifdef AA_CUBE
+        }
+        incol_once=col;
+        if(!bg_in_once){
+        bg_in_once=true;
+        float alpha;
+        incolbg_once = vec4(background(eye, rd, l_dir, alpha), 0.15);
+#if defined(BG_ALPHA)||defined(ONLY_BOX)||defined(SHADOW_ALPHA)
+        incolbg_once.w = alpha;
+#endif
+        }
+#endif
+
+        float cineshader_alpha = 0.;
+        cineshader_alpha = clamp(0.15*dot(eye,ro),0.,1.);
+        vec4 tcolx = vec4(col, cineshader_alpha);
+#if defined(BG_ALPHA)||defined(ONLY_BOX)||defined(SHADOW_ALPHA)
+        tcolx.w = 1.;
+#endif
+        tot += tcolx;
+    }
+    else
+    {
+        vec4 tcolx = vec4(0.);
+#ifdef AA_CUBE
+        if(!bg_out_once){
+        bg_out_once=true;
+#endif
+        float alpha;
+        tcolx = vec4(background(eye, rd, l_dir, alpha), 0.15);
+#if defined(BG_ALPHA)||defined(ONLY_BOX)||defined(SHADOW_ALPHA)
+        tcolx.w = alpha;
+#endif
+#ifdef AA_CUBE
+        outcolbg_once=tcolx;
+        }else tcolx=max(outcolbg_once,incolbg_once);
+#endif
+        tot += tcolx;
+    }
+#if defined(AA_CUBE)||defined(AA_ALL)
+    }
+    tot /= float(AA*AA);
+#endif
+    fragColor = tot;
+#ifdef NO_ALPHA
+    fragColor.w = 1.;
+#endif
+    fragColor.rgb=clamp(fragColor.rgb,0.,1.);
+    // Note: iChannel0 line removed (texture channel not supported)
+    // Original line was for optional background blending when BG_ALPHA/ONLY_BOX/SHADOW_ALPHA defined
+    // #if defined(BG_ALPHA)||defined(ONLY_BOX)||defined(SHADOW_ALPHA)
+    // fragColor.rgb=fragColor.rgb*fragColor.w+texture(iChannel0, fragCoord/iResolution.xy).rgb*(1.-fragColor.w);
+    // #endif
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}

shaders/cube_lines/meta.txt

@@ -0,0 +1,2 @@
+Name: Cube lines
+Author: Danil

shaders/dbz/dbz.frag.msl

@@ -0,0 +1,127 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// New Leaked 3I/Atlas NASA Footage — msm01
+// MSL port of dbz.vk.glsl.
+
+struct ShadertoyUBO {
+    float iTime;
+    float2 iResolution;
+};
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+constant float NBCaps = 3.0;
+
+static float2x2 r2d(float a) {
+    float c = cos(a), s = sin(a);
+    return float2x2(c, s, -s, c);
+}
+
+static float hash12(float2 p) {
+    float3 p3 = fract(float3(p.xyx) * 0.1031);
+    p3 += dot(p3, p3.yzx + 33.33);
+    return fract((p3.x + p3.y) * p3.z);
+}
+
+static float fbm(float2 v_p) {
+    float pvpx = v_p.x;
+    float2 V1 = float2(floor(pvpx));
+    float2 V2 = float2(floor(pvpx + 1.0));
+    return mix(hash12(V1), hash12(V2), smoothstep(0.0, 1.0, fract(pvpx)));
+}
+
+#define S(a,b,c) smoothstep(a,b,c)
+
+fragment float4 dbz_fs(PassthroughVOut in [[stage_in]],
+                       constant ShadertoyUBO& U [[buffer(0)]]) {
+    float2 fragCoord = in.uv * U.iResolution;
+    float2 p = float2((1.0 / U.iResolution.y) * (fragCoord.x - U.iResolution.x / 2.0),
+                      fragCoord.y / U.iResolution.y - 0.5);
+
+    p.x = -p.x;
+    p *= 150.0;
+
+    float4 col = float4(0.05, 0.05, 0.15, 1.0);
+
+    float2 save1 = p;
+
+    p = p * r2d(-0.05);
+    col = mix(col, float4(0.2, 0.3, 0.5, 1.0),
+              smoothstep(75.0, 0.0, abs(p.y - 5.0 * fbm(float2(0.01 * (p.x - 33.333 * U.iTime))) + 3.5)));
+    p = p * r2d(0.05);
+
+    p = p * r2d(-0.05);
+    p *= 0.35;
+    p += float2(-5.0 * U.iTime, 0.0);
+
+    float2 b = fract(5.0 * p);
+    p = floor(5.0 * p);
+    if (fbm(float2(p.x * p.y)) > 0.996) {
+        col += clamp(1.0 - pow(3.0 * length(b + float2(-0.5)), 0.5), 0.0, 1.0);
+    }
+
+    p = save1;
+    float2 save3;
+
+    float Nb_Capsules = clamp(NBCaps, 0.0, 4.0);
+    for (float i = 0.0; i < Nb_Capsules; i++) {
+        p = save1;
+        p = p * r2d(-0.05);
+        p *= 2.5;
+        p *= 1.0 - 0.25 * i;
+        p += float2(150.0 * fbm(float2(0.15 * U.iTime + i * 54.321)) - 75.0,
+                    50.0 * sin(0.25 * U.iTime + i * 54.321) - 25.0);
+        save3 = p;
+
+        p *= 0.04;
+        p.y = abs(p.y);
+
+        if (p.x > 0.0) {
+            col += float4(0.0, 1.0, 0.5, 1.0) * smoothstep(0.2, 0.0, abs(p.y - 0.05 * fbm(float2(1.5 * p.x - 40.0 * U.iTime))) - 0.05) * smoothstep(29.0, 0.0, abs(p.x));
+            col += float4(1.0, 1.0, 1.0, 1.0) * smoothstep(0.1, 0.0, abs(p.y - 0.05 * fbm(float2(1.5 * p.x - 40.0 * U.iTime))) - 0.05) * smoothstep(29.0, 0.0, abs(p.x));
+        }
+
+        p = save3;
+        p.y = abs(p.y);
+        p += float2(-10.0, 0.0);
+        p *= float2(0.75, 1.0);
+
+        col += 0.8 * float4(0.0, 1.0, 0.5, 1.0) * S(20.0, 0.0, length(p) - 25.0 + 7.0 * sin(0.30 * length(p) * atan2(p.y, p.x) + 55.0 * U.iTime));
+        col += 0.8 * float4(1.0, 1.0, 1.0, 1.0) * S(20.0, 0.0, length(p) - 20.0 + 7.0 * sin(0.30 * length(p) * atan2(p.y, p.x) + 55.0 * U.iTime));
+
+        p = save3;
+
+        col = mix(col, float4(1.0), 0.5 * S(10.0, 0.0, length(p + float2(5.0, 0.0)) - 20.0) * abs(sin(50.0 * U.iTime)));
+        col = mix(col, float4(1.0), 0.5 * S(20.0, 0.0, length(p + float2(5.0, 0.0)) - 20.0));
+        col = mix(col, float4(1.0), S(0.01, 0.0, length(p) - 20.0));
+
+        if (length(p) - 20.0 < 0.0) {
+            col = mix(col, float4(0.65, 0.68, 0.68 + 0.1 * (3.0 - i), 1.0), S(0.5, 0.0, length(p - float2(2.0, 0.0)) - 17.0));
+            if (S(0.0, 1.0, length(float2(3.0, 2.0) * p + float2(33.5, 0.0)) - 23.0) > 0.0) {
+                col = mix(col, float4(0.45, 0.55, 0.55 + 0.1 * (3.0 - i), 1.0),
+                          0.75 * S(0.5, 0.0, length(p - float2(2.0, 0.0) + 0.5 * fbm(float2(4.5 * atan2(p.y, p.x)))) - 9.0));
+            }
+
+            col = mix(col, float4(0.0), S(0.2, 0.0, abs(length(p) - 19.9) - 0.20));
+            col = mix(col, float4(0.5, 0.2, 0.3, 1.0)
+                          - S(5.0, 0.0, length(p + float2(-6.0, 15.0)) - 20.0)
+                          - S(0.25, 0.0, abs(length(p + float2(0.0, 3.0)) - 15.0) - 0.4)
+                          - S(0.0, 1.5, p.y - 8.5)
+                          + 0.25 * float4(1.0, 0.5, 0.0, 1.0) * S(10.0, 0.0, abs(p.y))
+                          ,
+                          S(0.5, 0.0, length(float2(3.0, 2.0) * p + float2(35.0, 0.0)) - 19.9));
+
+            col = mix(col, float4(0.0, 0.0, 0.0, 1.0), S(1.0, 0.0, abs(length(float2(3.0, 2.0) * p + float2(35.0, 0.0)) - 19.9) - 0.1));
+            col = mix(col, float4(0.0, 0.0, 0.0, 1.0), S(1.0, 0.0, abs(length(float2(3.0, 2.0) * p + float2(33.5, 0.0)) - 23.0) - 0.1));
+
+            if (p.y > 0.0) col = mix(col, float4(0.0, 0.0, 0.0, 1.0), S(1.0, 0.0, abs(length(float2(3.0, 2.0) * p + float2(29.0, 0.0)) - 30.0) - 0.1));
+            if (p.y < 0.0) col = mix(col, float4(0.0, 0.0, 0.0, 1.0), S(1.0, 0.0, abs(length(float2(3.0, 2.0) * p + float2(-31.0, 0.0)) - 30.0) - 0.1));
+        }
+    }
+
+    return clamp(col, 0.0, 1.0);
+}

shaders/dbz/dbz.vk.glsl

@@ -0,0 +1,127 @@
+#version 450
+
+// Name: New Leaked 3I/Atlas NASA Footage
+// Author: msm01
+// URL: https://www.shadertoy.com/view/3ftcRr
+
+layout(location = 0) in  vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+
+layout(set = 3, binding = 0) uniform ShadertoyUBO {
+    float iTime;
+    vec2  iResolution;
+};
+
+#define s(a,b,c) smoothstep(a,b,c)
+#define PI     3.14159
+#define NBCaps 3.
+
+mat2 r2d(float a) { float c = cos(a), s = sin(a); return mat2(c, s, -s, c); }
+float metaDiamond(vec2 p, vec2 pixel, float r) { vec2 d = abs(p - pixel); return r / (d.x + d.y); }
+
+float hash12(vec2 p) {
+    vec3 p3 = fract(vec3(p.xyx) * .1031);
+    p3 += dot(p3, p3.yzx + 33.33);
+    return fract((p3.x + p3.y) * p3.z);
+}
+
+float fbm(in vec2 v_p) {
+    float pvpx = v_p.x;
+    vec2 V1 = vec2(floor(pvpx));
+    vec2 V2 = vec2(floor(pvpx + 1.0));
+    return mix(hash12(V1), hash12(V2), smoothstep(0.0, 1.0, fract(pvpx)));
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord) {
+    vec2 p = vec2((1.0 / iResolution.y) * (fragCoord.x - iResolution.x / 2.0),
+                  fragCoord.y / iResolution.y - 0.5);
+
+    p.x = -p.x;
+    p *= 150.0;
+
+    vec4 col = vec4(0.05, 0.05, 0.15, 1.0);
+
+    vec2 save1 = p;
+    vec2 save2 = p;
+
+    p *= r2d(-0.05);
+    col = mix(col, vec4(0.2, 0.3, 0.5, 1.0),
+              smoothstep(75.0, 0.0, abs(p.y - 5.0 * fbm(vec2(0.01 * (p.x - 33.333 * iTime))) + 3.5)));
+    p *= r2d(0.05);
+
+    p *= r2d(-0.05);
+    p *= 0.35;
+    p += vec2(-5.0 * iTime, 0.0);
+
+    vec2 b = fract(5.0 * p);
+    p = floor(5.0 * p);
+    if (fbm(vec2(p.x * p.y)) > 0.996) col += clamp(1.0 - pow(3.0 * length(b + vec2(-0.5)), 0.5), 0.0, 1.0);
+
+    p = save1;
+    vec2 save3;
+
+    float Nb_Capsules = clamp(NBCaps, 0.0, 4.0);
+    for (float i = 0.0; i < Nb_Capsules; i++) {
+        p = save1;
+        p *= r2d(-0.05);
+        p *= 2.5;
+        p *= 1.0 - 0.25 * i;
+        p += vec2(150.0 * fbm(vec2(0.15 * iTime + i * 54.321)) - 75.0,
+                  50.0 * sin(0.25 * iTime + i * 54.321) - 25.0);
+        save3 = p;
+
+        p *= 0.04;
+        p.y = abs(p.y);
+
+        if (p.x > 0.0) {
+            col += vec4(0.0, 1.0, 0.5, 1.0) * smoothstep(0.2, 0.0, abs(p.y - 0.05 * fbm(vec2(1.5 * p.x - 40.0 * iTime))) - 0.05) * smoothstep(29.0, 0.0, abs(p.x));
+            col += vec4(1.0, 1.0, 1.0, 1.0) * smoothstep(0.1, 0.0, abs(p.y - 0.05 * fbm(vec2(1.5 * p.x - 40.0 * iTime))) - 0.05) * smoothstep(29.0, 0.0, abs(p.x));
+        }
+
+        p = save3;
+        p.y = abs(p.y);
+        p += vec2(-10.0, 0.0);
+        p *= vec2(0.75, 1.0);
+
+        col += 0.8 * vec4(0.0, 1.0, 0.5, 1.0) * s(20.0, 0.0, length(p) - 25.0 + 7.0 * sin(0.30 * length(p) * atan(p.y, p.x) + 55.0 * iTime));
+        col += 0.8 * vec4(1.0, 1.0, 1.0, 1.0) * s(20.0, 0.0, length(p) - 20.0 + 7.0 * sin(0.30 * length(p) * atan(p.y, p.x) + 55.0 * iTime));
+
+        p = save3;
+
+        col = mix(col, vec4(1.0), 0.5 * s(10.0, 0.0, length(p + vec2(5.0, 0.0)) - 20.0) * abs(sin(50.0 * iTime)));
+        col = mix(col, vec4(1.0), 0.5 * s(20.0, 0.0, length(p + vec2(5.0, 0.0)) - 20.0));
+
+        col = mix(col, vec4(1.0), s(0.01, 0.0, length(p) - 20.0));
+
+        if (length(p) - 20.0 < 0.0) {
+            col = mix(col, vec4(0.65, 0.68, 0.68 + 0.1 * (3.0 - i), 1.0), s(0.5, 0.0, length(p - vec2(2.0, 0.0)) - 17.0));
+            if (s(0.0, 1.0, length(vec2(3.0, 2.0) * p + vec2(33.5, 0.0)) - 23.0) > 0.0)
+                col = mix(col, vec4(0.45, 0.55, 0.55 + 0.1 * (3.0 - i), 1.0),
+                          0.75 * s(0.5, 0.0, length(p - vec2(2.0, 0.0) + 0.5 * fbm(vec2(4.5 * atan(p.y, p.x)))) - 9.0));
+
+            col = mix(col, vec4(0.0), s(0.2, 0.0, abs(length(p) - 19.9) - 0.20));
+            col = mix(col, vec4(0.5, 0.2, 0.3, 1.0)
+                          - s(5.0, 0.0, length(p + vec2(-6.0, 15.0)) - 20.0)
+                          - s(0.25, 0.0, abs(length(p + vec2(0.0, 3.0)) - 15.0) - 0.4)
+                          - s(0.0, 1.5, p.y - 8.5)
+                          + 0.25 * vec4(1.0, 0.5, 0.0, 1.0) * s(10.0, 0.0, abs(p.y))
+                          ,
+                          s(0.5, 0.0, length(vec2(3.0, 2.0) * p + vec2(35.0, 0.0)) - 19.9));
+
+            col = mix(col, vec4(0.0, 0.0, 0.0, 1.0), s(1.0, 0.0, abs(length(vec2(3.0, 2.0) * p + vec2(35.0, 0.0)) - 19.9) - 0.1));
+            col = mix(col, vec4(0.0, 0.0, 0.0, 1.0), s(1.0, 0.0, abs(length(vec2(3.0, 2.0) * p + vec2(33.5, 0.0)) - 23.0) - 0.1));
+
+            if (p.y > 0.0) col = mix(col, vec4(0.0, 0.0, 0.0, 1.0), s(1.0, 0.0, abs(length(vec2(3.0, 2.0) * p + vec2(29.0, 0.0)) - 30.0) - 0.1));
+            if (p.y < 0.0) col = mix(col, vec4(0.0, 0.0, 0.0, 1.0), s(1.0, 0.0, abs(length(vec2(3.0, 2.0) * p + vec2(-31.0, 0.0)) - 30.0) - 0.1));
+        }
+    }
+
+    fragColor = clamp(col, 0.0, 1.0);
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}

shaders/dbz/meta.txt

@@ -0,0 +1,2 @@
+Name: New Leaked 3I/Atlas NASA Footage
+Author: msm01

shaders/fractal_pyramid/fractal_pyramid.frag.msl

@@ -0,0 +1,67 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// Fractal Pyramid — bradjamesgrant
+// MSL port of fractal_pyramid.vk.glsl.
+
+struct ShadertoyUBO {
+    float iTime;
+    float2 iResolution;
+};
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+static float3 palette(float d) {
+    return mix(float3(0.2, 0.7, 0.9), float3(1.0, 0.0, 1.0), d);
+}
+
+static float2 rotate(float2 p, float a) {
+    float c = cos(a);
+    float s = sin(a);
+    return p * float2x2(c, s, -s, c);
+}
+
+static float mapScene(float3 p, float iTime) {
+    for (int i = 0; i < 8; ++i) {
+        float t = iTime * 0.2;
+        p.xz = rotate(p.xz, t);
+        p.xy = rotate(p.xy, t * 1.89);
+        p.xz = abs(p.xz);
+        p.xz -= 0.5;
+    }
+    return dot(sign(p), p) / 5.0;
+}
+
+static float4 rm(float3 ro, float3 rd, float iTime) {
+    float t = 0.0;
+    float3 col = float3(0.0);
+    float d = 1.0;
+    for (int i = 0; i < 64; ++i) {
+        float3 p = ro + rd * t;
+        d = mapScene(p, iTime) * 0.5;
+        if (d < 0.02) break;
+        if (d > 100.0) break;
+        col += palette(length(p) * 0.1) / (400.0 * d);
+        t += d;
+    }
+    return float4(col, 1.0 / (d * 100.0));
+}
+
+fragment float4 fractal_pyramid_fs(PassthroughVOut in [[stage_in]],
+                                    constant ShadertoyUBO& U [[buffer(0)]]) {
+    float2 fragCoord = in.uv * U.iResolution;
+    float2 uv = (fragCoord - (U.iResolution * 0.5)) / U.iResolution.x;
+    float3 ro = float3(0.0, 0.0, -50.0);
+    ro.xz = rotate(ro.xz, U.iTime);
+    float3 cf = normalize(-ro);
+    float3 cs = normalize(cross(cf, float3(0.0, 1.0, 0.0)));
+    float3 cu = normalize(cross(cf, cs));
+
+    float3 uuv = ro + cf * 3.0 + uv.x * cs + uv.y * cu;
+    float3 rd = normalize(uuv - ro);
+
+    return rm(ro, rd, U.iTime);
+}

shaders/fractal_pyramid/fractal_pyramid.vk.glsl

@@ -0,0 +1,71 @@
+#version 450
+
+// Name: Fractal Pyramid
+// Author: bradjamesgrant
+// URL: https://www.shadertoy.com/view/tsXBzS
+
+layout(location = 0) in  vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+
+layout(set = 3, binding = 0) uniform ShadertoyUBO {
+    float iTime;
+    vec2  iResolution;
+};
+
+vec3 palette(float d) {
+    return mix(vec3(0.2, 0.7, 0.9), vec3(1.0, 0.0, 1.0), d);
+}
+
+vec2 rotate(vec2 p, float a) {
+    float c = cos(a);
+    float s = sin(a);
+    return p * mat2(c, s, -s, c);
+}
+
+float mapScene(vec3 p) {
+    for (int i = 0; i < 8; ++i) {
+        float t = iTime * 0.2;
+        p.xz = rotate(p.xz, t);
+        p.xy = rotate(p.xy, t * 1.89);
+        p.xz = abs(p.xz);
+        p.xz -= 0.5;
+    }
+    return dot(sign(p), p) / 5.0;
+}
+
+vec4 rm(vec3 ro, vec3 rd) {
+    float t = 0.0;
+    vec3 col = vec3(0.0);
+    float d = 1.0;
+    for (int i = 0; i < 64; ++i) {
+        vec3 p = ro + rd * t;
+        d = mapScene(p) * 0.5;
+        if (d < 0.02) break;
+        if (d > 100.0) break;
+        col += palette(length(p) * 0.1) / (400.0 * d);
+        t += d;
+    }
+    return vec4(col, 1.0 / (d * 100.0));
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord) {
+    vec2 uv = (fragCoord - (iResolution.xy * 0.5)) / iResolution.x;
+    vec3 ro = vec3(0.0, 0.0, -50.0);
+    ro.xz = rotate(ro.xz, iTime);
+    vec3 cf = normalize(-ro);
+    vec3 cs = normalize(cross(cf, vec3(0.0, 1.0, 0.0)));
+    vec3 cu = normalize(cross(cf, cs));
+
+    vec3 uuv = ro + cf * 3.0 + uv.x * cs + uv.y * cu;
+    vec3 rd = normalize(uuv - ro);
+
+    vec4 col = rm(ro, rd);
+    fragColor = col;
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}

shaders/fractal_pyramid/meta.txt

@@ -0,0 +1,2 @@
+Name: Fractal Pyramid
+Author: bradjamesgrant

shaders/just_another_cube/just_another_cube.frag.msl

@@ -0,0 +1,89 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// Just Another Cube — mrange
+// MSL port of just_another_cube.vk.glsl. The Shadertoy original uses
+// mutable file-scope globals; in MSL we pass them by reference.
+
+struct ShadertoyUBO {
+    float iTime;
+    float2 iResolution;
+};
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+constant float M = 1e-3;
+
+static float D(float3 p,
+               thread float2x2& R,
+               thread float& d,
+               thread float& G) {
+    p.xy = p.xy * R;
+    p.xz = p.xz * R;
+
+    float3 S = sin(123.0 * p);
+
+    float shell = abs(length(p) - 0.6);
+    p *= p * p * p;
+    d = pow(dot(p, p), 0.125) - 0.5
+        - pow(1.0 + S.x * S.y * S.z, 8.0) / 1e5;
+
+    G = min(G, max(shell, d));
+
+    return d;
+}
+
+fragment float4 just_another_cube_fs(PassthroughVOut in [[stage_in]],
+                                      constant ShadertoyUBO& U [[buffer(0)]]) {
+    float2 C = in.uv * U.iResolution;
+
+    float2x2 R;
+    float d = 1.0, z = 0.0, G = 9.0;
+
+    float3 r = float3(U.iResolution, U.iResolution.y);
+    float3 I = normalize(float3(C - 0.5 * r.xy, r.y));
+    float3 B = float3(1, 2, 9) * M;
+    float3 p = float3(0.0);
+    float3 O = float3(0.0);
+
+    {
+        float4 cs = cos(0.3 * U.iTime + float4(0, 11, 33, 0));
+        R = float2x2(cs.x, cs.y, cs.z, cs.w);
+    }
+
+    for (; z < 9.0 && d > M; z += D(p, R, d, G)) {
+        p = z * I;
+        p.z -= 2.0;
+    }
+
+    if (z < 9.0) {
+        for (int i = 0; i < 3; ) {
+            r = float3(0.0);
+            r[i] = M;
+            O[i++] = D(p + r, R, d, G) - D(p - r, R, d, G);
+        }
+
+        O = normalize(O);
+        z = 1.0 + dot(O, I);
+
+        r = reflect(I, O);
+
+        C = (p + r * (5.0 - p.y) / abs(r.y)).xz;
+
+        float3 colorTerm;
+        if (r.y > 0.0) {
+            d = sqrt(length(C * C)) + 1.0;
+            colorTerm = 5e2 * smoothstep(5.0, 4.0, d) * d * B;
+        } else {
+            colorTerm = exp(-2.0 * length(C)) * (B / M - 1.0);
+        }
+
+        O = z * z * colorTerm + pow(1.0 + O.y, 5.0) * B;
+    }
+
+    float4 result = sqrt(float4(O + B / G, O.x + B.x / G));
+    return result;
+}

shaders/just_another_cube/just_another_cube.vk.glsl

@@ -0,0 +1,88 @@
+#version 450
+
+// Name: Just Another Cube
+// Author: mrange
+// URL: https://www.shadertoy.com/view/3XdXRr
+// CC0: Just another cube
+
+layout(location = 0) in  vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+
+layout(set = 3, binding = 0) uniform ShadertoyUBO {
+    float iTime;
+    vec2  iResolution;
+};
+
+mat2 R;
+float d = 1.;
+float z = 0.;
+float G = 9.;
+float M = 1e-3;
+
+float D(vec3 p) {
+    p.xy *= R;
+    p.xz *= R;
+
+    vec3 S = sin(123. * p);
+
+    G = min(
+        G,
+        max(
+            abs(length(p) - .6),
+            d = pow(dot(p *= p * p * p, p), .125) - .5
+                - pow(1. + S.x * S.y * S.z, 8.) / 1e5
+        )
+    );
+
+    return d;
+}
+
+void mainImage(out vec4 o, vec2 C) {
+    vec3 p,
+         O,
+         r = vec3(iResolution.xy, iResolution.y),
+         I = normalize(vec3(C - .5 * r.xy, r.y)),
+         B = vec3(1, 2, 9) * M;
+
+    for (
+        R = mat2(cos(.3 * iTime + vec4(0, 11, 33, 0)));
+        z < 9. && d > M;
+        z += D(p)
+    )
+        p = z * I,
+        p.z -= 2.;
+
+    O = vec3(0.0);
+
+    if (z < 9.) {
+        for (int i = 0; i < 3; ) {
+            r -= r;
+            r[i] = M;
+            O[i++] = D(p + r) - D(p - r);
+        }
+
+        z = 1. + dot(O = normalize(O), I);
+
+        r = reflect(I, O);
+
+        C = (p + r * (5. - p.y) / abs(r.y)).xz;
+
+        O =
+            z * z *
+            (
+                r.y > 0.
+                ? 5e2 * smoothstep(5., 4., d = sqrt(length(C * C)) + 1.) * d * B
+                : exp(-2. * length(C)) * (B / M - 1.)
+            )
+            + pow(1. + O.y, 5.) * B;
+    }
+
+    o = sqrt(O + B / G).xyzx;
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}

shaders/just_another_cube/meta.txt

@@ -0,0 +1,2 @@
+Name: Just Another Cube
+Author: mrange

shaders/octograms/meta.txt

@@ -0,0 +1,2 @@
+Name: Octograms
+Author: whisky_shusuky

shaders/octograms/octograms.frag.msl

@@ -0,0 +1,95 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// Octograms — whisky_shusuky
+// MSL port of octograms.vk.glsl. The Shadertoy original uses a mutable
+// file-scope `gTime`; in MSL we pass it as a parameter through the chain.
+
+struct ShadertoyUBO {
+    float iTime;
+    float2 iResolution;
+};
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+static float2x2 rot(float a) {
+    float c = cos(a), s = sin(a);
+    return float2x2(c, s, -s, c);
+}
+
+static float sdBox(float3 p, float3 b) {
+    float3 q = abs(p) - b;
+    return length(max(q, float3(0.0))) + min(max(q.x, max(q.y, q.z)), 0.0);
+}
+
+static float boxGeom(float3 pos, float scale) {
+    pos *= scale;
+    float base = sdBox(pos, float3(0.4, 0.4, 0.1)) / 1.5;
+    pos.xy = (pos.xy * 5.0 - float2(0.0, 3.5)) * rot(0.75);
+    return -base;
+}
+
+static float box_set(float3 pos, float gTime) {
+    float3 pos_origin = pos;
+
+    pos = pos_origin;
+    pos.y += sin(gTime * 0.4) * 2.5;
+    pos.xy = pos.xy * rot(0.8);
+    float box1 = boxGeom(pos, 2.0 - abs(sin(gTime * 0.4)) * 1.5);
+
+    pos = pos_origin;
+    pos.y -= sin(gTime * 0.4) * 2.5;
+    pos.xy = pos.xy * rot(0.8);
+    float box2 = boxGeom(pos, 2.0 - abs(sin(gTime * 0.4)) * 1.5);
+
+    pos = pos_origin;
+    pos.x += sin(gTime * 0.4) * 2.5;
+    pos.xy = pos.xy * rot(0.8);
+    float box3 = boxGeom(pos, 2.0 - abs(sin(gTime * 0.4)) * 1.5);
+
+    pos = pos_origin;
+    pos.x -= sin(gTime * 0.4) * 2.5;
+    pos.xy = pos.xy * rot(0.8);
+    float box4 = boxGeom(pos, 2.0 - abs(sin(gTime * 0.4)) * 1.5);
+
+    pos = pos_origin;
+    pos.xy = pos.xy * rot(0.8);
+    float box5 = boxGeom(pos, 0.5) * 6.0;
+
+    pos = pos_origin;
+    float box6 = boxGeom(pos, 0.5) * 6.0;
+
+    return max(max(max(max(max(box1, box2), box3), box4), box5), box6);
+}
+
+fragment float4 octograms_fs(PassthroughVOut in [[stage_in]],
+                              constant ShadertoyUBO& U [[buffer(0)]]) {
+    float2 fragCoord = in.uv * U.iResolution;
+    float2 p = (fragCoord * 2.0 - U.iResolution) / min(U.iResolution.x, U.iResolution.y);
+
+    float3 ro = float3(0.0, -0.2, U.iTime * 4.0);
+    float3 ray = normalize(float3(p, 1.5));
+    ray.xy = ray.xy * rot(sin(U.iTime * 0.03) * 5.0);
+    ray.yz = ray.yz * rot(sin(U.iTime * 0.05) * 0.2);
+    float t = 0.1;
+    float ac = 0.0;
+
+    for (int i = 0; i < 99; i++) {
+        float3 pos = ro + ray * t;
+        pos = fract((pos - 2.0) / 4.0) * 4.0 - 2.0;
+        float gTime = U.iTime - float(i) * 0.01;
+
+        float d = box_set(pos, gTime);
+        d = max(abs(d), 0.01);
+        ac += exp(-d * 23.0);
+        t += d * 0.55;
+    }
+
+    float3 col = float3(ac * 0.02);
+    col += float3(0.0, 0.2 * abs(sin(U.iTime)), 0.5 + sin(U.iTime) * 0.2);
+
+    return float4(col, 1.0 - t * (0.02 + 0.02 * sin(U.iTime)));
+}

shaders/octograms/octograms.vk.glsl

@@ -0,0 +1,109 @@
+#version 450
+
+// Name: Octograms
+// Author: whisky_shusuky
+// URL: https://www.shadertoy.com/view/tlVGDt
+
+layout(location = 0) in  vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+
+layout(set = 3, binding = 0) uniform ShadertoyUBO {
+    float iTime;
+    vec2  iResolution;
+};
+
+float gTime = 0.0;
+const float REPEAT = 5.0;
+
+mat2 rot(float a) {
+    float c = cos(a), s = sin(a);
+    return mat2(c, s, -s, c);
+}
+
+float sdBox(vec3 p, vec3 b) {
+    vec3 q = abs(p) - b;
+    return length(max(q, vec3(0.0))) + min(max(q.x, max(q.y, q.z)), 0.0);
+}
+
+float boxGeom(vec3 pos, float scale) {
+    pos *= scale;
+    float base = sdBox(pos, vec3(.4, .4, .1)) / 1.5;
+    pos.xy *= 5.0;
+    pos.y -= 3.5;
+    pos.xy *= rot(.75);
+    float result = -base;
+    return result;
+}
+
+float box_set(vec3 pos, float iTimeLocal) {
+    vec3 pos_origin = pos;
+    pos = pos_origin;
+    pos.y += sin(gTime * 0.4) * 2.5;
+    pos.xy *= rot(.8);
+    float box1 = boxGeom(pos, 2.0 - abs(sin(gTime * 0.4)) * 1.5);
+
+    pos = pos_origin;
+    pos.y -= sin(gTime * 0.4) * 2.5;
+    pos.xy *= rot(.8);
+    float box2 = boxGeom(pos, 2.0 - abs(sin(gTime * 0.4)) * 1.5);
+
+    pos = pos_origin;
+    pos.x += sin(gTime * 0.4) * 2.5;
+    pos.xy *= rot(.8);
+    float box3 = boxGeom(pos, 2.0 - abs(sin(gTime * 0.4)) * 1.5);
+
+    pos = pos_origin;
+    pos.x -= sin(gTime * 0.4) * 2.5;
+    pos.xy *= rot(.8);
+    float box4 = boxGeom(pos, 2.0 - abs(sin(gTime * 0.4)) * 1.5);
+
+    pos = pos_origin;
+    pos.xy *= rot(.8);
+    float box5 = boxGeom(pos, .5) * 6.0;
+
+    pos = pos_origin;
+    float box6 = boxGeom(pos, .5) * 6.0;
+
+    float result = max(max(max(max(max(box1, box2), box3), box4), box5), box6);
+    return result;
+}
+
+float mapScene(vec3 pos, float iTimeLocal) {
+    return box_set(pos, iTimeLocal);
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord) {
+    vec2 p = (fragCoord.xy * 2.0 - iResolution.xy) / min(iResolution.x, iResolution.y);
+    vec3 ro = vec3(0.0, -0.2, iTime * 4.0);
+    vec3 ray = normalize(vec3(p, 1.5));
+    ray.xy = ray.xy * rot(sin(iTime * .03) * 5.0);
+    ray.yz = ray.yz * rot(sin(iTime * .05) * .2);
+    float t = 0.1;
+    vec3 col = vec3(0.0);
+    float ac = 0.0;
+
+    for (int i = 0; i < 99; i++) {
+        vec3 pos = ro + ray * t;
+        pos = mod(pos - 2.0, 4.0) - 2.0;
+        gTime = iTime - float(i) * 0.01;
+
+        float d = mapScene(pos, iTime);
+
+        d = max(abs(d), 0.01);
+        ac += exp(-d * 23.0);
+
+        t += d * 0.55;
+    }
+
+    col = vec3(ac * 0.02);
+    col += vec3(0.0, 0.2 * abs(sin(iTime)), 0.5 + sin(iTime) * 0.2);
+
+    fragColor = vec4(col, 1.0 - t * (0.02 + 0.02 * sin(iTime)));
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}

shaders/remember/meta.txt

@@ -0,0 +1,2 @@
+Name: Remember
+Author: diatribes

shaders/remember/remember.frag.msl

@@ -0,0 +1,64 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// Remember — diatribes
+// MSL port of remember.vk.glsl.
+
+struct ShadertoyUBO {
+    float iTime;
+    float2 iResolution;
+};
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+static float hash12(float2 p) {
+    float3 p3 = fract(float3(p.xyx) * 0.1031);
+    p3 += dot(p3, p3.yzx + 33.33);
+    return fract((p3.x + p3.y) * p3.z);
+}
+
+fragment float4 remember_fs(PassthroughVOut in [[stage_in]],
+                            constant ShadertoyUBO& U [[buffer(0)]]) {
+    float2 fragCoord = in.uv * U.iResolution;
+    float2 u = fragCoord;
+
+    float3 q, p = float3(U.iResolution, U.iResolution.x / U.iResolution.y);
+
+    float i = 0.0, s = 0.0;
+    float d = 0.125 * hash12(u);
+    float t = U.iTime * 0.1;
+
+    u = (u + u - p.xy) / p.y;
+    if (abs(u.y) > 0.8) { return float4(0); }
+
+    float4 o = float4(0.0);
+
+    for (; i < 64.0; i++) {
+
+        q = p = float3(u * d, d + t * 5.0);
+        // mat2(cos(.1*p.z+.1*t+vec4(0,33,11,0))) — column-major: (m00,m10,m01,m11)
+        float4 cs = cos(0.1 * p.z + 0.1 * t + float4(0, 33, 11, 0));
+        float2x2 m = float2x2(cs.x, cs.y, cs.z, cs.w);
+        p.xy = p.xy * m;
+
+        q.xz = cos(q.xz);
+        p.z = cos(p.z);
+
+        for (s = 1.0; s++ < 6.0;) {
+            q += sin(0.6 * t + p.zxy * 0.6);
+            p += sin(t + t + p.yzx * s) * 0.6;
+        }
+
+        s = 0.02 + abs(min(length(p + 3.0 * sin(p.z * 0.5)) - 4.0, length(q - 2.0 * sin(p.z * 0.4)) - 6.0)) * 0.2;
+        d += s;
+
+        float4 brightTerm = min(0.01 * float4(6, 2, 1, 0) / max(length(u * sin(t + t + t)), 0.001), float4(50.0));
+        o += brightTerm + 1.0 / s * length(u);
+    }
+
+    o = tanh(max(o / 6e2 + dot(u, u) * 0.35, 0.0));
+    return o;
+}

shaders/remember/remember.vk.glsl

@@ -0,0 +1,61 @@
+#version 450
+
+// Name: Remember
+// Author: diatribes
+// URL: https://www.shadertoy.com/view/tXSBDK
+
+layout(location = 0) in  vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+
+layout(set = 3, binding = 0) uniform ShadertoyUBO {
+    float iTime;
+    vec2  iResolution;
+};
+
+// fuzzy brain — Hash function to replace iChannel0 texture noise
+float hash12(vec2 p) {
+    vec3 p3 = fract(vec3(p.xyx) * .1031);
+    p3 += dot(p3, p3.yzx + 33.33);
+    return fract((p3.x + p3.y) * p3.z);
+}
+
+void mainImage(out vec4 o, vec2 u) {
+
+    vec3 q, p = vec3(iResolution.xy, iResolution.x / iResolution.y);
+
+    float i = 0.0, s,
+          d = .125 * hash12(u),
+          t = iTime * .1;
+
+    u = (u + u - p.xy) / p.y;
+    if (abs(u.y) > .8) { o = vec4(0); return; }
+
+    o = vec4(0.0);
+
+    for (; i < 64.; i++) {
+
+        q = p = vec3(u * d, d + t * 5.);
+        p.xy *= mat2(cos(.1 * p.z + .1 * t + vec4(0, 33, 11, 0)));
+
+        q.xz = cos(q.xz);
+        p.z = cos(p.z);
+        for (s = 1.; s++ < 6.;
+            q += sin(.6 * t + p.zxy * .6),
+            p += sin(t + t + p.yzx * s) * .6);
+
+        d += s = .02 + abs(min(length(p + 3. * sin(p.z * .5)) - 4., length(q - 2. * sin(p.z * .4)) - 6.)) * .2;
+
+        vec4 brightTerm = min(.01 * vec4(6, 2, 1, 0) / max(length(u * sin(t + t + t)), 0.001), vec4(50.0));
+        o += brightTerm + 1. / s * length(u);
+
+    }
+
+    o = tanh(max(o / 6e2 + dot(u, u) * .35, 0.));
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}

shaders/seascape/meta.txt

@@ -0,0 +1,2 @@
+Name: Seascape
+Author: Alexander Alekseev

shaders/seascape/seascape.frag.msl

@@ -0,0 +1,181 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// Seascape — Alexander Alekseev (TDM, 2014)
+// MSL port of seascape.vk.glsl. iTime threaded through helpers because
+// MSL does not allow file-scope mutable globals.
+
+struct ShadertoyUBO {
+    float iTime;
+    float2 iResolution;
+};
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+constant int NUM_STEPS = 32;
+constant float PI = 3.141592;
+constant float EPSILON = 1e-3;
+
+constant int ITER_GEOMETRY = 3;
+constant int ITER_FRAGMENT = 5;
+constant float SEA_HEIGHT = 0.6;
+constant float SEA_CHOPPY = 4.0;
+constant float SEA_SPEED = 0.8;
+constant float SEA_FREQ = 0.16;
+constant float3 SEA_BASE = float3(0.0, 0.09, 0.18);
+constant float3 SEA_WATER_COLOR = float3(0.8, 0.9, 0.6) * 0.6;
+constant float2x2 octave_m = float2x2(1.6, 1.2, -1.2, 1.6);
+
+static float3x3 fromEuler(float3 ang) {
+    float2 a1 = float2(sin(ang.x), cos(ang.x));
+    float2 a2 = float2(sin(ang.y), cos(ang.y));
+    float2 a3 = float2(sin(ang.z), cos(ang.z));
+    float3x3 m;
+    m[0] = float3(a1.y * a3.y + a1.x * a2.x * a3.x, a1.y * a2.x * a3.x + a3.y * a1.x, -a2.y * a3.x);
+    m[1] = float3(-a2.y * a1.x, a1.y * a2.y, a2.x);
+    m[2] = float3(a3.y * a1.x * a2.x + a1.y * a3.x, a1.x * a3.x - a1.y * a3.y * a2.x, a2.y * a3.y);
+    return m;
+}
+
+static float hash(float2 p) {
+    float h = dot(p, float2(127.1, 311.7));
+    return fract(sin(h) * 43758.5453123);
+}
+
+static float noise(float2 p) {
+    float2 i = floor(p);
+    float2 f = fract(p);
+    float2 u = f * f * (3.0 - 2.0 * f);
+    return -1.0 + 2.0 * mix(mix(hash(i + float2(0.0, 0.0)),
+                                hash(i + float2(1.0, 0.0)), u.x),
+                            mix(hash(i + float2(0.0, 1.0)),
+                                hash(i + float2(1.0, 1.0)), u.x), u.y);
+}
+
+static float diffuseLight(float3 n, float3 l, float p) {
+    return pow(dot(n, l) * 0.4 + 0.6, p);
+}
+
+static float specularLight(float3 n, float3 l, float3 e, float s) {
+    float nrm = (s + 8.0) / (PI * 8.0);
+    return pow(max(dot(reflect(e, n), l), 0.0), s) * nrm;
+}
+
+static float3 getSkyColor(float3 e) {
+    e.y = (max(e.y, 0.0) * 0.8 + 0.2) * 0.8;
+    return float3(pow(1.0 - e.y, 2.0), 1.0 - e.y, 0.6 + (1.0 - e.y) * 0.4) * 1.1;
+}
+
+static float sea_octave(float2 uv, float choppy) {
+    uv += noise(uv);
+    float2 wv = 1.0 - abs(sin(uv));
+    float2 swv = abs(cos(uv));
+    wv = mix(wv, swv, wv);
+    return pow(1.0 - pow(wv.x * wv.y, 0.65), choppy);
+}
+
+static float seaMap(float3 p, float iTime, int iter) {
+    float SEA_TIME = 1.0 + iTime * SEA_SPEED;
+    float freq = SEA_FREQ;
+    float amp = SEA_HEIGHT;
+    float choppy = SEA_CHOPPY;
+    float2 uv = p.xz; uv.x *= 0.75;
+
+    float d, h = 0.0;
+    for (int i = 0; i < iter; i++) {
+        d = sea_octave((uv + SEA_TIME) * freq, choppy);
+        d += sea_octave((uv - SEA_TIME) * freq, choppy);
+        h += d * amp;
+        uv = uv * octave_m;
+        freq *= 1.9;
+        amp *= 0.22;
+        choppy = mix(choppy, 1.0, 0.2);
+    }
+    return p.y - h;
+}
+
+static float3 getSeaColor(float3 p, float3 n, float3 l, float3 eye, float3 dist) {
+    float fresnel = clamp(1.0 - dot(n, -eye), 0.0, 1.0);
+    fresnel = min(fresnel * fresnel * fresnel, 0.5);
+
+    float3 reflected = getSkyColor(reflect(eye, n));
+    float3 refracted = SEA_BASE + diffuseLight(n, l, 80.0) * SEA_WATER_COLOR * 0.12;
+
+    float3 color = mix(refracted, reflected, fresnel);
+
+    float atten = max(1.0 - dot(dist, dist) * 0.001, 0.0);
+    color += SEA_WATER_COLOR * (p.y - SEA_HEIGHT) * 0.18 * atten;
+
+    color += specularLight(n, l, eye, 600.0 * rsqrt(dot(dist, dist)));
+
+    return color;
+}
+
+static float3 getNormal(float3 p, float eps, float iTime) {
+    float3 n;
+    n.y = seaMap(p, iTime, ITER_FRAGMENT);
+    n.x = seaMap(float3(p.x + eps, p.y, p.z), iTime, ITER_FRAGMENT) - n.y;
+    n.z = seaMap(float3(p.x, p.y, p.z + eps), iTime, ITER_FRAGMENT) - n.y;
+    n.y = eps;
+    return normalize(n);
+}
+
+static float heightMapTracing(float3 ori, float3 dir, thread float3& p, float iTime) {
+    float tm = 0.0;
+    float tx = 1000.0;
+    float hx = seaMap(ori + dir * tx, iTime, ITER_GEOMETRY);
+    if (hx > 0.0) {
+        p = ori + dir * tx;
+        return tx;
+    }
+    float hm = seaMap(ori, iTime, ITER_GEOMETRY);
+    for (int i = 0; i < NUM_STEPS; i++) {
+        float tmid = mix(tm, tx, hm / (hm - hx));
+        p = ori + dir * tmid;
+        float hmid = seaMap(p, iTime, ITER_GEOMETRY);
+        if (hmid < 0.0) {
+            tx = tmid;
+            hx = hmid;
+        } else {
+            tm = tmid;
+            hm = hmid;
+        }
+        if (abs(hmid) < EPSILON) break;
+    }
+    return mix(tm, tx, hm / (hm - hx));
+}
+
+static float3 getPixel(float2 coord, float time, float2 iResolution, float iTime) {
+    float2 uv = coord / iResolution;
+    uv = uv * 2.0 - 1.0;
+    uv.x *= iResolution.x / iResolution.y;
+
+    float3 ang = float3(sin(time * 3.0) * 0.1, sin(time) * 0.2 + 0.3, time);
+    float3 ori = float3(0.0, 3.5, time * 5.0);
+    float3 dir = normalize(float3(uv.xy, -2.0));
+    dir.z += length(uv) * 0.14;
+    dir = normalize(dir) * fromEuler(ang);
+
+    float3 p;
+    heightMapTracing(ori, dir, p, iTime);
+    float3 dist = p - ori;
+    float EPSILON_NRM = 0.1 / iResolution.x;
+    float3 n = getNormal(p, dot(dist, dist) * EPSILON_NRM, iTime);
+    float3 light = normalize(float3(0.0, 1.0, 0.8));
+
+    return mix(
+        getSkyColor(dir),
+        getSeaColor(p, n, light, dir, dist),
+        pow(smoothstep(0.0, -0.02, dir.y), 0.2));
+}
+
+fragment float4 seascape_fs(PassthroughVOut in [[stage_in]],
+                            constant ShadertoyUBO& U [[buffer(0)]]) {
+    float2 fragCoord = in.uv * U.iResolution;
+    float time = U.iTime * 0.3;
+    float3 color = getPixel(fragCoord, time, U.iResolution, U.iTime);
+    return float4(pow(color, float3(0.65)), 1.0);
+}

shaders/seascape/seascape.vk.glsl

@@ -0,0 +1,200 @@
+#version 450
+
+// Name: Seascape
+// Author: Alexander Alekseev
+// URL: https://www.shadertoy.com/view/Ms2SD1
+//
+// "Seascape" by Alexander Alekseev aka TDM - 2014
+// CC BY-NC-SA 3.0 Unported License.
+
+layout(location = 0) in  vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+
+layout(set = 3, binding = 0) uniform ShadertoyUBO {
+    float iTime;
+    vec2  iResolution;
+};
+
+const int NUM_STEPS = 32;
+const float PI = 3.141592;
+const float EPSILON = 1e-3;
+#define EPSILON_NRM (0.1 / iResolution.x)
+
+const int ITER_GEOMETRY = 3;
+const int ITER_FRAGMENT = 5;
+const float SEA_HEIGHT = 0.6;
+const float SEA_CHOPPY = 4.0;
+const float SEA_SPEED = 0.8;
+const float SEA_FREQ = 0.16;
+const vec3 SEA_BASE = vec3(0.0, 0.09, 0.18);
+const vec3 SEA_WATER_COLOR = vec3(0.8, 0.9, 0.6) * 0.6;
+#define SEA_TIME (1.0 + iTime * SEA_SPEED)
+const mat2 octave_m = mat2(1.6, 1.2, -1.2, 1.6);
+
+mat3 fromEuler(vec3 ang) {
+    vec2 a1 = vec2(sin(ang.x), cos(ang.x));
+    vec2 a2 = vec2(sin(ang.y), cos(ang.y));
+    vec2 a3 = vec2(sin(ang.z), cos(ang.z));
+    mat3 m;
+    m[0] = vec3(a1.y * a3.y + a1.x * a2.x * a3.x, a1.y * a2.x * a3.x + a3.y * a1.x, -a2.y * a3.x);
+    m[1] = vec3(-a2.y * a1.x, a1.y * a2.y, a2.x);
+    m[2] = vec3(a3.y * a1.x * a2.x + a1.y * a3.x, a1.x * a3.x - a1.y * a3.y * a2.x, a2.y * a3.y);
+    return m;
+}
+
+float hash(vec2 p) {
+    float h = dot(p, vec2(127.1, 311.7));
+    return fract(sin(h) * 43758.5453123);
+}
+
+float noise(in vec2 p) {
+    vec2 i = floor(p);
+    vec2 f = fract(p);
+    vec2 u = f * f * (3.0 - 2.0 * f);
+    return -1.0 + 2.0 * mix(mix(hash(i + vec2(0.0, 0.0)),
+                                hash(i + vec2(1.0, 0.0)), u.x),
+                            mix(hash(i + vec2(0.0, 1.0)),
+                                hash(i + vec2(1.0, 1.0)), u.x), u.y);
+}
+
+float diffuse(vec3 n, vec3 l, float p) {
+    return pow(dot(n, l) * 0.4 + 0.6, p);
+}
+
+float specular(vec3 n, vec3 l, vec3 e, float s) {
+    float nrm = (s + 8.0) / (PI * 8.0);
+    return pow(max(dot(reflect(e, n), l), 0.0), s) * nrm;
+}
+
+vec3 getSkyColor(vec3 e) {
+    e.y = (max(e.y, 0.0) * 0.8 + 0.2) * 0.8;
+    return vec3(pow(1.0 - e.y, 2.0), 1.0 - e.y, 0.6 + (1.0 - e.y) * 0.4) * 1.1;
+}
+
+float sea_octave(vec2 uv, float choppy) {
+    uv += noise(uv);
+    vec2 wv = 1.0 - abs(sin(uv));
+    vec2 swv = abs(cos(uv));
+    wv = mix(wv, swv, wv);
+    return pow(1.0 - pow(wv.x * wv.y, 0.65), choppy);
+}
+
+float map(vec3 p) {
+    float freq = SEA_FREQ;
+    float amp = SEA_HEIGHT;
+    float choppy = SEA_CHOPPY;
+    vec2 uv = p.xz; uv.x *= 0.75;
+
+    float d, h = 0.0;
+    for (int i = 0; i < ITER_GEOMETRY; i++) {
+        d = sea_octave((uv + SEA_TIME) * freq, choppy);
+        d += sea_octave((uv - SEA_TIME) * freq, choppy);
+        h += d * amp;
+        uv *= octave_m; freq *= 1.9; amp *= 0.22;
+        choppy = mix(choppy, 1.0, 0.2);
+    }
+    return p.y - h;
+}
+
+float map_detailed(vec3 p) {
+    float freq = SEA_FREQ;
+    float amp = SEA_HEIGHT;
+    float choppy = SEA_CHOPPY;
+    vec2 uv = p.xz; uv.x *= 0.75;
+
+    float d, h = 0.0;
+    for (int i = 0; i < ITER_FRAGMENT; i++) {
+        d = sea_octave((uv + SEA_TIME) * freq, choppy);
+        d += sea_octave((uv - SEA_TIME) * freq, choppy);
+        h += d * amp;
+        uv *= octave_m; freq *= 1.9; amp *= 0.22;
+        choppy = mix(choppy, 1.0, 0.2);
+    }
+    return p.y - h;
+}
+
+vec3 getSeaColor(vec3 p, vec3 n, vec3 l, vec3 eye, vec3 dist) {
+    float fresnel = clamp(1.0 - dot(n, -eye), 0.0, 1.0);
+    fresnel = min(fresnel * fresnel * fresnel, 0.5);
+
+    vec3 reflected = getSkyColor(reflect(eye, n));
+    vec3 refracted = SEA_BASE + diffuse(n, l, 80.0) * SEA_WATER_COLOR * 0.12;
+
+    vec3 color = mix(refracted, reflected, fresnel);
+
+    float atten = max(1.0 - dot(dist, dist) * 0.001, 0.0);
+    color += SEA_WATER_COLOR * (p.y - SEA_HEIGHT) * 0.18 * atten;
+
+    color += specular(n, l, eye, 600.0 * inversesqrt(dot(dist, dist)));
+
+    return color;
+}
+
+vec3 getNormal(vec3 p, float eps) {
+    vec3 n;
+    n.y = map_detailed(p);
+    n.x = map_detailed(vec3(p.x + eps, p.y, p.z)) - n.y;
+    n.z = map_detailed(vec3(p.x, p.y, p.z + eps)) - n.y;
+    n.y = eps;
+    return normalize(n);
+}
+
+float heightMapTracing(vec3 ori, vec3 dir, out vec3 p) {
+    float tm = 0.0;
+    float tx = 1000.0;
+    float hx = map(ori + dir * tx);
+    if (hx > 0.0) {
+        p = ori + dir * tx;
+        return tx;
+    }
+    float hm = map(ori);
+    for (int i = 0; i < NUM_STEPS; i++) {
+        float tmid = mix(tm, tx, hm / (hm - hx));
+        p = ori + dir * tmid;
+        float hmid = map(p);
+        if (hmid < 0.0) {
+            tx = tmid;
+            hx = hmid;
+        } else {
+            tm = tmid;
+            hm = hmid;
+        }
+        if (abs(hmid) < EPSILON) break;
+    }
+    return mix(tm, tx, hm / (hm - hx));
+}
+
+vec3 getPixel(in vec2 coord, float time) {
+    vec2 uv = coord / iResolution.xy;
+    uv = uv * 2.0 - 1.0;
+    uv.x *= iResolution.x / iResolution.y;
+
+    vec3 ang = vec3(sin(time * 3.0) * 0.1, sin(time) * 0.2 + 0.3, time);
+    vec3 ori = vec3(0.0, 3.5, time * 5.0);
+    vec3 dir = normalize(vec3(uv.xy, -2.0)); dir.z += length(uv) * 0.14;
+    dir = normalize(dir) * fromEuler(ang);
+
+    vec3 p;
+    heightMapTracing(ori, dir, p);
+    vec3 dist = p - ori;
+    vec3 n = getNormal(p, dot(dist, dist) * EPSILON_NRM);
+    vec3 light = normalize(vec3(0.0, 1.0, 0.8));
+
+    return mix(
+        getSkyColor(dir),
+        getSeaColor(p, n, light, dir, dist),
+        pow(smoothstep(0.0, -0.02, dir.y), 0.2));
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord) {
+    float time = iTime * 0.3;
+    vec3 color = getPixel(fragCoord, time);
+    fragColor = vec4(pow(color, vec3(0.65)), 1.0);
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}

shaders/shader_art_coding_introduction/meta.txt

@@ -0,0 +1,2 @@
+Name: Shader Art Coding Introduction
+Author: kishimisu

shaders/shader_art_coding_introduction/shader_art_coding_introduction.frag.msl

@@ -0,0 +1,47 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// Shader Art Coding Introduction — kishimisu
+// MSL port of shader_art_coding_introduction.vk.glsl.
+
+struct ShadertoyUBO {
+    float iTime;
+    float2 iResolution;
+};
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+static float3 palette(float t) {
+    float3 a = float3(0.5, 0.5, 0.5);
+    float3 b = float3(0.5, 0.5, 0.5);
+    float3 c = float3(1.0, 1.0, 1.0);
+    float3 d = float3(0.263, 0.416, 0.557);
+    return a + b * cos(6.28318 * (c * t * d));
+}
+
+fragment float4 shader_art_coding_introduction_fs(PassthroughVOut in [[stage_in]],
+                                                   constant ShadertoyUBO& U [[buffer(0)]]) {
+    float2 fragCoord = in.uv * U.iResolution;
+    float2 uv = (fragCoord * 2.0 - U.iResolution) / U.iResolution.y;
+    float2 uv0 = uv;
+    float3 finalColor = float3(0.0);
+
+    for (float i = 0.0; i < 4.0; i++) {
+        uv = fract(uv * 1.5) - 0.5;
+
+        float d = length(uv) * exp(-length(uv0));
+
+        float3 col = palette(length(uv0) + i * 0.4 + U.iTime * 0.4);
+
+        d = sin(d * 8.0 + U.iTime) / 8.0;
+        d = abs(d);
+        d = pow(0.01 / d, 1.2);
+
+        finalColor += col * d;
+    }
+
+    return float4(finalColor, 1.0);
+}

shaders/shader_art_coding_introduction/shader_art_coding_introduction.vk.glsl

@@ -0,0 +1,50 @@
+#version 450
+
+// Name: Shader Art Coding Introduction
+// Author: kishimisu
+// URL: https://www.shadertoy.com/view/mtyGWy
+
+layout(location = 0) in  vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+
+layout(set = 3, binding = 0) uniform ShadertoyUBO {
+    float iTime;
+    vec2  iResolution;
+};
+
+vec3 palette(float t) {
+    vec3 a = vec3(0.5, 0.5, 0.5);
+    vec3 b = vec3(0.5, 0.5, 0.5);
+    vec3 c = vec3(1.0, 1.0, 1.0);
+    vec3 d = vec3(0.263, 0.416, 0.557);
+    return a + b * cos(6.28318 * (c * t * d));
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord) {
+    vec2 uv = (fragCoord * 2.0 - iResolution.xy) / iResolution.y;
+    vec2 uv0 = uv;
+    vec3 finalColor = vec3(0.0);
+
+    for (float i = 0.0; i < 4.0; i++) {
+        uv = fract(uv * 1.5) - 0.5;
+
+        float d = length(uv) * exp(-length(uv0));
+
+        vec3 col = palette(length(uv0) + i * 0.4 + iTime * 0.4);
+
+        d = sin(d * 8.0 + iTime) / 8.0;
+        d = abs(d);
+        d = pow(0.01 / d, 1.2);
+
+        finalColor += col * d;
+    }
+
+    fragColor = vec4(finalColor, 1.0);
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}

shaders/test/meta.txt

@@ -0,0 +1,2 @@
+Name: Test
+Author: JailDesigner

shaders/test/test.frag.msl

@@ -0,0 +1,36 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// Test shader (Metal Shading Language port of test.vk.glsl).
+// Author: JailDesigner
+
+struct ShadertoyUBO {
+    float iTime;
+    float2 iResolution;
+};
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+static float3 palette(float t) {
+    float3 a = float3(1.0, 0.5, 0.5);
+    float3 b = float3(1.0, 0.5, 0.5);
+    float3 c = float3(1.0, 1.0, 1.0);
+    float3 d = float3(0.263, 0.416, 0.557);
+    return a + b * cos(6.28318 * (c * t * d));
+}
+
+fragment float4 test_fs(PassthroughVOut in [[stage_in]],
+                        constant ShadertoyUBO& u [[buffer(0)]]) {
+    float2 fragCoord = in.uv * u.iResolution;
+    float2 uv = (fragCoord * 2.0 - u.iResolution) / u.iResolution.y;
+    float d = length(uv);
+    float3 col = palette(d);
+    d = sin(d * 8.0 + u.iTime) / 8.0;
+    d = abs(d);
+    d = 0.02 / d;
+    col *= d;
+    return float4(col, 1.0);
+}

shaders/test/test.vk.glsl

@@ -0,0 +1,42 @@
+#version 450
+
+// Name: Test
+// Author: JailDesigner
+//
+// Vulkan port of test.gl.glsl. Bindings follow the SDL3 GPU convention:
+//   set=3, binding=0 — fragment uniform buffer (anonymous block: members
+//   are accessible directly as iTime / iResolution, like Shadertoy).
+
+layout(location = 0) in  vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+
+layout(set = 3, binding = 0) uniform ShadertoyUBO {
+    float iTime;
+    vec2  iResolution;
+};
+
+vec3 palette(float t) {
+    vec3 a = vec3(1.0, 0.5, 0.5);
+    vec3 b = vec3(1.0, 0.5, 0.5);
+    vec3 c = vec3(1.0, 1.0, 1.0);
+    vec3 d = vec3(0.263, 0.416, 0.557);
+    return a + b * cos(6.28318 * (c * t * d));
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord) {
+    vec2 uv = (fragCoord * 2.0 - iResolution) / iResolution.y;
+    float d = length(uv);
+    vec3 col = palette(d);
+    d = sin(d * 8.0 + iTime) / 8.0;
+    d = abs(d);
+    d = 0.02 / d;
+    col *= d;
+    fragColor = vec4(col, 1.0);
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}

shaders/water/meta.txt

@@ -0,0 +1,2 @@
+Name: Water
+Author: diatribes

shaders/water/water.frag.msl

@@ -0,0 +1,40 @@
+#include <metal_stdlib>
+using namespace metal;
+
+// Water — diatribes
+// MSL port of water.vk.glsl. Entry point is named after the shader (water_fs).
+
+struct ShadertoyUBO {
+    float iTime;
+    float2 iResolution;
+};
+
+struct PassthroughVOut {
+    float4 pos [[position]];
+    float2 uv;
+};
+
+fragment float4 water_fs(PassthroughVOut in [[stage_in]],
+                         constant ShadertoyUBO& U [[buffer(0)]]) {
+    float2 fragCoord = in.uv * U.iResolution;
+    float2 u = fragCoord;
+
+    float s = 0.002, i = 0.0, n;
+    float3 r = float3(U.iResolution, U.iResolution.x / U.iResolution.y);
+    float3 p = float3(0);
+    u = (u - r.xy / 2.0) / r.y - 0.3;
+
+    float4 o = float4(0);
+
+    for (; i < 32.0 && s > 0.001; i++) {
+        float4 term = float4(5, 2, 1, 0) / max(length(u - 0.1), 0.001);
+        o += min(term, float4(100.0));
+        p += float3(u * s, s);
+        s = 1.0 + p.y;
+        for (n = 0.01; n < 1.0; n += n) {
+            s += abs(dot(sin(p.z + U.iTime + p / n), float3(1))) * n * 0.1;
+        }
+    }
+    o = tanh(o / 5e2);
+    return o;
+}

shaders/water/water.vk.glsl

@@ -0,0 +1,45 @@
+#version 450
+
+// Name: Water
+// Author: diatribes
+// URL: https://www.shadertoy.com/view/tXjXDy
+
+layout(location = 0) in  vec2 vUV;
+layout(location = 0) out vec4 FragColor;
+
+layout(set = 3, binding = 0) uniform ShadertoyUBO {
+    float iTime;
+    vec2  iResolution;
+};
+
+/*
+    -2 by @FabriceNeyret2
+    thanks!!  :D
+
+    If it doesn't display correctly, change line "r/r" to "vec3(1)"
+*/
+
+void mainImage( out vec4 o, vec2 u ) {
+    float s=.002, i=0., n;
+    vec3 r = vec3(iResolution.xy, iResolution.x/iResolution.y);
+    vec3 p = vec3(0);
+    u = (u-r.xy/2.)/r.y-.3;
+
+    o = vec4(0);
+
+    for(; i < 32. && s > .001; i++) {
+        vec4 term = vec4(5,2,1,0)/max(length(u-.1), 0.001);
+        o += min(term, vec4(100.0));
+        for (p += vec3(u*s,s), s = 1. + p.y, n =.01; n < 1.; n+=n) {
+            s += abs(dot(sin(p.z+iTime+p / n), vec3(1))) * n*.1;
+        }
+    }
+    o = tanh(o/5e2);
+}
+
+void main() {
+    vec2 fragCoordPixels = vUV * iResolution;
+    vec4 outColor;
+    mainImage(outColor, fragCoordPixels);
+    FragColor = outColor;
+}

src/defines.hpp

@@ -6,6 +6,9 @@
 // Nombre de la aplicación
 constexpr const char* APP_NAME = "Shadertoy";
 
+// Prefijo del título de la ventana (estilo aee_2026).
+constexpr const char* WINDOW_TITLE_PREFIX = "\xC2\xA9 2025 Shadertoy \xE2\x80\x94 JailDesigner";
+
 // Tamaño de ventana por defecto
 constexpr int WINDOW_WIDTH = 800;
 constexpr int WINDOW_HEIGHT = 800;

src/rendering/opengl_shader_backend.cpp

@@ -0,0 +1,297 @@
+#include "rendering/opengl_shader_backend.hpp"
+
+#include <iostream>
+#include <vector>
+
+namespace Rendering {
+
+    namespace {
+
+        constexpr const char* VERTEX_SHADER_SRC = R"glsl(
+#version 330 core
+layout(location = 0) in vec2 aPos;
+out vec2 vUV;
+void main() {
+    vUV = aPos * 0.5 + 0.5;
+    gl_Position = vec4(aPos, 0.0, 1.0);
+}
+)glsl";
+
+        void logInfo(const std::string& msg) { std::cout << "[INFO] " << msg << '\n'; }
+        void logError(const std::string& msg) { std::cerr << "[ERROR] " << msg << '\n'; }
+
+        auto compileShader(GLenum type, const char* src) -> GLuint {
+            const GLuint s = glCreateShader(type);
+            glShaderSource(s, 1, &src, nullptr);
+            glCompileShader(s);
+            GLint ok = 0;
+            glGetShaderiv(s, GL_COMPILE_STATUS, &ok);
+            if (ok == 0) {
+                GLint len = 0;
+                glGetShaderiv(s, GL_INFO_LOG_LENGTH, &len);
+                std::string log(len > 0 ? len : 1, ' ');
+                glGetShaderInfoLog(s, len, nullptr, log.data());
+                logError("Shader compile error: " + log);
+                glDeleteShader(s);
+                return 0;
+            }
+            return s;
+        }
+
+        auto linkProgram(GLuint vs, GLuint fs) -> GLuint {
+            const GLuint p = glCreateProgram();
+            glAttachShader(p, vs);
+            glAttachShader(p, fs);
+            glLinkProgram(p);
+            GLint ok = 0;
+            glGetProgramiv(p, GL_LINK_STATUS, &ok);
+            if (ok == 0) {
+                GLint len = 0;
+                glGetProgramiv(p, GL_INFO_LOG_LENGTH, &len);
+                std::string log(len > 0 ? len : 1, ' ');
+                glGetProgramInfoLog(p, len, nullptr, log.data());
+                logError("Program link error: " + log);
+                glDeleteProgram(p);
+                return 0;
+            }
+            return p;
+        }
+
+        auto detectFeedbackChannel(const ShaderMetadata& metadata) -> int {
+            if (metadata.iChannel0 == "self") { return 0; }
+            if (metadata.iChannel1 == "self") { return 1; }
+            if (metadata.iChannel2 == "self") { return 2; }
+            if (metadata.iChannel3 == "self") { return 3; }
+            return -1;
+        }
+
+    }  // namespace
+
+    OpenGLShaderBackend::~OpenGLShaderBackend() { cleanup(); }
+
+    auto OpenGLShaderBackend::init(SDL_Window* window) -> bool {
+        window_ = window;
+
+        gl_context_ = SDL_GL_CreateContext(window_);
+        if (gl_context_ == nullptr) {
+            logError(std::string("SDL_GL_CreateContext error: ") + SDL_GetError());
+            return false;
+        }
+
+        if (gladLoadGLLoader(reinterpret_cast<GLADloadproc>(SDL_GL_GetProcAddress)) == 0) {
+            logError("Failed to initialize GL loader");
+            SDL_GL_DestroyContext(gl_context_);
+            gl_context_ = nullptr;
+            return false;
+        }
+
+        constexpr float QUAD_VERTICES[] = {
+            -1.0f, -1.0f,
+             1.0f, -1.0f,
+            -1.0f,  1.0f,
+             1.0f,  1.0f,
+        };
+
+        glGenVertexArrays(1, &vao_);
+        glGenBuffers(1, &vbo_);
+        glBindVertexArray(vao_);
+        glBindBuffer(GL_ARRAY_BUFFER, vbo_);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(QUAD_VERTICES), QUAD_VERTICES, GL_STATIC_DRAW);
+        glEnableVertexAttribArray(0);
+        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), nullptr);
+        glBindBuffer(GL_ARRAY_BUFFER, 0);
+        glBindVertexArray(0);
+
+        return true;
+    }
+
+    auto OpenGLShaderBackend::loadShader(const ShaderProgramSpec& spec) -> bool {
+        const std::filesystem::path source_path = spec.folder / (spec.base_name + ".gl.glsl");
+
+        std::string fragSrc;
+        if (!loadFileToString(source_path, fragSrc)) {
+            logError("Failed to load shader file: " + source_path.string());
+            return false;
+        }
+
+        const int feedback = detectFeedbackChannel(spec.metadata);
+
+        const GLuint vs = compileShader(GL_VERTEX_SHADER, VERTEX_SHADER_SRC);
+        const GLuint fs = compileShader(GL_FRAGMENT_SHADER, fragSrc.c_str());
+
+        if (vs == 0 || fs == 0) {
+            if (vs != 0) { glDeleteShader(vs); }
+            if (fs != 0) { glDeleteShader(fs); }
+            logError("Shader compilation failed for: " + source_path.string());
+            return false;
+        }
+
+        const GLuint program = linkProgram(vs, fs);
+        glDeleteShader(vs);
+        glDeleteShader(fs);
+
+        if (program == 0) {
+            logError("Program linking failed for: " + source_path.string());
+            return false;
+        }
+
+        if (current_program_ != 0) {
+            glDeleteProgram(current_program_);
+        }
+        current_program_ = program;
+
+        destroyFeedbackFBO();
+        feedback_channel_ = feedback;
+        current_shader_uses_feedback_ = (feedback >= 0);
+
+        if (current_shader_uses_feedback_) {
+            logInfo("Shader uses self-feedback on iChannel" + std::to_string(feedback_channel_));
+        }
+
+        logInfo("Shader loaded successfully: " + spec.base_name);
+        return true;
+    }
+
+    auto OpenGLShaderBackend::createFeedbackFBO(int width, int height) -> bool {
+        destroyFeedbackFBO();
+
+        glGenTextures(1, &feedback_texture_);
+        glBindTexture(GL_TEXTURE_2D, feedback_texture_);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+
+        std::vector<float> black(static_cast<std::size_t>(width) * static_cast<std::size_t>(height) * 4U, 0.0f);
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, width, height, 0, GL_RGBA, GL_FLOAT, black.data());
+        glBindTexture(GL_TEXTURE_2D, 0);
+
+        glGenFramebuffers(1, &feedback_fbo_);
+        glBindFramebuffer(GL_FRAMEBUFFER, feedback_fbo_);
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, feedback_texture_, 0);
+
+        const GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
+        glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+        if (status != GL_FRAMEBUFFER_COMPLETE) {
+            logError("Feedback FBO creation failed: " + std::to_string(status));
+            destroyFeedbackFBO();
+            return false;
+        }
+
+        feedback_width_ = width;
+        feedback_height_ = height;
+        logInfo("Created feedback FBO (" + std::to_string(width) + "x" + std::to_string(height) + ")");
+        return true;
+    }
+
+    void OpenGLShaderBackend::destroyFeedbackFBO() {
+        if (feedback_fbo_ != 0) {
+            glDeleteFramebuffers(1, &feedback_fbo_);
+            feedback_fbo_ = 0;
+        }
+        if (feedback_texture_ != 0) {
+            glDeleteTextures(1, &feedback_texture_);
+            feedback_texture_ = 0;
+        }
+        feedback_width_ = 0;
+        feedback_height_ = 0;
+    }
+
+    void OpenGLShaderBackend::render(const ShaderUniforms& uniforms) {
+        if (current_program_ == 0 || window_ == nullptr) { return; }
+
+        int w = 0;
+        int h = 0;
+        SDL_GetWindowSize(window_, &w, &h);
+
+        if (current_shader_uses_feedback_) {
+            if (feedback_fbo_ == 0 || feedback_width_ != w || feedback_height_ != h) {
+                createFeedbackFBO(w, h);
+            }
+        }
+
+        glUseProgram(current_program_);
+
+        const GLint locRes = glGetUniformLocation(current_program_, "iResolution");
+        const GLint locTime = glGetUniformLocation(current_program_, "iTime");
+
+        if (current_shader_uses_feedback_) {
+            const std::string channel_name = "iChannel" + std::to_string(feedback_channel_);
+            const GLint locChannel = glGetUniformLocation(current_program_, channel_name.c_str());
+
+            if (locChannel >= 0) {
+                glActiveTexture(GL_TEXTURE0 + feedback_channel_);
+                glBindTexture(GL_TEXTURE_2D, feedback_texture_);
+                glUniform1i(locChannel, feedback_channel_);
+            }
+
+            glBindFramebuffer(GL_FRAMEBUFFER, feedback_fbo_);
+            glViewport(0, 0, w, h);
+            glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+            glClear(GL_COLOR_BUFFER_BIT);
+
+            if (locRes >= 0) { glUniform2f(locRes, static_cast<float>(w), static_cast<float>(h)); }
+            if (locTime >= 0) { glUniform1f(locTime, uniforms.iTime); }
+
+            glBindVertexArray(vao_);
+            glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+            glBindVertexArray(0);
+
+            glBindFramebuffer(GL_FRAMEBUFFER, 0);
+            glViewport(0, 0, w, h);
+
+            if (locRes >= 0) { glUniform2f(locRes, static_cast<float>(w), static_cast<float>(h)); }
+            if (locTime >= 0) { glUniform1f(locTime, uniforms.iTime); }
+
+            glBindVertexArray(vao_);
+            glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+            glBindVertexArray(0);
+
+            glActiveTexture(GL_TEXTURE0 + feedback_channel_);
+            glBindTexture(GL_TEXTURE_2D, 0);
+        } else {
+            glViewport(0, 0, w, h);
+            glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+            glClear(GL_COLOR_BUFFER_BIT);
+
+            if (locRes >= 0) { glUniform2f(locRes, static_cast<float>(w), static_cast<float>(h)); }
+            if (locTime >= 0) { glUniform1f(locTime, uniforms.iTime); }
+
+            glBindVertexArray(vao_);
+            glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+            glBindVertexArray(0);
+        }
+
+        SDL_GL_SwapWindow(window_);
+    }
+
+    void OpenGLShaderBackend::setVSync(bool vsync) {
+        const int result = SDL_GL_SetSwapInterval(vsync ? 1 : 0);
+        if (result == 0) {
+            logInfo(vsync ? "VSync enabled" : "VSync disabled");
+        } else {
+            logError(std::string("Failed to set VSync: ") + SDL_GetError());
+        }
+    }
+
+    void OpenGLShaderBackend::cleanup() {
+        if (gl_context_ == nullptr) { return; }
+
+        if (vbo_ != 0) { glDeleteBuffers(1, &vbo_); vbo_ = 0; }
+        if (vao_ != 0) { glDeleteVertexArrays(1, &vao_); vao_ = 0; }
+        if (current_program_ != 0) { glDeleteProgram(current_program_); current_program_ = 0; }
+        destroyFeedbackFBO();
+        current_shader_uses_feedback_ = false;
+        feedback_channel_ = -1;
+
+        SDL_GL_DestroyContext(gl_context_);
+        gl_context_ = nullptr;
+        window_ = nullptr;
+    }
+
+    auto makeOpenGLBackend() -> std::unique_ptr<IShaderBackend> {
+        return std::make_unique<OpenGLShaderBackend>();
+    }
+
+}  // namespace Rendering

src/rendering/opengl_shader_backend.hpp

@@ -0,0 +1,40 @@
+#pragma once
+
+#include <glad/glad.h>
+
+#include "rendering/shader_backend.hpp"
+
+namespace Rendering {
+
+    class OpenGLShaderBackend final : public IShaderBackend {
+       public:
+        OpenGLShaderBackend() = default;
+        ~OpenGLShaderBackend() override;
+
+        auto init(SDL_Window* window) -> bool override;
+        auto loadShader(const ShaderProgramSpec& spec) -> bool override;
+        void render(const ShaderUniforms& uniforms) override;
+        void setVSync(bool vsync) override;
+        void cleanup() override;
+        [[nodiscard]] auto driverName() const -> std::string override { return "OpenGL"; }
+
+       private:
+        auto createFeedbackFBO(int width, int height) -> bool;
+        void destroyFeedbackFBO();
+
+        SDL_Window* window_{nullptr};
+        SDL_GLContext gl_context_{nullptr};
+
+        GLuint vao_{0};
+        GLuint vbo_{0};
+        GLuint current_program_{0};
+
+        GLuint feedback_fbo_{0};
+        GLuint feedback_texture_{0};
+        bool current_shader_uses_feedback_{false};
+        int feedback_channel_{-1};
+        int feedback_width_{0};
+        int feedback_height_{0};
+    };
+
+}  // namespace Rendering

src/rendering/sdl3gpu/sdl3gpu_shader_backend.cpp

@@ -0,0 +1,238 @@
+#include "rendering/sdl3gpu/sdl3gpu_shader_backend.hpp"
+
+#include <iostream>
+
+#include "rendering/sdl3gpu/shader_factory.hpp"
+
+namespace Rendering {
+
+    namespace {
+
+        void logInfo(const std::string& msg) { std::cout << "[INFO] " << msg << '\n'; }
+        void logError(const std::string& msg) { std::cerr << "[ERROR] " << msg << '\n'; }
+
+#ifdef __APPLE__
+        constexpr SDL_GPUShaderFormat SHADER_FORMAT = SDL_GPU_SHADERFORMAT_MSL;
+        constexpr const char* VERTEX_ENTRY = "passthrough_vs";
+        constexpr const char* FRAGMENT_ENTRY = "test_fs";  // overridden per-shader (see loadShader)
+        constexpr const char* VERTEX_SUFFIX = ".vert.msl";
+        constexpr const char* FRAGMENT_SUFFIX = ".frag.msl";
+#else
+        constexpr SDL_GPUShaderFormat SHADER_FORMAT = SDL_GPU_SHADERFORMAT_SPIRV;
+        constexpr const char* VERTEX_ENTRY = "main";
+        constexpr const char* FRAGMENT_ENTRY = "main";
+        constexpr const char* VERTEX_SUFFIX = ".vert.spv";
+        constexpr const char* FRAGMENT_SUFFIX = ".frag.spv";
+#endif
+
+    }  // namespace
+
+    Sdl3GpuShaderBackend::~Sdl3GpuShaderBackend() { cleanup(); }
+
+    auto Sdl3GpuShaderBackend::init(SDL_Window* window) -> bool {
+        window_ = window;
+        return createDevice();
+    }
+
+    auto Sdl3GpuShaderBackend::createDevice() -> bool {
+        device_ = SDL_CreateGPUDevice(SHADER_FORMAT, false, nullptr);
+        if (device_ == nullptr) {
+            logError(std::string("SDL_CreateGPUDevice failed: ") + SDL_GetError());
+            return false;
+        }
+        if (!SDL_ClaimWindowForGPUDevice(device_, window_)) {
+            logError(std::string("SDL_ClaimWindowForGPUDevice failed: ") + SDL_GetError());
+            SDL_DestroyGPUDevice(device_);
+            device_ = nullptr;
+            return false;
+        }
+        SDL_SetGPUSwapchainParameters(device_, window_, SDL_GPU_SWAPCHAINCOMPOSITION_SDR, bestPresentMode());
+
+        const char* name = SDL_GetGPUDeviceDriver(device_);
+        const std::string raw = (name != nullptr) ? name : "GPU";
+        if (raw == "vulkan") { driver_name_ = "Vulkan"; }
+        else if (raw == "metal") { driver_name_ = "Metal"; }
+        else if (raw == "d3d12") { driver_name_ = "D3D12"; }
+        else if (!raw.empty()) {
+            driver_name_ = raw;
+            driver_name_[0] = static_cast<char>(std::toupper(static_cast<unsigned char>(driver_name_[0])));
+        } else {
+            driver_name_ = "GPU";
+        }
+        logInfo("GPU driver: " + driver_name_);
+        return true;
+    }
+
+    auto Sdl3GpuShaderBackend::loadVertexShaderFor(const ShaderProgramSpec& spec) -> bool {
+        if (vertex_shader_ != nullptr) { return true; }
+
+        const std::filesystem::path common_dir = spec.folder.parent_path() / "_common";
+        const std::filesystem::path vertex_path = common_dir / (std::string("passthrough") + VERTEX_SUFFIX);
+
+        vertex_shader_ = Sdl3Gpu::loadShaderFromFile(device_, vertex_path, SHADER_FORMAT,
+            VERTEX_ENTRY, SDL_GPU_SHADERSTAGE_VERTEX, 0, 0);
+        if (vertex_shader_ == nullptr) {
+            logError("Failed to load shared vertex shader: " + vertex_path.string() + " (" + SDL_GetError() + ")");
+            return false;
+        }
+        logInfo("Loaded shared vertex shader: " + vertex_path.filename().string());
+        return true;
+    }
+
+    auto Sdl3GpuShaderBackend::buildPipeline(SDL_GPUShader* fragment) -> SDL_GPUGraphicsPipeline* {
+        const SDL_GPUTextureFormat SWAPCHAIN_FORMAT = SDL_GetGPUSwapchainTextureFormat(device_, window_);
+
+        SDL_GPUColorTargetBlendState no_blend{};
+        SDL_GPUColorTargetDescription color_target{};
+        color_target.format = SWAPCHAIN_FORMAT;
+        color_target.blend_state = no_blend;
+
+        SDL_GPUGraphicsPipelineCreateInfo info{};
+        info.vertex_shader = vertex_shader_;
+        info.fragment_shader = fragment;
+        info.primitive_type = SDL_GPU_PRIMITIVETYPE_TRIANGLELIST;
+        info.target_info.num_color_targets = 1;
+        info.target_info.color_target_descriptions = &color_target;
+
+        SDL_GPUGraphicsPipeline* pipeline = SDL_CreateGPUGraphicsPipeline(device_, &info);
+        if (pipeline == nullptr) {
+            logError(std::string("SDL_CreateGPUGraphicsPipeline failed: ") + SDL_GetError());
+        }
+        return pipeline;
+    }
+
+    auto Sdl3GpuShaderBackend::loadShader(const ShaderProgramSpec& spec) -> bool {
+        if (device_ == nullptr) { return false; }
+
+        if (!loadVertexShaderFor(spec)) { return false; }
+
+        const std::filesystem::path frag_path = spec.folder / (spec.base_name + FRAGMENT_SUFFIX);
+
+#ifdef __APPLE__
+        const std::string entry = spec.base_name + "_fs";
+        const char* fragment_entry = entry.c_str();
+#else
+        const char* fragment_entry = FRAGMENT_ENTRY;
+#endif
+
+        SDL_GPUShader* new_fragment = Sdl3Gpu::loadShaderFromFile(device_, frag_path, SHADER_FORMAT,
+            fragment_entry, SDL_GPU_SHADERSTAGE_FRAGMENT, 0, 1);
+        if (new_fragment == nullptr) {
+            logError("Failed to load fragment shader: " + frag_path.string() + " (" + SDL_GetError() + ")");
+            return false;
+        }
+
+        SDL_GPUGraphicsPipeline* new_pipeline = buildPipeline(new_fragment);
+        if (new_pipeline == nullptr) {
+            SDL_ReleaseGPUShader(device_, new_fragment);
+            return false;
+        }
+
+        SDL_WaitForGPUIdle(device_);
+        if (pipeline_ != nullptr) { SDL_ReleaseGPUGraphicsPipeline(device_, pipeline_); }
+        if (fragment_shader_ != nullptr) { SDL_ReleaseGPUShader(device_, fragment_shader_); }
+
+        pipeline_ = new_pipeline;
+        fragment_shader_ = new_fragment;
+        logInfo("Shader loaded successfully: " + spec.base_name);
+        return true;
+    }
+
+    void Sdl3GpuShaderBackend::render(const ShaderUniforms& uniforms) {
+        if (device_ == nullptr || pipeline_ == nullptr) { return; }
+
+        SDL_GPUCommandBuffer* cmd = SDL_AcquireGPUCommandBuffer(device_);
+        if (cmd == nullptr) { return; }
+
+        SDL_GPUTexture* swapchain = nullptr;
+        Uint32 sw = 0;
+        Uint32 sh = 0;
+        if (!SDL_AcquireGPUSwapchainTexture(cmd, window_, &swapchain, &sw, &sh) || swapchain == nullptr) {
+            SDL_SubmitGPUCommandBuffer(cmd);
+            return;
+        }
+
+        SDL_GPUColorTargetInfo color_target{};
+        color_target.texture = swapchain;
+        color_target.load_op = SDL_GPU_LOADOP_CLEAR;
+        color_target.store_op = SDL_GPU_STOREOP_STORE;
+        color_target.clear_color = {.r = 0.0f, .g = 0.0f, .b = 0.0f, .a = 1.0f};
+
+        SDL_GPURenderPass* pass = SDL_BeginGPURenderPass(cmd, &color_target, 1, nullptr);
+        if (pass != nullptr) {
+            SDL_GPUViewport vp{};
+            vp.x = 0.0f;
+            vp.y = 0.0f;
+            vp.w = static_cast<float>(sw);
+            vp.h = static_cast<float>(sh);
+            vp.min_depth = 0.0f;
+            vp.max_depth = 1.0f;
+            SDL_SetGPUViewport(pass, &vp);
+
+            SDL_BindGPUGraphicsPipeline(pass, pipeline_);
+
+            UniformsStd140 ubo{};
+            ubo.iTime = uniforms.iTime;
+            ubo.iResolutionX = uniforms.iResolutionX;
+            ubo.iResolutionY = uniforms.iResolutionY;
+            SDL_PushGPUFragmentUniformData(cmd, 0, &ubo, sizeof(ubo));
+
+            SDL_DrawGPUPrimitives(pass, 3, 1, 0, 0);
+            SDL_EndGPURenderPass(pass);
+        }
+
+        SDL_SubmitGPUCommandBuffer(cmd);
+    }
+
+    void Sdl3GpuShaderBackend::setVSync(bool vsync) {
+        vsync_ = vsync;
+        if (device_ != nullptr && window_ != nullptr) {
+            SDL_SetGPUSwapchainParameters(device_, window_, SDL_GPU_SWAPCHAINCOMPOSITION_SDR, bestPresentMode());
+            logInfo(vsync ? "VSync enabled" : "VSync disabled");
+        }
+    }
+
+    auto Sdl3GpuShaderBackend::bestPresentMode() const -> SDL_GPUPresentMode {
+        if (vsync_) { return SDL_GPU_PRESENTMODE_VSYNC; }
+        if (device_ != nullptr && window_ != nullptr) {
+            if (SDL_WindowSupportsGPUPresentMode(device_, window_, SDL_GPU_PRESENTMODE_IMMEDIATE)) {
+                return SDL_GPU_PRESENTMODE_IMMEDIATE;
+            }
+            if (SDL_WindowSupportsGPUPresentMode(device_, window_, SDL_GPU_PRESENTMODE_MAILBOX)) {
+                return SDL_GPU_PRESENTMODE_MAILBOX;
+            }
+        }
+        return SDL_GPU_PRESENTMODE_VSYNC;
+    }
+
+    void Sdl3GpuShaderBackend::cleanup() {
+        if (device_ == nullptr) { return; }
+
+        SDL_WaitForGPUIdle(device_);
+
+        if (pipeline_ != nullptr) {
+            SDL_ReleaseGPUGraphicsPipeline(device_, pipeline_);
+            pipeline_ = nullptr;
+        }
+        if (fragment_shader_ != nullptr) {
+            SDL_ReleaseGPUShader(device_, fragment_shader_);
+            fragment_shader_ = nullptr;
+        }
+        if (vertex_shader_ != nullptr) {
+            SDL_ReleaseGPUShader(device_, vertex_shader_);
+            vertex_shader_ = nullptr;
+        }
+
+        if (window_ != nullptr) {
+            SDL_ReleaseWindowFromGPUDevice(device_, window_);
+        }
+        SDL_DestroyGPUDevice(device_);
+        device_ = nullptr;
+        window_ = nullptr;
+    }
+
+    auto makeSdl3GpuBackend() -> std::unique_ptr<IShaderBackend> {
+        return std::make_unique<Sdl3GpuShaderBackend>();
+    }
+
+}  // namespace Rendering

src/rendering/sdl3gpu/sdl3gpu_shader_backend.hpp

@@ -0,0 +1,44 @@
+#pragma once
+
+#include <SDL3/SDL.h>
+
+#include "rendering/shader_backend.hpp"
+
+namespace Rendering {
+
+    class Sdl3GpuShaderBackend final : public IShaderBackend {
+       public:
+        Sdl3GpuShaderBackend() = default;
+        ~Sdl3GpuShaderBackend() override;
+
+        auto init(SDL_Window* window) -> bool override;
+        auto loadShader(const ShaderProgramSpec& spec) -> bool override;
+        void render(const ShaderUniforms& uniforms) override;
+        void setVSync(bool vsync) override;
+        void cleanup() override;
+        [[nodiscard]] auto driverName() const -> std::string override { return driver_name_; }
+
+       private:
+        struct UniformsStd140 {
+            float iTime{0.0f};
+            float pad0{0.0f};
+            float iResolutionX{0.0f};
+            float iResolutionY{0.0f};
+        };
+
+        auto createDevice() -> bool;
+        auto loadVertexShaderFor(const ShaderProgramSpec& spec) -> bool;
+        auto buildPipeline(SDL_GPUShader* fragment) -> SDL_GPUGraphicsPipeline*;
+        [[nodiscard]] auto bestPresentMode() const -> SDL_GPUPresentMode;
+
+        SDL_Window* window_{nullptr};
+        SDL_GPUDevice* device_{nullptr};
+        SDL_GPUShader* vertex_shader_{nullptr};
+        SDL_GPUShader* fragment_shader_{nullptr};
+        SDL_GPUGraphicsPipeline* pipeline_{nullptr};
+
+        bool vsync_{true};
+        std::string driver_name_;
+    };
+
+}  // namespace Rendering

src/rendering/sdl3gpu/shader_factory.hpp

@@ -0,0 +1,41 @@
+#pragma once
+
+#include <SDL3/SDL.h>
+
+#include <filesystem>
+
+namespace Rendering::Sdl3Gpu {
+
+    // Loads a compiled shader binary or source from disk and creates an SDL_GPUShader.
+    // For SPIR-V: pass the .spv path with format = SDL_GPU_SHADERFORMAT_SPIRV.
+    // For MSL: pass the .msl text path with format = SDL_GPU_SHADERFORMAT_MSL.
+    inline auto loadShaderFromFile(SDL_GPUDevice* device,
+        const std::filesystem::path& path,
+        SDL_GPUShaderFormat format,
+        const char* entrypoint,
+        SDL_GPUShaderStage stage,
+        Uint32 num_samplers,
+        Uint32 num_uniform_buffers) -> SDL_GPUShader* {
+        std::size_t size = 0;
+        void* data = SDL_LoadFile(path.string().c_str(), &size);
+        if (data == nullptr) {
+            return nullptr;
+        }
+
+        SDL_GPUShaderCreateInfo info{};
+        info.code_size = size;
+        info.code = static_cast<Uint8*>(data);
+        info.entrypoint = entrypoint;
+        info.format = format;
+        info.stage = stage;
+        info.num_samplers = num_samplers;
+        info.num_storage_textures = 0;
+        info.num_storage_buffers = 0;
+        info.num_uniform_buffers = num_uniform_buffers;
+
+        SDL_GPUShader* shader = SDL_CreateGPUShader(device, &info);
+        SDL_free(data);
+        return shader;
+    }
+
+}  // namespace Rendering::Sdl3Gpu

src/rendering/shader_backend.cpp

@@ -0,0 +1,99 @@
+#include "rendering/shader_backend.hpp"
+
+#include <algorithm>
+#include <fstream>
+#include <sstream>
+
+namespace Rendering {
+
+    namespace {
+
+        auto trimString(const std::string& str) -> std::string {
+            const std::size_t start = str.find_first_not_of(" \t\r\n");
+            const std::size_t end = str.find_last_not_of(" \t\r\n");
+            if (start != std::string::npos && end != std::string::npos) {
+                return str.substr(start, end - start + 1);
+            }
+            return "";
+        }
+
+    }  // namespace
+
+    auto loadFileToString(const std::filesystem::path& path, std::string& out) -> bool {
+        std::ifstream ifs(path, std::ios::in | std::ios::binary);
+        if (!ifs) { return false; }
+        std::ostringstream ss;
+        ss << ifs.rdbuf();
+        out = ss.str();
+        return true;
+    }
+
+    auto parseMetaFile(const std::filesystem::path& meta_path) -> ShaderMetadata {
+        ShaderMetadata metadata;
+        std::ifstream ifs(meta_path);
+        if (!ifs) { return metadata; }
+
+        std::string line;
+        while (std::getline(ifs, line)) {
+            const std::size_t colon = line.find(':');
+            if (colon == std::string::npos) { continue; }
+
+            std::string key = line.substr(0, colon);
+            std::string value = trimString(line.substr(colon + 1));
+
+            std::transform(key.begin(), key.end(), key.begin(),
+                [](unsigned char c) { return static_cast<char>(std::tolower(c)); });
+            key = trimString(key);
+
+            if (key == "name") { metadata.name = value; }
+            else if (key == "author") { metadata.author = value; }
+            else if (key == "ichannel0") { metadata.iChannel0 = value; }
+            else if (key == "ichannel1") { metadata.iChannel1 = value; }
+            else if (key == "ichannel2") { metadata.iChannel2 = value; }
+            else if (key == "ichannel3") { metadata.iChannel3 = value; }
+        }
+        return metadata;
+    }
+
+    auto extractShaderMetadata(const std::string& source) -> ShaderMetadata {
+        ShaderMetadata metadata;
+
+        std::istringstream stream(source);
+        std::string line;
+        int line_count = 0;
+        constexpr int MAX_LINES_TO_CHECK = 30;
+
+        while (std::getline(stream, line) && line_count < MAX_LINES_TO_CHECK) {
+            line_count++;
+
+            const std::size_t pos = line.find("//");
+            if (pos == std::string::npos) { continue; }
+
+            const std::string comment = line.substr(pos + 2);
+            std::string lower = comment;
+            std::transform(lower.begin(), lower.end(), lower.begin(),
+                [](unsigned char c) { return static_cast<char>(std::tolower(c)); });
+
+            auto valueAfterColon = [&]() {
+                return trimString(comment.substr(comment.find(':') + 1));
+            };
+
+            if (lower.find("name:") != std::string::npos) {
+                metadata.name = valueAfterColon();
+            } else if (lower.find("author:") != std::string::npos) {
+                metadata.author = valueAfterColon();
+            } else if (lower.find("ichannel0:") != std::string::npos) {
+                metadata.iChannel0 = valueAfterColon();
+            } else if (lower.find("ichannel1:") != std::string::npos) {
+                metadata.iChannel1 = valueAfterColon();
+            } else if (lower.find("ichannel2:") != std::string::npos) {
+                metadata.iChannel2 = valueAfterColon();
+            } else if (lower.find("ichannel3:") != std::string::npos) {
+                metadata.iChannel3 = valueAfterColon();
+            }
+        }
+
+        return metadata;
+    }
+
+}  // namespace Rendering

src/rendering/shader_backend.hpp

@@ -0,0 +1,57 @@
+#pragma once
+
+#include <SDL3/SDL.h>
+
+#include <filesystem>
+#include <memory>
+#include <string>
+
+namespace Rendering {
+
+    struct ShaderMetadata {
+        std::string name;
+        std::string author;
+        std::string iChannel0{"none"};
+        std::string iChannel1{"none"};
+        std::string iChannel2{"none"};
+        std::string iChannel3{"none"};
+    };
+
+    struct ShaderUniforms {
+        float iTime{0.0f};
+        float iResolutionX{0.0f};
+        float iResolutionY{0.0f};
+    };
+
+    struct ShaderProgramSpec {
+        std::filesystem::path folder;
+        std::string base_name;
+        ShaderMetadata metadata;
+    };
+
+    class IShaderBackend {
+       public:
+        IShaderBackend() = default;
+        virtual ~IShaderBackend() = default;
+
+        IShaderBackend(const IShaderBackend&) = delete;
+        IShaderBackend(IShaderBackend&&) = delete;
+        auto operator=(const IShaderBackend&) -> IShaderBackend& = delete;
+        auto operator=(IShaderBackend&&) -> IShaderBackend& = delete;
+
+        virtual auto init(SDL_Window* window) -> bool = 0;
+        virtual auto loadShader(const ShaderProgramSpec& spec) -> bool = 0;
+        virtual void render(const ShaderUniforms& uniforms) = 0;
+        virtual void setVSync(bool vsync) = 0;
+        virtual void cleanup() = 0;
+        [[nodiscard]] virtual auto driverName() const -> std::string = 0;
+    };
+
+    [[nodiscard]] auto makeOpenGLBackend() -> std::unique_ptr<IShaderBackend>;
+    [[nodiscard]] auto makeSdl3GpuBackend() -> std::unique_ptr<IShaderBackend>;
+
+    [[nodiscard]] auto extractShaderMetadata(const std::string& source) -> ShaderMetadata;
+    [[nodiscard]] auto loadFileToString(const std::filesystem::path& path, std::string& out) -> bool;
+    [[nodiscard]] auto parseMetaFile(const std::filesystem::path& meta_path) -> ShaderMetadata;
+
+}  // namespace Rendering

tools/shaders/compile_shaders.cmake

@@ -0,0 +1,70 @@
+# compile_shaders.cmake — invoked via `cmake -P`.
+#
+# Required cache vars:
+#   GLSLC       — path to the glslc executable.
+#   SHADERS_DIR — path to the shaders/ directory.
+#
+# Walks SHADERS_DIR for:
+#   _common/passthrough.vk.glsl         -> _common/passthrough.vert.spv
+#   <name>/<name>.vk.glsl               -> <name>/<name>.frag.spv
+#
+# Shaders are recompiled only if the .spv is missing or older than its source.
+
+if(NOT GLSLC)
+    message(FATAL_ERROR "compile_shaders.cmake: GLSLC not provided")
+endif()
+if(NOT SHADERS_DIR)
+    message(FATAL_ERROR "compile_shaders.cmake: SHADERS_DIR not provided")
+endif()
+if(NOT EXISTS "${SHADERS_DIR}")
+    message(FATAL_ERROR "compile_shaders.cmake: SHADERS_DIR does not exist: ${SHADERS_DIR}")
+endif()
+
+function(_compile_to_spv SOURCE STAGE OUTPUT)
+    if(EXISTS "${OUTPUT}")
+        file(TIMESTAMP "${SOURCE}" SRC_T "%s")
+        file(TIMESTAMP "${OUTPUT}" OUT_T "%s")
+        if(NOT "${SRC_T}" STREQUAL "" AND NOT "${OUT_T}" STREQUAL "")
+            if(SRC_T LESS_EQUAL OUT_T)
+                return()
+            endif()
+        endif()
+    endif()
+    message(STATUS "glslc (${STAGE}) ${SOURCE} -> ${OUTPUT}")
+    execute_process(
+        COMMAND "${GLSLC}" "-fshader-stage=${STAGE}" "${SOURCE}" -o "${OUTPUT}"
+        RESULT_VARIABLE RC
+        OUTPUT_VARIABLE STDOUT
+        ERROR_VARIABLE STDERR
+    )
+    if(NOT RC EQUAL 0)
+        message(FATAL_ERROR "glslc failed for ${SOURCE}:\n${STDERR}")
+    endif()
+endfunction()
+
+set(VERT_SOURCE "${SHADERS_DIR}/_common/passthrough.vk.glsl")
+set(VERT_OUTPUT "${SHADERS_DIR}/_common/passthrough.vert.spv")
+if(EXISTS "${VERT_SOURCE}")
+    _compile_to_spv("${VERT_SOURCE}" "vert" "${VERT_OUTPUT}")
+else()
+    message(WARNING "Missing shared vertex shader: ${VERT_SOURCE}")
+endif()
+
+file(GLOB SHADER_DIRS LIST_DIRECTORIES true RELATIVE "${SHADERS_DIR}" "${SHADERS_DIR}/*")
+foreach(DIR ${SHADER_DIRS})
+    set(ABS_DIR "${SHADERS_DIR}/${DIR}")
+    if(NOT IS_DIRECTORY "${ABS_DIR}")
+        continue()
+    endif()
+    string(SUBSTRING "${DIR}" 0 1 FIRST_CHAR)
+    if(FIRST_CHAR STREQUAL "_" OR FIRST_CHAR STREQUAL ".")
+        continue()
+    endif()
+
+    set(VK_SOURCE "${ABS_DIR}/${DIR}.vk.glsl")
+    set(SPV_OUTPUT "${ABS_DIR}/${DIR}.frag.spv")
+
+    if(EXISTS "${VK_SOURCE}")
+        _compile_to_spv("${VK_SOURCE}" "frag" "${SPV_OUTPUT}")
+    endif()
+endforeach()