refactor(gpu): Add RAII wrapper for WGPU resources to eliminate manual cleanup

Introduces WGPUResource template with automatic release on destruction.
Reduces boilerplate in effect destructors and prevents resource leaks.

- set() for one-time initialization
- replace() for per-frame recreation
- Field ordering documented for dependency management

Converted 3 effects (Heptagon, Flash, Passthrough) and Effect base class.
All tests pass (34/34).

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

1 files changed, 7 insertions, 20 deletions

diff --git a/src/effects/heptagon_effect.cc b/src/effects/heptagon_effect.cc
index 46d6f7f..c9ec17c 100644
--- a/src/effects/heptagon_effect.cc
+++ b/src/effects/heptagon_effect.cc
@@ -10,28 +10,15 @@ Heptagon::Heptagon(const GpuContext& ctx,
                    const std::vector<std::string>& inputs,
                    const std::vector<std::string>& outputs, float start_time,
                            float end_time)
-    : Effect(ctx, inputs, outputs, start_time, end_time), pipeline_(nullptr), bind_group_(nullptr) {
+    : Effect(ctx, inputs, outputs, start_time, end_time) {
   HEADLESS_RETURN_IF_NULL(ctx_.device);
 
   init_uniforms_buffer();
   create_nearest_sampler();
   create_dummy_scene_texture();
 
-  pipeline_ = create_post_process_pipeline(
-      ctx_.device, WGPUTextureFormat_RGBA8Unorm, heptagon_shader_wgsl);
-}
-
-Heptagon::~Heptagon() {
-  if (bind_group_)
-    wgpuBindGroupRelease(bind_group_);
-  if (pipeline_)
-    wgpuRenderPipelineRelease(pipeline_);
-  if (sampler_)
-    wgpuSamplerRelease(sampler_);
-  if (dummy_texture_view_)
-    wgpuTextureViewRelease(dummy_texture_view_);
-  if (dummy_texture_)
-    wgpuTextureRelease(dummy_texture_);
+  pipeline_.set(create_post_process_pipeline(
+      ctx_.device, WGPUTextureFormat_RGBA8Unorm, heptagon_shader_wgsl));
 }
 
 void Heptagon::render(WGPUCommandEncoder encoder,
@@ -44,8 +31,8 @@ void Heptagon::render(WGPUCommandEncoder encoder,
   uniforms_buffer_.update(ctx_.queue, params);
 
   // Create bind group (use dummy texture for scene effect)
-  pp_update_bind_group(ctx_.device, pipeline_, &bind_group_,
-                       dummy_texture_view_, uniforms_buffer_.get(),
+  pp_update_bind_group(ctx_.device, pipeline_.get(), bind_group_.get_address(),
+                       dummy_texture_view_.get(), uniforms_buffer_.get(),
                        {nullptr, 0});
 
   // Render pass
@@ -58,8 +45,8 @@ void Heptagon::render(WGPUCommandEncoder encoder,
 
   WGPURenderPassEncoder pass =
       wgpuCommandEncoderBeginRenderPass(encoder, &pass_desc);
-  wgpuRenderPassEncoderSetPipeline(pass, pipeline_);
-  wgpuRenderPassEncoderSetBindGroup(pass, 0, bind_group_, 0, nullptr);
+  wgpuRenderPassEncoderSetPipeline(pass, pipeline_.get());
+  wgpuRenderPassEncoderSetBindGroup(pass, 0, bind_group_.get(), 0, nullptr);
   wgpuRenderPassEncoderDraw(pass, 3, 1, 0, 0); // Fullscreen triangle
   wgpuRenderPassEncoderEnd(pass);
   wgpuRenderPassEncoderRelease(pass);