Method _parseStruct

src/webgpu/p5.RendererWebGPU.js:2135–2244

(shaderSource, structName)

    }

    _parseStruct(shaderSource, structName) {
      const structMatch = shaderSource.match(
        new RegExp(`struct\\s+${structName}\\s*\\{([^\\}]+)\\}`)
      );
      if (!structMatch) {
        throw new Error(`Can't find a struct definition for ${structName}`);
      }

      const structBody = structMatch[1];
      const elements = {};
      let match;
      let index = 0;
      let offset = 0;

      const elementRegex =
        /(?:@location\((\d+)\)\s+)?(\w+):\s*([^\n]+?),?\n/g

      const baseAlignAndSize = (type) => {
        if (['f32', 'i32', 'u32', 'bool'].includes(type)) {
          return { align: 4, size: 4, items: 1, baseType: type };
        }
        if (/^vec[2-4](<f32>|f)$/.test(type)) {
          const n = parseInt(type.match(/^vec([2-4])/)[1]);
          const size = 4 * n;
          const align = n === 2 ? 8 : 16;
          return { align, size, items: n, baseType: 'f32' };
        }
        if (/^vec[2-4]<(i32|u32)>$/.test(type)) {
          const n = parseInt(type.match(/^vec([2-4])/)[1]);
          const match = type.match(/^vec[2-4]<(i32|u32)>$/);
          const baseType = match[1]; // 'i32' or 'u32'
          const size = 4 * n;
          const align = n === 2 ? 8 : 16;
          return { align, size, items: n, baseType };
        }
        if (/^mat[2-4](?:x[2-4])?(<f32>|f)$/.test(type)) {
          if (type[4] === 'x' && type[3] !== type[5]) {
            throw new Error('Non-square matrices not implemented yet');
          }
          const dim = parseInt(type[3]);
          const align = dim === 2 ? 8 : 16;
          // Each column must be aligned
          const size = Math.ceil(dim * 4 / align) * align * dim;
          // For mat3, use in-place packing to avoid array allocation
          const pack = dim === 3
            ? (data) => [
              ...data.slice(0, 3),
              ...data.slice(3, 6),
              ...data.slice(6, 9),
            ]
            : undefined;
          const packInPlace = dim === 3;
          return { align, size, pack, packInPlace, items: dim * dim, baseType: 'f32' };
        }
        if (/^array<.+>$/.test(type)) {
          const [, subtype, rawLength] = type.match(/^array<(.+),\s*(\d+)>/);
          const length = parseInt(rawLength);
          const {