Presets PostFX carregats de shaders/postfx.yaml; Screen aplica params (v0.5.0)

source/core/rendering/screen.cpp

@@ -136,6 +136,12 @@ void Screen::createSdl() {
     SDL_SetTextureScaleMode(game_texture_, toSdlScaleMode(config_.texture_filter));
 }
 
+void Screen::applyPostFXParams(const Rendering::PostFXParams& params) {
+    if (shader_backend_ != nullptr) {
+        shader_backend_->setPostFXParams(params);
+    }
+}
+
 void Screen::clear(std::uint8_t r, std::uint8_t g, std::uint8_t b) {
     const std::uint32_t COLOR = (0xFFU << 24) | (static_cast<std::uint32_t>(r) << 16) | (static_cast<std::uint32_t>(g) << 8) | static_cast<std::uint32_t>(b);
     std::ranges::fill(canvas_, COLOR);

source/core/rendering/screen.hpp

@@ -44,6 +44,10 @@ class Screen {
     // i tanca el subsistema de vídeo. El Director el crida ABANS de SDL_Quit.
     void shutdown();
 
+    // Reenvia paràmetres PostFX al backend GPU. No-op si estem al path
+    // SDL_Renderer (fallback) o si encara no hi ha backend.
+    void applyPostFXParams(const Rendering::PostFXParams& params);
+
     void clear(std::uint8_t r = 0, std::uint8_t g = 0, std::uint8_t b = 0);
     void present();