Method getUniformMetadata

src/webgpu/p5.RendererWebGPU.js:2261–2396

(shader)

    }

    getUniformMetadata(shader) {
      // Parse all uniform struct bindings in group 0.
      // TODO: support non-sampler uniforms being in other groups

      // Each binding represents a logical group of uniforms, since they get
      // updated or cached all at once.

      const uniformGroups = [];
      const uniformVarRegex = /@group\((\d+)\)\s+@binding\((\d+)\)\s+var<uniform>\s+(\w+)\s*:\s*(\w+);/g;

      let match;
      const src = shader.shaderType === 'compute' ? shader.computeSrc() : shader.vertSrc();
      while ((match = uniformVarRegex.exec(src)) !== null) {
        const [_, groupNum, binding, varName, structType] = match;
        const bindingIndex = parseInt(binding);
        const uniforms = this._parseStruct(src, structType);

        uniformGroups.push({
          group: parseInt(groupNum),
          binding: bindingIndex,
          varName,
          structType,
          uniforms
        });
      }

      if (uniformGroups.length === 0 && shader.shaderType !== 'compute') {
        throw new Error('Expected at least one uniform struct bound to @group(0)');
      }

      // While we're also keeping track of the groups, the API we expose
      // to users of p5 is just a flat list of uniforms (which can be the
      // individual struct items in the group.)
      const allUniforms = {};
      for (const group of uniformGroups) {
        for (const [uniformName, uniformData] of Object.entries(group.uniforms)) {
          allUniforms[uniformName] = {
            ...uniformData,
            group: group.group,
            binding: group.binding,
            varName: group.varName
          };
        }
      }

      // Store uniform groups for buffer pooling
      shader._uniformGroups = uniformGroups;

      // Extract samplers from group bindings
      const samplers = {};
      // TODO: support other texture types
      const samplerRegex = /@group\((\d+)\)\s*@binding\((\d+)\)\s*var\s+(\w+)\s*:\s*(texture_2d<f32>|sampler);/g;

      // Extract storage buffers
      const storageBuffers = {};
      const storageRegex = /@group\((\d+)\)\s*@binding\((\d+)\)\s*var<storage,\s*(read|read_write)>\s+(\w+)\s*:\s*array<\w+>/g;

      // Track which bindings are taken by the struct properties we've parsed