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, 8 insertions, 12 deletions

diff --git a/src/effects/passthrough_effect.cc b/src/effects/passthrough_effect.cc
index 02f14da..24eefca 100644
--- a/src/effects/passthrough_effect.cc
+++ b/src/effects/passthrough_effect.cc
@@ -9,15 +9,14 @@ Passthrough::Passthrough(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_linear_sampler();
 
-  pipeline_ = create_post_process_pipeline_simple(
-      ctx_.device, WGPUTextureFormat_RGBA8Unorm, passthrough_shader_wgsl);
+  pipeline_.set(create_post_process_pipeline_simple(
+      ctx_.device, WGPUTextureFormat_RGBA8Unorm, passthrough_shader_wgsl));
 }
 
 void Passthrough::render(WGPUCommandEncoder encoder,
@@ -33,7 +32,7 @@ void Passthrough::render(WGPUCommandEncoder encoder,
   // Manually create bind group with only 3 entries (no effect params needed)
   WGPUBindGroupEntry entries[3] = {};
   entries[0].binding = PP_BINDING_SAMPLER;
-  entries[0].sampler = sampler_;
+  entries[0].sampler = sampler_.get();
   entries[1].binding = PP_BINDING_TEXTURE;
   entries[1].textureView = input_view;
   entries[2].binding = PP_BINDING_UNIFORMS;
@@ -41,14 +40,11 @@ void Passthrough::render(WGPUCommandEncoder encoder,
   entries[2].size = sizeof(UniformsSequenceParams);
 
   WGPUBindGroupDescriptor bg_desc = {};
-  bg_desc.layout = wgpuRenderPipelineGetBindGroupLayout(pipeline_, 0);
+  bg_desc.layout = wgpuRenderPipelineGetBindGroupLayout(pipeline_.get(), 0);
   bg_desc.entryCount = 3;
   bg_desc.entries = entries;
 
-  if (bind_group_) {
-    wgpuBindGroupRelease(bind_group_);
-  }
-  bind_group_ = wgpuDeviceCreateBindGroup(ctx_.device, &bg_desc);
+  bind_group_.replace(wgpuDeviceCreateBindGroup(ctx_.device, &bg_desc));
 
   // Render pass
   WGPURenderPassColorAttachment color_attachment = {};
@@ -60,8 +56,8 @@ void Passthrough::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);