1 files changed, 52 insertions, 24 deletions

diff --git a/src/gpu/effect.h b/src/gpu/effect.h
index f92e3ef..5f49041 100644
--- a/src/gpu/effect.h
+++ b/src/gpu/effect.h
@@ -1,12 +1,11 @@
 // This file is part of the 64k demo project.
 // It defines the Effect interface and Sequence management system.
-// Used for choreographing visual effects.
 
 #pragma once
 
-#include <vector>
-#include <memory>
 #include <algorithm>
+#include <memory>
+#include <vector>
 
 #if defined(DEMO_CROSS_COMPILE_WIN32)
 #include <webgpu/webgpu.h>
@@ -15,6 +14,7 @@
 #endif
 
 class MainSequence;
+class PostProcessEffect;
 
 // Abstract base class for all visual effects
 class Effect {
@@ -22,7 +22,6 @@ public:
   virtual ~Effect() = default;
 
   // One-time setup (load assets, create buffers).
-  // Idempotent: safe to call multiple times if effect is shared.
   virtual void init(MainSequence *demo) { (void)demo; }
 
   // Called when the effect starts playing in a sequence segment.
@@ -44,8 +43,29 @@ public:
 
   // Called when the effect finishes in a sequence segment.
   virtual void end() {}
-  
+
   bool is_initialized = false;
+  virtual bool is_post_process() const { return false; }
+};
+
+// Base class for all post-processing effects
+class PostProcessEffect : public Effect {
+public:
+  bool is_post_process() const override { return true; }
+
+  // Post-process effects don't have a compute phase by default
+  void compute(WGPUCommandEncoder, float, float, float, float) override {}
+
+  // Fullscreen quad render
+  void render(WGPURenderPassEncoder pass, float time, float beat,
+              float intensity, float aspect_ratio) override;
+
+  // Called by MainSequence to update which texture this effect reads from
+  virtual void update_bind_group(WGPUTextureView input_view) = 0;
+
+protected:
+  WGPURenderPipeline pipeline_ = nullptr;
+  WGPUBindGroup bind_group_ = nullptr;
 };
 
 struct SequenceItem {
@@ -61,24 +81,17 @@ public:
   int priority = 0; // Render order of this sequence (higher = later/top)
 
   void init(MainSequence *demo);
-  
+
   // Add an effect to the sequence.
-  // start_time, end_time: Relative to sequence start.
-  // priority: Drawing order within this sequence.
   void add_effect(std::shared_ptr<Effect> effect, float start_time,
                   float end_time, int priority = 0);
 
   // Updates active state of effects based on sequence-local time.
-  // seq_time: Time relative to sequence start.
   void update_active_list(float seq_time);
 
-  // Calls compute() on all active effects (sorted by priority).
-  void dispatch_compute(WGPUCommandEncoder encoder, float seq_time, float beat,
-                        float intensity, float aspect_ratio);
-
-  // Calls render() on all active effects (sorted by priority).
-  void dispatch_render(WGPURenderPassEncoder pass, float seq_time, float beat,
-                       float intensity, float aspect_ratio);
+  // Gathers active effects into lists for processing.
+  void collect_active_effects(std::vector<SequenceItem *> &scene_effects,
+                              std::vector<SequenceItem *> &post_effects);
 
   void reset();
 
@@ -90,26 +103,30 @@ private:
 
 class MainSequence {
 public:
+  MainSequence();
+  ~MainSequence(); // Defined in .cc to handle unique_ptr to incomplete type
+
   WGPUDevice device;
   WGPUQueue queue;
   WGPUTextureFormat format;
 
-  void init(WGPUDevice device, WGPUQueue queue, WGPUTextureFormat format);
-  
+  void init(WGPUDevice device, WGPUQueue queue, WGPUTextureFormat format,
+            int width, int height);
+
   // Add a sequence to the demo.
-  // start_time: Global time when this sequence starts.
-  // priority: Layering order (higher = on top).
-  void add_sequence(std::shared_ptr<Sequence> seq, float start_time, int priority = 0);
+  void add_sequence(std::shared_ptr<Sequence> seq, float start_time,
+                    int priority = 0);
 
   // Renders the full frame: updates sequences, runs compute, runs render pass.
   void render_frame(float global_time, float beat, float peak,
                     float aspect_ratio, WGPUSurface surface);
 
+  void shutdown();
+
+#ifndef STRIP_ALL
   // Fast-forwards the simulation (updates & compute) without rendering.
-  // Used for seeking/debugging.
   void simulate_until(float target_time, float step_rate);
-
-  void shutdown();
+#endif
 
 private:
   struct ActiveSequence {
@@ -118,4 +135,15 @@ private:
     int priority;
   };
   std::vector<ActiveSequence> sequences_;
+
+  // Framebuffers for post-processing
+  WGPUTexture framebuffer_a_ = nullptr;
+  WGPUTextureView framebuffer_view_a_ = nullptr;
+  WGPUTexture framebuffer_b_ = nullptr;
+  WGPUTextureView framebuffer_view_b_ = nullptr;
+
+  // Default passthrough effect for blitting
+  std::unique_ptr<PostProcessEffect> passthrough_effect_;
+
+  void create_framebuffers(int width, int height);
 };