diff --git a/WEBGPU_MIGRATION.md b/WEBGPU_MIGRATION.md new file mode 100644 index 0000000..099b4bb --- /dev/null +++ b/WEBGPU_MIGRATION.md @@ -0,0 +1,164 @@ +# WebGPU Migration Complete + +## Overview +Successfully migrated the WebOcean project from WebGL2 to WebGPU to enable future tessellation support for the ocean grid system. + +## What Changed + +### Files Converted to WebGPU: + +1. **Grid.ts** + - Replaced WebGL VAO/VBO with GPUBuffer + - Updated `initVAO()` → `initBuffers(gpuContext: WebGPUContext)` + - Changed `draw(gl: WebGL2RenderingContext)` → `draw(renderPass: GPURenderPassEncoder)` + - Uses `mappedAtCreation` pattern for buffer initialization + +2. **Skybox.ts** + - Same conversion pattern as Grid + - Replaced WebGL buffers with GPUBuffer + - Updated draw method signature for WebGPU + +3. **main.ts** (renamed from main_webgpu.ts) + - Replaced `initGL()` with async `initWebGPU()` + - Created three render pipelines: + * Noise generation pipeline (renders Perlin noise to texture) + * Ocean rendering pipeline (vertex displacement from noise texture) + * Skybox pipeline (gradient sky with sun) + - Converted FBO to GPUTexture for render-to-texture + - Updated all shader bindings to use WebGPU bind groups + - Maintains all existing features: + * Dual camera system (Orbital + FPS) + * Animation controls (P pause, 0-5 speed) + * Wireframe toggle (F key) + * Camera switching (C key) + * Full WASD + mouse controls + +### New Files Created: + +1. **WebGPUContext.ts** + - Centralized GPU device/adapter/context management + - Provides helper methods for creating buffers, textures, pipelines + - Handles WebGPU initialization and configuration + +2. **shaders.wgsl.ts** + - All GLSL shaders converted to WGSL format + - Exports 6 shader strings: + * `noiseVertexShader` - fullscreen quad for noise generation + * `noiseFragmentShader` - 5-octave Perlin noise + * `oceanVertexShader` - vertex displacement from texture + * `oceanFragmentShader` - normal calculation, Fresnel, SSS, glitter + * `skyboxVertexShader` - skybox cube rendering + * `skyboxFragmentShader` - gradient sky with sun + +### Preserved Files: + +1. **main_webgl.ts** (backup) + - Original WebGL2 implementation preserved for reference + - Excluded from TypeScript compilation + +### Configuration Updates: + +1. **tsconfig.json** + - Added `"types": ["@webgpu/types"]` for WebGPU type definitions + - Excluded `main_webgl.ts` from compilation + +2. **package.json** + - Added `@webgpu/types` dev dependency + +3. **index.html** + - Added frame time display (`
`) + - Kept GLSL shader script tags (not used, can be removed later) + +## WebGPU vs WebGL2 Architecture + +### Key Differences: + +| Aspect | WebGL2 | WebGPU | +|--------|--------|--------| +| **Buffers** | VAO/VBO with gl.createVertexArray() | GPUBuffer with device.createBuffer() | +| **Shaders** | GLSL with gl.createProgram() | WGSL with device.createShaderModule() | +| **Rendering** | Direct gl.drawArrays() calls | Command encoder → render pass → submit | +| **Textures** | gl.createTexture() + gl.texImage2D() | device.createTexture() | +| **State** | Implicit state machine (gl.enable/disable) | Explicit pipeline state in descriptors | +| **Uniforms** | gl.uniformMatrix4fv() per draw | Uniform buffers + bind groups | + +### Rendering Pipeline: + +**Pass 1: Noise Generation** +``` +1. Write time uniform to buffer +2. Create command encoder +3. Begin render pass with noiseTexture as target +4. Set noise pipeline +5. Set noise bind group (contains time uniform) +6. Draw fullscreen quad (6 vertices) +7. End pass and submit commands +``` + +**Pass 2: Scene Rendering** +``` +1. Update camera uniforms (view, model, projection, eyePos) +2. Update skybox uniforms (view, projection, sunDir) +3. Create command encoder +4. Begin render pass with canvas + depth texture +5. Draw skybox: + - Set skybox pipeline (no depth write, no culling) + - Set skybox bind group + - Draw skybox geometry +6. Draw ocean: + - Set ocean pipeline (depth write, back-face culling) + - Set ocean bind group (contains uniforms + noise texture + sampler) + - Draw ocean grid (wireframe or solid) +7. End pass and submit commands +``` + +## Browser Compatibility + +- **Requires**: Chrome/Edge 113+, Firefox 130+ (with flag) +- **Not supported**: Safari (as of December 2024) +- Shows error alert if WebGPU not available + +## Testing Checklist + +✅ Build succeeds without TypeScript errors +✅ Dev server starts successfully +✅ WebGPU initialization completes +✅ Dual camera system functional +✅ Animation controls work (pause/play/speed) +✅ Wireframe toggle functional +✅ Mouse camera controls responsive +✅ Keyboard FPS camera controls work + +## Next Steps - Tessellation + +Now that WebGPU migration is complete, tessellation can be implemented: + +1. **Hull Shader** - Define tessellation factors based on camera distance +2. **Domain Shader** - Interpolate tessellated vertices +3. **Dynamic LOD** - Increase subdivision near camera, reduce far away +4. **Adaptive Tessellation** - More detail in areas with high wave displacement + +This will provide: +- Smoother ocean surface at all zoom levels +- Better performance (fewer vertices far from camera) +- More geometric detail for displacement mapping +- Hardware-accelerated mesh subdivision + +## Files Modified Summary + +- ✅ [Grid.ts](Grid.ts) - WebGPU buffer conversion +- ✅ [Skybox.ts](Skybox.ts) - WebGPU buffer conversion +- ✅ [main.ts](main.ts) - Complete WebGPU rendering pipeline +- ✅ [WebGPUContext.ts](WebGPUContext.ts) - New GPU management class +- ✅ [shaders.wgsl.ts](shaders.wgsl.ts) - New WGSL shader definitions +- ✅ [tsconfig.json](../tsconfig.json) - Added WebGPU types +- ✅ [index.html](../index.html) - Added frame time display +- 📦 main_webgl.ts - Backup (excluded from build) + +## Performance Notes + +- FPS display shows frame rate +- Frame time display shows milliseconds per frame +- Animation speed control (1x-5x) +- Pause/play functionality preserved +- WebGPU generally faster than WebGL2 for complex scenes diff --git a/index.html b/index.html index 2e9be65..829fbd0 100644 --- a/index.html +++ b/index.html @@ -96,6 +96,19 @@ font-size: 14px; backdrop-filter: blur(10px); } + + #frame-time { + position: absolute; + bottom: 20px; + left: 100px; + background: rgba(0, 0, 0, 0.7); + color: #0ff; + padding: 8px 12px; + border-radius: 5px; + font-family: 'Courier New', monospace; + font-size: 14px; + backdrop-filter: blur(10px); + }