feat: Implement 3D system and procedural texture manager

- Extended mini_math.h with mat4 multiplication and affine transforms.
- Implemented TextureManager for runtime procedural texture generation and GPU upload.
- Added 3D system components: Camera, Object, Scene, and Renderer3D.
- Created test_3d_render mini-demo for interactive 3D verification.
- Fixed WebGPU validation errors regarding depthSlice and unimplemented WaitAny.

1 files changed, 48 insertions, 0 deletions

diff --git a/src/gpu/texture_manager.h b/src/gpu/texture_manager.h
new file mode 100644
index 0000000..3faf74c
--- /dev/null
+++ b/src/gpu/texture_manager.h
@@ -0,0 +1,48 @@
+// This file is part of the 64k demo project.
+// It defines the TextureManager for procedural assets.
+// Handles generation and GPU upload of procedural textures.
+
+#pragma once
+
+#include "gpu/gpu.h"
+#include <map>
+#include <string>
+#include <vector>
+
+#if defined(DEMO_CROSS_COMPILE_WIN32)
+#include <webgpu/webgpu.h>
+#else
+#include <webgpu.h>
+#endif
+
+struct ProceduralTextureDef {
+  int width;
+  int height;
+  void (*gen_func)(uint8_t*, int, int, const float*, int);
+  std::vector<float> params;
+};
+
+struct GpuTexture {
+  WGPUTexture texture;
+  WGPUTextureView view;
+  int width;
+  int height;
+};
+
+class TextureManager {
+ public:
+  void init(WGPUDevice device, WGPUQueue queue);
+  void shutdown();
+
+  // Registers and generates a texture immediately
+  void create_procedural_texture(const std::string& name,
+                                 const ProceduralTextureDef& def);
+
+  // Retrieves a texture view by name (returns nullptr if not found)
+  WGPUTextureView get_texture_view(const std::string& name);
+
+ private:
+  WGPUDevice device_;
+  WGPUQueue queue_;
+  std::map<std::string, GpuTexture> textures_;
+};