3 files changed, 20 insertions, 11 deletions
diff --git a/src/gpu/effects/flash_effect.cc b/src/gpu/effects/flash_effect.cc
index 217a7bb..5aebe2d 100644
--- a/src/gpu/effects/flash_effect.cc
+++ b/src/gpu/effects/flash_effect.cc
@@ -15,7 +15,7 @@ FlashEffect::FlashEffect(const GpuContext& ctx)
 
     struct Uniforms {
       flash_intensity: f32,
-      _pad0: f32,
+      intensity: f32,
       _pad1: f32,
       _pad2: f32,
     };
@@ -42,7 +42,9 @@ FlashEffect::FlashEffect(const GpuContext& ctx)
       let color = textureSample(inputTexture, inputSampler, input.uv);
       // Add white flash: blend towards white based on flash intensity
       let white = vec3<f32>(1.0, 1.0, 1.0);
-      let flashed = mix(color.rgb, white, uniforms.flash_intensity);
+      let green = vec3<f32>(0.0, 1.0, 0.0);
+      var flashed = mix(color.rgb, green, uniforms.intensity);
+      if (input.uv.y > .5) { flashed = mix(color.rgb, white, uniforms.flash_intensity); }
       return vec4<f32>(flashed, color.a);
     }
   )";
@@ -68,9 +70,9 @@ void FlashEffect::render(WGPURenderPassEncoder pass, float time, float beat,
   }
 
   // Exponential decay
-  flash_intensity_ *= 0.85f;
+  flash_intensity_ *= 0.98f;
 
-  float uniforms[4] = {flash_intensity_, 0.0f, 0.0f, 0.0f};
+  float uniforms[4] = {flash_intensity_, intensity, 0.0f, 0.0f};
   wgpuQueueWriteBuffer(ctx_.queue, uniforms_.buffer, 0, uniforms, sizeof(uniforms));
 
   wgpuRenderPassEncoderSetPipeline(pass, pipeline_);
diff --git a/src/gpu/effects/post_process_helper.cc b/src/gpu/effects/post_process_helper.cc
index db89d77..0a2ac22 100644
--- a/src/gpu/effects/post_process_helper.cc
+++ b/src/gpu/effects/post_process_helper.cc
@@ -1,6 +1,7 @@
 // This file is part of the 64k demo project.
 // It implements helper functions for post-processing effects.
 
+#include "post_process_helper.h"
 #include "../demo_effects.h"
 #include "gpu/gpu.h"
 #include <cstring>
@@ -18,15 +19,15 @@ WGPURenderPipeline create_post_process_pipeline(WGPUDevice device,
       wgpuDeviceCreateShaderModule(device, &shader_desc);
 
   WGPUBindGroupLayoutEntry bgl_entries[3] = {};
-  bgl_entries[0].binding = 0;
+  bgl_entries[0].binding = PP_BINDING_SAMPLER;
   bgl_entries[0].visibility = WGPUShaderStage_Fragment;
   bgl_entries[0].sampler.type = WGPUSamplerBindingType_Filtering;
-  bgl_entries[1].binding = 1;
+  bgl_entries[1].binding = PP_BINDING_TEXTURE;
   bgl_entries[1].visibility = WGPUShaderStage_Fragment;
   bgl_entries[1].texture.sampleType = WGPUTextureSampleType_Float;
   bgl_entries[1].texture.viewDimension = WGPUTextureViewDimension_2D;
-  bgl_entries[2].binding = 2;
-  bgl_entries[2].visibility = WGPUShaderStage_Fragment;
+  bgl_entries[2].binding = PP_BINDING_UNIFORMS;
+  bgl_entries[2].visibility = WGPUShaderStage_Vertex | WGPUShaderStage_Fragment;
   bgl_entries[2].buffer.type = WGPUBufferBindingType_Uniform;
 
   WGPUBindGroupLayoutDescriptor bgl_desc = {};
@@ -74,11 +75,11 @@ void pp_update_bind_group(WGPUDevice device, WGPURenderPipeline pipeline,
   sd.maxAnisotropy = 1;
   WGPUSampler sampler = wgpuDeviceCreateSampler(device, &sd);
   WGPUBindGroupEntry bge[3] = {};
-  bge[0].binding = 0;
+  bge[0].binding = PP_BINDING_SAMPLER;
   bge[0].sampler = sampler;
-  bge[1].binding = 1;
+  bge[1].binding = PP_BINDING_TEXTURE;
   bge[1].textureView = input_view;
-  bge[2].binding = 2;
+  bge[2].binding = PP_BINDING_UNIFORMS;
   bge[2].buffer = uniforms.buffer;
   bge[2].size = uniforms.size;
   WGPUBindGroupDescriptor bgd = {
diff --git a/src/gpu/effects/post_process_helper.h b/src/gpu/effects/post_process_helper.h
index 1986ff3..45757cf 100644
--- a/src/gpu/effects/post_process_helper.h
+++ b/src/gpu/effects/post_process_helper.h
@@ -5,7 +5,13 @@
 
 #include "gpu/gpu.h"
 
+// Standard post-process bind group layout (group 0):
+#define PP_BINDING_SAMPLER 0   // Sampler for input texture
+#define PP_BINDING_TEXTURE 1   // Input texture (previous render pass)
+#define PP_BINDING_UNIFORMS 2  // Custom uniforms buffer
+
 // Helper to create a standard post-processing pipeline
+// Uniforms are accessible to both vertex and fragment shaders
 WGPURenderPipeline create_post_process_pipeline(WGPUDevice device,
                                                 WGPUTextureFormat format,
                                                 const char* shader_code);