feat: Multi-pass rendering architecture and effect stubs

Implements a post-processing pipeline using offscreen framebuffers. Adds stubs for MovingEllipse, ParticleSpray, GaussianBlur, Solarize, Distort, and ChromaAberration effects. Updates MainSequence to orchestrate the scene pass and post-processing chain.

1 files changed, 88 insertions, 2 deletions

diff --git a/src/gpu/demo_effects.h b/src/gpu/demo_effects.h
index befb1fe..35ebe37 100644
--- a/src/gpu/demo_effects.h
+++ b/src/gpu/demo_effects.h
@@ -3,9 +3,18 @@
 
 #pragma once
 #include "effect.h"
-#include "gpu.h"
+#include "gpu/gpu.h"
 #include <memory>
 
+static const int NUM_PARTICLES = 10000;
+
+struct Particle {
+  float pos[4];
+  float vel[4];
+  float rot[4];
+  float color[4];
+};
+
 class HeptagonEffect : public Effect {
 public:
   HeptagonEffect(WGPUDevice device, WGPUQueue queue, WGPUTextureFormat format);
@@ -34,6 +43,83 @@ private:
   GpuBuffer uniforms_;
 };
 
+class PassthroughEffect : public PostProcessEffect {
+public:
+  PassthroughEffect(WGPUDevice device, WGPUTextureFormat format);
+  void update_bind_group(WGPUTextureView input_view) override;
+
+private:
+  WGPUDevice device_;
+};
+
+class MovingEllipseEffect : public Effect {
+public:
+  MovingEllipseEffect(WGPUDevice device, WGPUQueue queue,
+                      WGPUTextureFormat format);
+  void render(WGPURenderPassEncoder pass, float time, float beat,
+              float intensity, float aspect_ratio) override;
+
+private:
+  WGPUQueue queue_;
+  RenderPass pass_;
+  GpuBuffer uniforms_;
+};
+
+class ParticleSprayEffect : public Effect {
+public:
+  ParticleSprayEffect(WGPUDevice device, WGPUQueue queue,
+                      WGPUTextureFormat format);
+  void compute(WGPUCommandEncoder encoder, float time, float beat,
+               float intensity, float aspect_ratio) override;
+  void render(WGPURenderPassEncoder pass, float time, float beat,
+              float intensity, float aspect_ratio) override;
+
+private:
+  WGPUQueue queue_;
+  ComputePass compute_pass_;
+  RenderPass render_pass_;
+  GpuBuffer particles_buffer_;
+  GpuBuffer uniforms_;
+};
+
+class GaussianBlurEffect : public PostProcessEffect {
+public:
+  GaussianBlurEffect(WGPUDevice device, WGPUQueue queue,
+                     WGPUTextureFormat format);
+  void update_bind_group(WGPUTextureView input_view) override;
+
+private:
+  WGPUDevice device_;
+};
+
+class SolarizeEffect : public PostProcessEffect {
+public:
+  SolarizeEffect(WGPUDevice device, WGPUQueue queue, WGPUTextureFormat format);
+  void update_bind_group(WGPUTextureView input_view) override;
+
+private:
+  WGPUDevice device_;
+};
+
+class DistortEffect : public PostProcessEffect {
+public:
+  DistortEffect(WGPUDevice device, WGPUQueue queue, WGPUTextureFormat format);
+  void update_bind_group(WGPUTextureView input_view) override;
+
+private:
+  WGPUDevice device_;
+};
+
+class ChromaAberrationEffect : public PostProcessEffect {
+public:
+  ChromaAberrationEffect(WGPUDevice device, WGPUQueue queue,
+                         WGPUTextureFormat format);
+  void update_bind_group(WGPUTextureView input_view) override;
+
+private:
+  WGPUDevice device_;
+};
+
 // Auto-generated function to populate the timeline
 void LoadTimeline(MainSequence &main_seq, WGPUDevice device, WGPUQueue queue,
-                  WGPUTextureFormat format);
+                  WGPUTextureFormat format);
\ No newline at end of file