1 files changed, 58 insertions, 0 deletions
diff --git a/src/gpu/post_process_helper.cc b/src/gpu/post_process_helper.cc
new file mode 100644
index 0000000..4ffa9c1
--- /dev/null
+++ b/src/gpu/post_process_helper.cc
@@ -0,0 +1,58 @@
+// 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 "gpu/shader_composer.h"
+#include "gpu/bind_group_builder.h"
+#include "gpu/sampler_cache.h"
+#include "gpu/pipeline_builder.h"
+#include <cstring>
+
+// Helper to create a standard post-processing pipeline
+WGPURenderPipeline create_post_process_pipeline(WGPUDevice device,
+                                                WGPUTextureFormat format,
+                                                const char* shader_code) {
+  WGPUBindGroupLayout bgl = BindGroupLayoutBuilder()
+    .sampler(PP_BINDING_SAMPLER, WGPUShaderStage_Fragment)
+    .texture(PP_BINDING_TEXTURE, WGPUShaderStage_Fragment)
+    .uniform(PP_BINDING_UNIFORMS, WGPUShaderStage_Vertex | WGPUShaderStage_Fragment)
+    .uniform(PP_BINDING_EFFECT_PARAMS, WGPUShaderStage_Fragment)
+    .build(device);
+
+  WGPURenderPipeline pipeline = RenderPipelineBuilder(device)
+    .shader(shader_code)
+    .bind_group_layout(bgl)
+    .format(format)
+    .build();
+
+  wgpuBindGroupLayoutRelease(bgl);
+  return pipeline;
+}
+
+// --- PostProcess Implementation Helper ---
+static GpuBuffer g_dummy_buffer = {nullptr, 0};
+
+void pp_update_bind_group(WGPUDevice device, WGPURenderPipeline pipeline,
+                          WGPUBindGroup* bind_group, WGPUTextureView input_view,
+                          GpuBuffer uniforms, GpuBuffer effect_params) {
+  if (!g_dummy_buffer.buffer) {
+    g_dummy_buffer = gpu_create_buffer(device, 32, WGPUBufferUsage_Uniform);
+  }
+
+  if (*bind_group)
+    wgpuBindGroupRelease(*bind_group);
+
+  WGPUBindGroupLayout bgl = wgpuRenderPipelineGetBindGroupLayout(pipeline, 0);
+  WGPUSampler sampler = SamplerCache::Get().get_or_create(device, SamplerCache::linear());
+
+  *bind_group = BindGroupBuilder()
+    .sampler(PP_BINDING_SAMPLER, sampler)
+    .texture(PP_BINDING_TEXTURE, input_view)
+    .buffer(PP_BINDING_UNIFORMS, uniforms.buffer, uniforms.size)
+    .buffer(PP_BINDING_EFFECT_PARAMS,
+            effect_params.buffer ? effect_params.buffer : g_dummy_buffer.buffer,
+            effect_params.buffer ? effect_params.size : g_dummy_buffer.size)
+    .build(device, bgl);
+}