1 files changed, 47 insertions, 0 deletions
diff --git a/src/effects/particles_effect.cc b/src/effects/particles_effect.cc
new file mode 100644
index 0000000..5762637
--- /dev/null
+++ b/src/effects/particles_effect.cc
@@ -0,0 +1,47 @@
+// This file is part of the 64k demo project.
+// It implements the ParticlesEffect.
+
+#include "gpu/demo_effects.h"
+#include "gpu/post_process_helper.h"
+#include "gpu/gpu.h"
+#include <vector>
+
+// --- ParticlesEffect ---
+ParticlesEffect::ParticlesEffect(const GpuContext& ctx) : Effect(ctx) {
+  std::vector<Particle> init_p(NUM_PARTICLES);
+  particles_buffer_ = gpu_create_buffer(
+      ctx_.device, sizeof(Particle) * NUM_PARTICLES,
+      WGPUBufferUsage_Storage | WGPUBufferUsage_Vertex, init_p.data());
+  ResourceBinding cb[] = {{particles_buffer_, WGPUBufferBindingType_Storage},
+                          {uniforms_.get(), WGPUBufferBindingType_Uniform}};
+  compute_pass_ =
+      gpu_create_compute_pass(ctx_.device, particle_compute_wgsl, cb, 2);
+  compute_pass_.workgroup_size_x = (NUM_PARTICLES + 63) / 64;
+  ResourceBinding rb[] = {
+      {particles_buffer_, WGPUBufferBindingType_ReadOnlyStorage},
+      {uniforms_.get(), WGPUBufferBindingType_Uniform}};
+  render_pass_ = gpu_create_render_pass(ctx_.device, ctx_.format,
+                                        particle_render_wgsl, rb, 2);
+  render_pass_.vertex_count = 6;
+  render_pass_.instance_count = NUM_PARTICLES;
+}
+void ParticlesEffect::compute(WGPUCommandEncoder e,
+                              const CommonPostProcessUniforms& uniforms) {
+  uniforms_.update(ctx_.queue, uniforms);
+  WGPUComputePassEncoder pass = wgpuCommandEncoderBeginComputePass(e, nullptr);
+  wgpuComputePassEncoderSetPipeline(pass, compute_pass_.pipeline);
+  wgpuComputePassEncoderSetBindGroup(pass, 0, compute_pass_.bind_group, 0,
+                                     nullptr);
+  wgpuComputePassEncoderDispatchWorkgroups(pass, compute_pass_.workgroup_size_x,
+                                           1, 1);
+  wgpuComputePassEncoderEnd(pass);
+}
+void ParticlesEffect::render(WGPURenderPassEncoder pass,
+                             const CommonPostProcessUniforms& uniforms) {
+  (void)uniforms;
+  wgpuRenderPassEncoderSetPipeline(pass, render_pass_.pipeline);
+  wgpuRenderPassEncoderSetBindGroup(pass, 0, render_pass_.bind_group, 0,
+                                    nullptr);
+  wgpuRenderPassEncoderDraw(pass, render_pass_.vertex_count,
+                            render_pass_.instance_count, 0, 0);
+}