Refactor: Split demo effects and shaders into individual files

Split src/gpu/demo_effects.cc into individual .cc files for each effect
and created separate files for post-processing helpers and WGSL shaders.
Updated src/gpu/demo_effects.h to be a central header for all effect-related
declarations and adjusted CMakeLists.txt accordingly.

1 files changed, 28 insertions, 0 deletions

diff --git a/src/gpu/effects/moving_ellipse_effect.cc b/src/gpu/effects/moving_ellipse_effect.cc
new file mode 100644
index 0000000..60fc825
--- /dev/null
+++ b/src/gpu/effects/moving_ellipse_effect.cc
@@ -0,0 +1,28 @@
+// This file is part of the 64k demo project.
+// It implements the MovingEllipseEffect.
+
+#include "gpu/demo_effects.h"
+#include "gpu/gpu.h"
+
+// --- MovingEllipseEffect ---
+MovingEllipseEffect::MovingEllipseEffect(WGPUDevice device, WGPUQueue queue,
+                                         WGPUTextureFormat format)
+    : queue_(queue) {
+  uniforms_ =
+      gpu_create_buffer(device, sizeof(float) * 4,
+                        WGPUBufferUsage_Uniform | WGPUBufferUsage_CopyDst);
+  ResourceBinding bindings[] = {{uniforms_, WGPUBufferBindingType_Uniform}};
+  pass_ =
+      gpu_create_render_pass(device, format, ellipse_shader_wgsl, bindings, 1);
+  pass_.vertex_count = 3;
+}
+void MovingEllipseEffect::render(WGPURenderPassEncoder pass, float t, float b,
+                                 float i, float a) {
+  struct {
+    float t, b, i, a;
+  } u = {t, b, i, a};
+  wgpuQueueWriteBuffer(queue_, uniforms_.buffer, 0, &u, sizeof(u));
+  wgpuRenderPassEncoderSetPipeline(pass, pass_.pipeline);
+  wgpuRenderPassEncoderSetBindGroup(pass, 0, pass_.bind_group, 0, nullptr);
+  wgpuRenderPassEncoderDraw(pass, 3, 1, 0, 0);
+}