deixant postfx al gust

source/core/rendering/sdl3gpu/sdl3gpu_shader.cpp

@@ -54,6 +54,10 @@ struct PostFXUniforms {
     float gamma_strength;
     float curvature;
     float bleeding;
+    float pixel_scale;
+    float time;
+    float pad0;
+    float pad1;
 };
 
 // YCbCr helpers for NTSC bleeding
@@ -124,14 +128,19 @@ fragment float4 postfx_fs(PostVOut                 in    [[stage_in]],
         colour = mix(colour, lin, u.gamma_strength);
     }
 
-    // Scanlines
-    float texHeight  = float(scene.get_height());
-    float scaleY     = u.screen_height / texHeight;
-    float screenY    = uv.y * u.screen_height;
-    float posInRow   = fmod(screenY, scaleY);
-    float scanLineDY = posInRow / scaleY - 0.5f;
-    float scan       = max(1.0f - scanLineDY * scanLineDY * 6.0f, 0.12f) * 3.5f;
-    colour *= mix(1.0f, scan, u.scanline_strength);
+    // Scanlines — 1 pixel físico oscuro por fila lógica.
+    // Usa uv.y (independiente del offset de letterbox) con pixel_scale para
+    // calcular la posición dentro de la fila en coordenadas físicas.
+    // 3x: 1 dark + 2 bright. 4x: 1 dark + 3 bright.
+    // bright=3.5×, dark floor=0.42 (mantiene aspecto CRT original).
+    if (u.scanline_strength > 0.0f) {
+        float ps          = max(1.0f, round(u.pixel_scale));
+        float frac_in_row = fract(uv.y * u.screen_height);
+        float row_pos     = floor(frac_in_row * ps);
+        float is_dark     = step(ps - 1.0f, row_pos);
+        float scan        = mix(3.5f, 0.42f, is_dark);
+        colour           *= mix(1.0f, scan, u.scanline_strength);
+    }
 
     if (u.gamma_strength > 0.0f) {
         float3 enc = pow(colour, float3(1.0f/2.2f));
@@ -143,7 +152,8 @@ fragment float4 postfx_fs(PostVOut                 in    [[stage_in]],
     float vignette = 1.0f - dot(d, d) * u.vignette_strength;
     colour *= clamp(vignette, 0.0f, 1.0f);
 
-    // Máscara de fósforo RGB
+    // Máscara de fósforo RGB — después de scanlines (orden original):
+    // filas brillantes saturadas → máscara invisible, filas oscuras → RGB visible.
     if (u.mask_strength > 0.0f) {
         float whichMask = fract(in.pos.x * 0.3333333f);
         float3 mask = float3(0.80f);
@@ -427,6 +437,12 @@ namespace Rendering {
             SDL_GPUViewport vp = {vx, vy, vw, vh, 0.0F, 1.0F};
             SDL_SetGPUViewport(pass, &vp);
 
+            // Uniforms dinámicos: pixel_scale y time
+            uniforms_.pixel_scale = (tex_height_ > 0)
+                ? (vh / static_cast<float>(tex_height_))
+                : 1.0F;
+            uniforms_.time = static_cast<float>(SDL_GetTicks()) / 1000.0F;
+
             SDL_GPUTextureSamplerBinding binding = {};
             binding.texture = scene_texture_;
             binding.sampler = sampler_;

source/core/rendering/sdl3gpu/sdl3gpu_shader.hpp

@@ -7,16 +7,20 @@
 
 // PostFX uniforms pushed to fragment stage each frame.
 // Must match the MSL struct and GLSL uniform block layout.
-// 8 floats = 32 bytes — meets Metal/Vulkan 16-byte alignment requirement.
+// 12 floats = 48 bytes — meets Metal/Vulkan 16-byte alignment requirement.
 struct PostFXUniforms {
     float vignette_strength;  // 0 = none, ~0.8 = subtle
     float chroma_strength;    // 0 = off, ~0.2 = subtle chromatic aberration
     float scanline_strength;  // 0 = off, 1 = full
-    float screen_height;      // logical height in pixels (for resolution-independent scanlines)
+    float screen_height;      // logical height in pixels (used by bleeding effect)
     float mask_strength;      // 0 = off, 1 = full phosphor dot mask
     float gamma_strength;     // 0 = off, 1 = full gamma 2.4/2.2 correction
     float curvature;          // 0 = flat, 1 = max barrel distortion
     float bleeding;           // 0 = off, 1 = max NTSC chrominance bleeding
+    float pixel_scale;        // physical pixels per logical pixel (vh / tex_height_)
+    float time;               // seconds since SDL init (SDL_GetTicks() / 1000.0f)
+    float pad0;               // padding — keep struct at 48 bytes (3 × 16)
+    float pad1;
 };
 
 namespace Rendering {
@@ -81,7 +85,7 @@ namespace Rendering {
         SDL_GPUTransferBuffer* upload_buffer_ = nullptr;
         SDL_GPUSampler* sampler_ = nullptr;
 
-        PostFXUniforms uniforms_{.vignette_strength = 0.6F, .chroma_strength = 0.15F, .scanline_strength = 0.7F, .screen_height = 192.0F};
+        PostFXUniforms uniforms_{.vignette_strength = 0.6F, .chroma_strength = 0.15F, .scanline_strength = 0.7F, .screen_height = 192.0F, .pixel_scale = 1.0F};
 
         int tex_width_ = 0;
         int tex_height_ = 0;