scaffold-shader

Scaffold a simple WGSL shader

Generate a minimal, correct WGSL file (plus optional JS wiring) for a mesh rendered through RenderPipeline + Mesh. The base shader is deliberately bare — vs/fs with the standard transform uniforms and a fragment that outputs the normal mapped to 0..1. No custom uniforms, no textures: those are modifications you layer on top after generating, per the task. The reference shape is examples/hellowebgpu/cube.wgsl (same conventions).

Conventions that are NOT optional (reflection-enforced)

These come from webgpu-utils reflection in RenderPipeline/Mesh — get one wrong and the pipeline silently shades garbage or fails construction:

• Uniform block MUST be @group(0) @binding(0) var<uniform> uniforms : Uniforms. Lowercase uniforms, struct typed (commonly Uniforms). RenderPipeline reads this.defs.uniforms.uniforms by that exact name.
• Vertex entry point MUST be vs, fragment MUST be fs. Hardcoded.
• Mesh.draw writes standard uniforms BY NAME into the struct — only the fields that exist are written. Available: projectionMatrix, viewMatrix, modelViewMatrix, modelMatrix, objectMatrix (inverse model), normalMatrix (mat3x3f), cameraPosition (vec3f), cameraQuaternion (vec4f), resolution (vec2f), time (f32). Declare only the subset the shader uses, spelled exactly. Custom uniforms (e.g. uScale, uAlpha) go after them and are set via mesh.uniforms.set({...}) — the Mesh owns the uniform buffer, not the pipeline.
• Vertex attribute @location is assigned by declaration ORDER in the geometry's data object, not by name. Standard primitives (@core/primitives Box/Sphere/…) emit position (loc 0), normal (loc 1), uv (loc 2). The Vertex struct must match that order.
• Texture uniforms are named t<Name> (e.g. tMap). Samplers keep descriptive names. Only add these if the shader actually samples a texture — a declared binding with no bind-group entry throws at pipeline creation.