imlementant supersampling

data/shaders/postfx.frag

@@ -22,6 +22,10 @@ layout(set = 3, binding = 0) uniform PostFXUniforms {
     float gamma_strength;
     float curvature;
     float bleeding;
+    float pixel_scale;   // physical pixels per logical pixel (vh / tex_height_)
+    float time;          // seconds since SDL init (for future animated effects)
+    float oversample;    // supersampling factor (1.0 = off, 3.0 = 3×SS)
+    float pad1;          // padding — 48 bytes total (3 × 16)
 } u;
 
 // YCbCr helpers for NTSC bleeding
@@ -64,15 +68,17 @@ void main() {
     // Muestra base
     vec3 base = texture(scene, uv).rgb;
 
-    // Sangrado NTSC — difuminado horizontal de crominancia
+    // Sangrado NTSC — difuminado horizontal de crominancia.
+    // step = 1 pixel lógico de juego en UV (corrige SS: textureSize.x = game_w * oversample).
     vec3 colour;
     if (u.bleeding > 0.0) {
-        float tw = float(textureSize(scene, 0).x);
+        float tw   = float(textureSize(scene, 0).x);
+        float step = u.oversample / tw;  // 1 pixel lógico en UV
         vec3 ycc    = rgb_to_ycc(base);
-        vec3 ycc_l2 = rgb_to_ycc(texture(scene, uv - vec2(2.0/tw, 0.0)).rgb);
-        vec3 ycc_l1 = rgb_to_ycc(texture(scene, uv - vec2(1.0/tw, 0.0)).rgb);
-        vec3 ycc_r1 = rgb_to_ycc(texture(scene, uv + vec2(1.0/tw, 0.0)).rgb);
-        vec3 ycc_r2 = rgb_to_ycc(texture(scene, uv + vec2(2.0/tw, 0.0)).rgb);
+        vec3 ycc_l2 = rgb_to_ycc(texture(scene, uv - vec2(2.0*step, 0.0)).rgb);
+        vec3 ycc_l1 = rgb_to_ycc(texture(scene, uv - vec2(1.0*step, 0.0)).rgb);
+        vec3 ycc_r1 = rgb_to_ycc(texture(scene, uv + vec2(1.0*step, 0.0)).rgb);
+        vec3 ycc_r2 = rgb_to_ycc(texture(scene, uv + vec2(2.0*step, 0.0)).rgb);
         ycc.yz = (ycc_l2.yz + ycc_l1.yz*2.0 + ycc.yz*2.0 + ycc_r1.yz*2.0 + ycc_r2.yz) / 8.0;
         colour = mix(base, ycc_to_rgb(ycc), u.bleeding);
     } else {
@@ -90,14 +96,19 @@ void main() {
         colour = mix(colour, lin, u.gamma_strength);
     }
 
-    // Scanlines
-    float texHeight  = float(textureSize(scene, 0).y);
-    float scaleY     = u.screen_height / texHeight;
-    float screenY    = uv.y * u.screen_height;
-    float posInRow   = mod(screenY, scaleY);
-    float scanLineDY = posInRow / scaleY - 0.5;
-    float scan       = max(1.0 - scanLineDY * scanLineDY * 6.0, 0.12) * 3.5;
-    colour *= mix(1.0, 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 > 0.0) {
+        float ps          = max(1.0, 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 - 1.0, row_pos);
+        float scan        = mix(3.5, 0.42, is_dark);
+        colour           *= mix(1.0, scan, u.scanline_strength);
+    }
 
     if (u.gamma_strength > 0.0) {
         vec3 enc = pow(colour, vec3(1.0 / 2.2));
@@ -109,7 +120,8 @@ void main() {
     float vignette = 1.0 - dot(d, d) * u.vignette_strength;
     colour *= clamp(vignette, 0.0, 1.0);
 
-    // 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 > 0.0) {
         float whichMask = fract(gl_FragCoord.x * 0.3333333);
         vec3 mask = vec3(0.80);

source/core/rendering/screen.cpp

@@ -463,7 +463,10 @@ auto loadData(const std::string& filepath) -> std::vector<uint8_t> {
 void Screen::applyCurrentPostFXPreset() {
     if (shader_backend_ && !Options::postfx_presets.empty()) {
         const auto& p = Options::postfx_presets[static_cast<size_t>(Options::current_postfx_preset)];
-        Rendering::PostFXParams params{.vignette = p.vignette, .scanlines = p.scanlines, .chroma = p.chroma, .mask = p.mask, .gamma = p.gamma, .curvature = p.curvature, .bleeding = p.bleeding};
+        // setOversample primero: puede recrear texturas y debe conocer el factor
+        // antes de que setPostFXParams decida si hornear scanlines en CPU o GPU.
+        shader_backend_->setOversample(p.supersampling ? 3 : 1);
+        Rendering::PostFXParams params{.vignette = p.vignette, .scanlines = p.scanlines, .chroma = p.chroma, .mask = p.mask, .gamma = p.gamma, .curvature = p.curvature, .bleeding = p.bleeding, .supersampling = p.supersampling};
         shader_backend_->setPostFXParams(params);
     }
 }

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 oversample;  // 1.0 = sin SS, 3.0 = 3× supersampling
+    float pad1;
 };
 
 // YCbCr helpers for NTSC bleeding
@@ -98,15 +102,17 @@ fragment float4 postfx_fs(PostVOut                 in    [[stage_in]],
     // Muestra base
     float3 base = scene.sample(samp, uv).rgb;
 
-    // Sangrado NTSC — difuminado horizontal de crominancia
+    // Sangrado NTSC — difuminado horizontal de crominancia.
+    // step = 1 pixel de juego en espacio UV (corrige SS: scene.get_width() = game_w * oversample).
     float3 colour;
     if (u.bleeding > 0.0f) {
-        float tw = float(scene.get_width());
-        float3 ycc   = rgb_to_ycc(base);
-        float3 ycc_l2 = rgb_to_ycc(scene.sample(samp, uv - float2(2.0f/tw, 0.0f)).rgb);
-        float3 ycc_l1 = rgb_to_ycc(scene.sample(samp, uv - float2(1.0f/tw, 0.0f)).rgb);
-        float3 ycc_r1 = rgb_to_ycc(scene.sample(samp, uv + float2(1.0f/tw, 0.0f)).rgb);
-        float3 ycc_r2 = rgb_to_ycc(scene.sample(samp, uv + float2(2.0f/tw, 0.0f)).rgb);
+        float tw    = float(scene.get_width());
+        float step  = u.oversample / tw;  // 1 pixel lógico en UV
+        float3 ycc    = rgb_to_ycc(base);
+        float3 ycc_l2 = rgb_to_ycc(scene.sample(samp, uv - float2(2.0f*step, 0.0f)).rgb);
+        float3 ycc_l1 = rgb_to_ycc(scene.sample(samp, uv - float2(1.0f*step, 0.0f)).rgb);
+        float3 ycc_r1 = rgb_to_ycc(scene.sample(samp, uv + float2(1.0f*step, 0.0f)).rgb);
+        float3 ycc_r2 = rgb_to_ycc(scene.sample(samp, uv + float2(2.0f*step, 0.0f)).rgb);
         ycc.yz = (ycc_l2.yz + ycc_l1.yz*2.0f + ycc.yz*2.0f + ycc_r1.yz*2.0f + ycc_r2.yz) / 8.0f;
         colour = mix(base, ycc_to_rgb(ycc), u.bleeding);
     } else {
@@ -124,14 +130,19 @@ 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 +154,8 @@ 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);
@@ -189,9 +201,12 @@ namespace Rendering {
         float fw = 0.0F;
         float fh = 0.0F;
         SDL_GetTextureSize(texture, &fw, &fh);
-        tex_width_ = static_cast<int>(fw);
-        tex_height_ = static_cast<int>(fh);
-        uniforms_.screen_height = fh;  // Altura lógica del juego (no el swapchain físico)
+        game_width_  = static_cast<int>(fw);
+        game_height_ = static_cast<int>(fh);
+        tex_width_   = game_width_  * oversample_;
+        tex_height_  = game_height_ * oversample_;
+        uniforms_.screen_height = static_cast<float>(tex_height_);  // Altura de la textura GPU
+        uniforms_.oversample    = static_cast<float>(oversample_);
 
         // ----------------------------------------------------------------
         // 1. Create GPU device (solo si no existe ya)
@@ -254,7 +269,7 @@ namespace Rendering {
         }
 
         // ----------------------------------------------------------------
-        // 5. Create nearest-neighbour sampler (retro pixel art)
+        // 5. Create samplers: NEAREST (pixel art) + LINEAR (supersampling)
         // ----------------------------------------------------------------
         SDL_GPUSamplerCreateInfo samp_info = {};
         samp_info.min_filter = SDL_GPU_FILTER_NEAREST;
@@ -270,6 +285,20 @@ namespace Rendering {
             return false;
         }
 
+        SDL_GPUSamplerCreateInfo lsamp_info = {};
+        lsamp_info.min_filter = SDL_GPU_FILTER_LINEAR;
+        lsamp_info.mag_filter = SDL_GPU_FILTER_LINEAR;
+        lsamp_info.mipmap_mode = SDL_GPU_SAMPLERMIPMAPMODE_NEAREST;
+        lsamp_info.address_mode_u = SDL_GPU_SAMPLERADDRESSMODE_CLAMP_TO_EDGE;
+        lsamp_info.address_mode_v = SDL_GPU_SAMPLERADDRESSMODE_CLAMP_TO_EDGE;
+        lsamp_info.address_mode_w = SDL_GPU_SAMPLERADDRESSMODE_CLAMP_TO_EDGE;
+        linear_sampler_ = SDL_CreateGPUSampler(device_, &lsamp_info);
+        if (linear_sampler_ == nullptr) {
+            SDL_Log("SDL3GPUShader: failed to create linear sampler: %s", SDL_GetError());
+            cleanup();
+            return false;
+        }
+
         // ----------------------------------------------------------------
         // 6. Create PostFX graphics pipeline
         // ----------------------------------------------------------------
@@ -335,7 +364,9 @@ namespace Rendering {
     }
 
     // ---------------------------------------------------------------------------
-    // uploadPixels — copies ARGB8888 CPU pixels into the GPU transfer buffer
+    // uploadPixels — copies ARGB8888 CPU pixels into the GPU transfer buffer.
+    // Con supersampling (oversample_ > 1) expande cada pixel del juego a un bloque
+    // oversample × oversample y hornea la scanline oscura en la última fila del bloque.
     // ---------------------------------------------------------------------------
     void SDL3GPUShader::uploadPixels(const Uint32* pixels, int width, int height) {
         if (!is_initialized_ || (upload_buffer_ == nullptr)) { return; }
@@ -345,7 +376,45 @@ namespace Rendering {
             SDL_Log("SDL3GPUShader: SDL_MapGPUTransferBuffer failed: %s", SDL_GetError());
             return;
         }
-        std::memcpy(mapped, pixels, static_cast<size_t>(width * height * 4));
+
+        if (oversample_ <= 1) {
+            // Path sin supersampling: copia directa
+            std::memcpy(mapped, pixels, static_cast<size_t>(width * height * 4));
+        } else {
+            // Path con supersampling: expande cada pixel a OS×OS, oscurece última fila.
+            // Replica la fórmula del shader: mix(3.5, 0.42, scanline_strength).
+            auto* out = static_cast<Uint32*>(mapped);
+            const int OS = oversample_;
+            const float BRIGHT_MUL = 1.0F + (baked_scanline_strength_ * 2.5F);   // rows 0..OS-2
+            const float DARK_MUL   = 1.0F - (baked_scanline_strength_ * 0.58F);  // row OS-1
+
+            for (int y = 0; y < height; ++y) {
+                for (int x = 0; x < width; ++x) {
+                    const Uint32 SRC   = pixels[y * width + x];
+                    const Uint32 ALPHA = (SRC >> 24) & 0xFFU;
+                    const auto   FR    = static_cast<float>((SRC >> 16) & 0xFFU);
+                    const auto   FG    = static_cast<float>((SRC >>  8) & 0xFFU);
+                    const auto   FB    = static_cast<float>( SRC        & 0xFFU);
+
+                    auto make_px = [ALPHA](float rv, float gv, float bv) -> Uint32 {
+                        auto cl = [](float v) -> Uint32 { return static_cast<Uint32>(std::min(255.0F, v)); };
+                        return (ALPHA << 24) | (cl(rv) << 16) | (cl(gv) << 8) | cl(bv);
+                    };
+
+                    const Uint32 BRIGHT = make_px(FR * BRIGHT_MUL, FG * BRIGHT_MUL, FB * BRIGHT_MUL);
+                    const Uint32 DARK   = make_px(FR * DARK_MUL,   FG * DARK_MUL,   FB * DARK_MUL);
+
+                    for (int dy = 0; dy < OS; ++dy) {
+                        const Uint32 OUT_PX = (dy == OS - 1) ? DARK : BRIGHT;
+                        const int DST_Y = (y * OS) + dy;
+                        for (int dx = 0; dx < OS; ++dx) {
+                            out[DST_Y * (width * OS) + (x * OS) + dx] = OUT_PX;
+                        }
+                    }
+                }
+            }
+        }
+
         SDL_UnmapGPUTransferBuffer(device_, upload_buffer_);
     }
 
@@ -406,30 +475,45 @@ namespace Rendering {
         if (pass != nullptr) {
             SDL_BindGPUGraphicsPipeline(pass, pipeline_);
 
-            // Calcular viewport para mantener relación de aspecto (letterbox o integer scale)
+            // Calcular viewport usando las dimensiones lógicas del canvas (game_width_/height_),
+            // no las de la textura GPU (que pueden ser game×3 con supersampling).
+            // El GPU escala la textura para cubrir el viewport independientemente de su resolución.
             float vx = 0.0F;
             float vy = 0.0F;
             float vw = 0.0F;
             float vh = 0.0F;
             if (integer_scale_) {
-                const int SCALE = std::max(1, std::min(static_cast<int>(sw) / tex_width_, static_cast<int>(sh) / tex_height_));
-                vw = static_cast<float>(tex_width_ * SCALE);
-                vh = static_cast<float>(tex_height_ * SCALE);
+                const int SCALE = std::max(1, std::min(static_cast<int>(sw) / game_width_, static_cast<int>(sh) / game_height_));
+                vw = static_cast<float>(game_width_ * SCALE);
+                vh = static_cast<float>(game_height_ * SCALE);
             } else {
                 const float SCALE = std::min(
-                    static_cast<float>(sw) / static_cast<float>(tex_width_),
-                    static_cast<float>(sh) / static_cast<float>(tex_height_));
-                vw = static_cast<float>(tex_width_) * SCALE;
-                vh = static_cast<float>(tex_height_) * SCALE;
+                    static_cast<float>(sw) / static_cast<float>(game_width_),
+                    static_cast<float>(sh) / static_cast<float>(game_height_));
+                vw = static_cast<float>(game_width_) * SCALE;
+                vh = static_cast<float>(game_height_) * SCALE;
             }
             vx = std::floor((static_cast<float>(sw) - vw) * 0.5F);
             vy = std::floor((static_cast<float>(sh) - vh) * 0.5F);
             SDL_GPUViewport vp = {vx, vy, vw, vh, 0.0F, 1.0F};
             SDL_SetGPUViewport(pass, &vp);
 
+            // pixel_scale: pixels físicos por pixel lógico de juego (para scanlines sin SS).
+            // Con SS las scanlines están horneadas en CPU → scanline_strength=0 → no se usa.
+            uniforms_.pixel_scale = (game_height_ > 0)
+                ? (vh / static_cast<float>(game_height_))
+                : 1.0F;
+            uniforms_.time      = static_cast<float>(SDL_GetTicks()) / 1000.0F;
+            uniforms_.oversample = static_cast<float>(oversample_);
+
+            // Con supersampling usamos LINEAR para que el escalado a zooms no-múltiplo-de-3
+            // promedia correctamente las filas de scanline horneadas en CPU.
+            SDL_GPUSampler* active_sampler = (oversample_ > 1 && linear_sampler_ != nullptr)
+                ? linear_sampler_ : sampler_;
+
             SDL_GPUTextureSamplerBinding binding = {};
             binding.texture = scene_texture_;
-            binding.sampler = sampler_;
+            binding.sampler = active_sampler;
             SDL_BindGPUFragmentSamplers(pass, 0, &binding, 1);
 
             SDL_PushGPUFragmentUniformData(cmd, 0, &uniforms_, sizeof(PostFXUniforms));
@@ -466,6 +550,10 @@ namespace Rendering {
                 SDL_ReleaseGPUSampler(device_, sampler_);
                 sampler_ = nullptr;
             }
+            if (linear_sampler_ != nullptr) {
+                SDL_ReleaseGPUSampler(device_, linear_sampler_);
+                linear_sampler_ = nullptr;
+            }
             // device_ y el claim de la ventana se mantienen vivos
         }
     }
@@ -534,12 +622,16 @@ namespace Rendering {
 
     void SDL3GPUShader::setPostFXParams(const PostFXParams& p) {
         uniforms_.vignette_strength = p.vignette;
-        uniforms_.scanline_strength = p.scanlines;
-        uniforms_.chroma_strength = p.chroma;
-        uniforms_.mask_strength = p.mask;
-        uniforms_.gamma_strength = p.gamma;
-        uniforms_.curvature = p.curvature;
-        uniforms_.bleeding = p.bleeding;
+        uniforms_.chroma_strength   = p.chroma;
+        uniforms_.mask_strength     = p.mask;
+        uniforms_.gamma_strength    = p.gamma;
+        uniforms_.curvature         = p.curvature;
+        uniforms_.bleeding          = p.bleeding;
+
+        // Con supersampling las scanlines se hornean en CPU (uploadPixels).
+        // El shader recibe strength=0 para no aplicarlas de nuevo en GPU.
+        baked_scanline_strength_ = p.scanlines;
+        uniforms_.scanline_strength = (oversample_ > 1) ? 0.0F : p.scanlines;
     }
 
     void SDL3GPUShader::setVSync(bool vsync) {
@@ -553,4 +645,68 @@ namespace Rendering {
         integer_scale_ = integer_scale;
     }
 
+    // ---------------------------------------------------------------------------
+    // setOversample — cambia el factor SS; recrea texturas si ya está inicializado
+    // ---------------------------------------------------------------------------
+    void SDL3GPUShader::setOversample(int factor) {
+        const int NEW_FACTOR = std::max(1, factor);
+        if (NEW_FACTOR == oversample_) { return; }
+        oversample_ = NEW_FACTOR;
+        if (is_initialized_) {
+            reinitTexturesAndBuffer();
+            // scanline_strength se actualizará en el próximo setPostFXParams
+        }
+    }
+
+    // ---------------------------------------------------------------------------
+    // reinitTexturesAndBuffer — recrea scene_texture_ y upload_buffer_ con el
+    // tamaño actual (game × oversample_). No toca pipeline ni samplers.
+    // ---------------------------------------------------------------------------
+    auto SDL3GPUShader::reinitTexturesAndBuffer() -> bool {
+        if (device_ == nullptr) { return false; }
+        SDL_WaitForGPUIdle(device_);
+
+        if (scene_texture_ != nullptr) {
+            SDL_ReleaseGPUTexture(device_, scene_texture_);
+            scene_texture_ = nullptr;
+        }
+        if (upload_buffer_ != nullptr) {
+            SDL_ReleaseGPUTransferBuffer(device_, upload_buffer_);
+            upload_buffer_ = nullptr;
+        }
+
+        tex_width_  = game_width_  * oversample_;
+        tex_height_ = game_height_ * oversample_;
+        uniforms_.screen_height = static_cast<float>(tex_height_);
+        uniforms_.oversample    = static_cast<float>(oversample_);
+
+        SDL_GPUTextureCreateInfo tex_info = {};
+        tex_info.type   = SDL_GPU_TEXTURETYPE_2D;
+        tex_info.format = SDL_GPU_TEXTUREFORMAT_B8G8R8A8_UNORM;
+        tex_info.usage  = SDL_GPU_TEXTUREUSAGE_SAMPLER;
+        tex_info.width  = static_cast<Uint32>(tex_width_);
+        tex_info.height = static_cast<Uint32>(tex_height_);
+        tex_info.layer_count_or_depth = 1;
+        tex_info.num_levels = 1;
+        scene_texture_ = SDL_CreateGPUTexture(device_, &tex_info);
+        if (scene_texture_ == nullptr) {
+            SDL_Log("SDL3GPUShader: reinit — failed to create scene texture: %s", SDL_GetError());
+            return false;
+        }
+
+        SDL_GPUTransferBufferCreateInfo tb_info = {};
+        tb_info.usage = SDL_GPU_TRANSFERBUFFERUSAGE_UPLOAD;
+        tb_info.size  = static_cast<Uint32>(tex_width_ * tex_height_ * 4);
+        upload_buffer_ = SDL_CreateGPUTransferBuffer(device_, &tb_info);
+        if (upload_buffer_ == nullptr) {
+            SDL_Log("SDL3GPUShader: reinit — failed to create upload buffer: %s", SDL_GetError());
+            SDL_ReleaseGPUTexture(device_, scene_texture_);
+            scene_texture_ = nullptr;
+            return false;
+        }
+
+        SDL_Log("SDL3GPUShader: oversample %d → texture %dx%d", oversample_, tex_width_, tex_height_);
+        return true;
+    }
+
 }  // namespace Rendering

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 oversample;         // supersampling factor (1.0 = off, 3.0 = 3×SS)
+    float pad1;               // padding — keep struct at 48 bytes (3 × 16)
 };
 
 namespace Rendering {
@@ -56,6 +60,9 @@ namespace Rendering {
         // Activa/desactiva escalado entero (integer scale)
         void setScaleMode(bool integer_scale) override;
 
+        // Establece factor de supersampling (1 = off, 3 = 3×SS)
+        void setOversample(int factor) override;
+
        private:
         static auto createShaderMSL(SDL_GPUDevice* device,
             const char* msl_source,
@@ -73,18 +80,24 @@ namespace Rendering {
             Uint32 num_uniform_buffers) -> SDL_GPUShader*;
 
         auto createPipeline() -> bool;
+        auto reinitTexturesAndBuffer() -> bool;  // Recrea textura y buffer con oversample actual
 
         SDL_Window* window_ = nullptr;
         SDL_GPUDevice* device_ = nullptr;
         SDL_GPUGraphicsPipeline* pipeline_ = nullptr;
         SDL_GPUTexture* scene_texture_ = nullptr;
         SDL_GPUTransferBuffer* upload_buffer_ = nullptr;
-        SDL_GPUSampler* sampler_ = nullptr;
+        SDL_GPUSampler* sampler_ = nullptr;         // NEAREST — para path sin supersampling
+        SDL_GPUSampler* linear_sampler_ = nullptr;  // LINEAR — para path con supersampling
 
-        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, .oversample = 1.0F};
 
-        int tex_width_ = 0;
+        int game_width_ = 0;   // Dimensiones originales del canvas (sin SS)
+        int game_height_ = 0;
+        int tex_width_ = 0;    // Dimensiones de la textura GPU (game × oversample_)
         int tex_height_ = 0;
+        int oversample_ = 1;              // Factor SS actual (1 o 3)
+        float baked_scanline_strength_ = 0.0F;  // Guardado para hornear en CPU
         bool is_initialized_ = false;
         bool vsync_ = true;
         bool integer_scale_ = false;

source/core/rendering/shader_backend.hpp

@@ -11,13 +11,14 @@ namespace Rendering {
      * Definido a nivel de namespace para facilitar el uso desde subclases y screen.cpp
      */
     struct PostFXParams {
-        float vignette = 0.0F;   // Intensidad de la viñeta
-        float scanlines = 0.0F;  // Intensidad de las scanlines
-        float chroma = 0.0F;     // Aberración cromática
-        float mask = 0.0F;       // Máscara de fósforo RGB
-        float gamma = 0.0F;      // Corrección gamma (blend 0=off, 1=full)
-        float curvature = 0.0F;  // Curvatura barrel CRT
-        float bleeding = 0.0F;   // Sangrado de color NTSC
+        float vignette = 0.0F;    // Intensidad de la viñeta
+        float scanlines = 0.0F;   // Intensidad de las scanlines
+        float chroma = 0.0F;      // Aberración cromática
+        float mask = 0.0F;        // Máscara de fósforo RGB
+        float gamma = 0.0F;       // Corrección gamma (blend 0=off, 1=full)
+        float curvature = 0.0F;   // Curvatura barrel CRT
+        float bleeding = 0.0F;    // Sangrado de color NTSC
+        bool supersampling{false}; // Supersampling 3×: scanlines horneadas en CPU + sampler LINEAR
     };
 
     /**
@@ -82,6 +83,13 @@ namespace Rendering {
          */
         virtual void setScaleMode(bool /*integer_scale*/) {}
 
+        /**
+         * @brief Establece el factor de supersampling (1 = off, 3 = 3× SS)
+         * Con factor > 1, la textura GPU se crea a game×factor resolución y
+         * las scanlines se hornean en CPU (uploadPixels). El sampler usa LINEAR.
+         */
+        virtual void setOversample(int /*factor*/) {}
+
         /**
          * @brief Verifica si el backend está usando aceleración por hardware
          * @return true si usa aceleración (OpenGL/Metal/Vulkan)

source/game/options.cpp

@@ -718,6 +718,9 @@ namespace Options {
                     parseFloatField(p, "gamma", preset.gamma);
                     parseFloatField(p, "curvature", preset.curvature);
                     parseFloatField(p, "bleeding", preset.bleeding);
+                    if (p.contains("supersampling")) {
+                        try { preset.supersampling = p["supersampling"].get_value<bool>(); } catch (...) {}
+                    }
                     postfx_presets.push_back(preset);
                 }
             }
@@ -759,6 +762,9 @@ namespace Options {
         file << "# gamma: gamma correction input 2.4 / output 2.2\n";
         file << "# curvature: CRT barrel distortion\n";
         file << "# bleeding: NTSC horizontal colour bleeding\n";
+        file << "# supersampling: 3x internal resolution, scanlines baked in CPU + linear filter\n";
+        file << "#   true  = consistent 33% scanlines at any zoom (slight softening at non-3x)\n";
+        file << "#   false = sharp pixel art, scanlines depend on zoom (33% at 3x, 25% at 4x)\n";
         file << "\n";
         file << "presets:\n";
         file << "  - name: \"CRT\"\n";
@@ -769,6 +775,16 @@ namespace Options {
         file << "    gamma: 0.8\n";
         file << "    curvature: 0.0\n";
         file << "    bleeding: 0.0\n";
+        file << "    supersampling: false\n";
+        file << "  - name: \"CRT-SS\"\n";
+        file << "    vignette: 0.6\n";
+        file << "    scanlines: 0.7\n";
+        file << "    chroma: 0.15\n";
+        file << "    mask: 0.6\n";
+        file << "    gamma: 0.8\n";
+        file << "    curvature: 0.0\n";
+        file << "    bleeding: 0.0\n";
+        file << "    supersampling: true\n";
         file << "  - name: \"NTSC\"\n";
         file << "    vignette: 0.4\n";
         file << "    scanlines: 0.5\n";
@@ -777,6 +793,7 @@ namespace Options {
         file << "    gamma: 0.5\n";
         file << "    curvature: 0.0\n";
         file << "    bleeding: 0.6\n";
+        file << "    supersampling: false\n";
         file << "  - name: \"CURVED\"\n";
         file << "    vignette: 0.5\n";
         file << "    scanlines: 0.6\n";
@@ -785,6 +802,7 @@ namespace Options {
         file << "    gamma: 0.7\n";
         file << "    curvature: 0.8\n";
         file << "    bleeding: 0.0\n";
+        file << "    supersampling: false\n";
         file << "  - name: \"SCANLINES\"\n";
         file << "    vignette: 0.0\n";
         file << "    scanlines: 0.8\n";
@@ -793,6 +811,7 @@ namespace Options {
         file << "    gamma: 0.0\n";
         file << "    curvature: 0.0\n";
         file << "    bleeding: 0.0\n";
+        file << "    supersampling: false\n";
         file << "  - name: \"SUBTLE\"\n";
         file << "    vignette: 0.3\n";
         file << "    scanlines: 0.4\n";
@@ -801,6 +820,7 @@ namespace Options {
         file << "    gamma: 0.3\n";
         file << "    curvature: 0.0\n";
         file << "    bleeding: 0.0\n";
+        file << "    supersampling: false\n";
 
         file.close();
 

source/game/options.hpp

@@ -116,14 +116,15 @@ namespace Options {
 
     // Estructura para un preset de PostFX
     struct PostFXPreset {
-        std::string name;       // Nombre del preset
-        float vignette{0.6F};   // Intensidad de la viñeta (0.0 = ninguna, 1.0 = máxima)
-        float scanlines{0.7F};  // Intensidad de las scanlines (0.0 = desactivadas, 1.0 = máximas)
-        float chroma{0.15F};    // Intensidad de la aberración cromática (0.0 = ninguna, 1.0 = máxima)
-        float mask{0.0F};       // Intensidad de la máscara de fósforo RGB (0.0 = desactivada, 1.0 = máxima)
-        float gamma{0.0F};      // Corrección gamma input 2.4 / output 2.2 (0.0 = off, 1.0 = plena)
-        float curvature{0.0F};  // Distorsión barrel CRT (0.0 = plana, 1.0 = máxima curvatura)
-        float bleeding{0.0F};   // Sangrado de color NTSC horizontal Y/C (0.0 = off, 1.0 = máximo)
+        std::string name;           // Nombre del preset
+        float vignette{0.6F};       // Intensidad de la viñeta (0.0 = ninguna, 1.0 = máxima)
+        float scanlines{0.7F};      // Intensidad de las scanlines (0.0 = desactivadas, 1.0 = máximas)
+        float chroma{0.15F};        // Intensidad de la aberración cromática (0.0 = ninguna, 1.0 = máxima)
+        float mask{0.0F};           // Intensidad de la máscara de fósforo RGB (0.0 = desactivada, 1.0 = máxima)
+        float gamma{0.0F};          // Corrección gamma input 2.4 / output 2.2 (0.0 = off, 1.0 = plena)
+        float curvature{0.0F};      // Distorsión barrel CRT (0.0 = plana, 1.0 = máxima curvatura)
+        float bleeding{0.0F};       // Sangrado de color NTSC horizontal Y/C (0.0 = off, 1.0 = máximo)
+        bool  supersampling{false}; // 3x supersampling: scanlines horneadas en CPU + sampler LINEAR
     };
 
     // --- Variables globales ---