c-structs/dist/index.mjs

// src/index.ts
var p = {
  float32: {
    size: 4,
    arrayType: Float32Array,
    getter: "getFloat32",
    setter: "setFloat32"
  },
  float64: {
    size: 8,
    arrayType: Float64Array,
    getter: "getFloat64",
    setter: "setFloat64"
  },
  uint16: {
    size: 2,
    arrayType: Uint16Array,
    getter: "getUint16",
    setter: "setUint16"
  },
  uint32: {
    size: 4,
    arrayType: Uint32Array,
    getter: "getUint32",
    setter: "setUint32"
  },
  uint64: {
    size: 8,
    arrayType: BigUint64Array,
    getter: "getBigUint64",
    setter: "setBigUint64"
  },
  int16: {
    size: 2,
    arrayType: Int16Array,
    getter: "getInt16",
    setter: "setInt16"
  },
  int32: {
    size: 4,
    arrayType: Int32Array,
    getter: "getInt32",
    setter: "setInt32"
  },
  int64: {
    size: 8,
    arrayType: BigInt64Array,
    getter: "getBigInt64",
    setter: "setBigInt64"
  }
};
var c = {
  // Vector of floats
  float() {
    return p.float32;
  },
  float2() {
    return [p.float32, p.float32];
  },
  float3() {
    return [p.float32, p.float32, p.float32];
  },
  float4() {
    return [p.float32, p.float32, p.float32, p.float32];
  },
  uint() {
    return p.uint32;
  },
  uint2() {
    return [p.uint32, p.uint32];
  },
  uint3() {
    return [p.uint32, p.uint32, p.uint32];
  },
  uint4() {
    return [p.uint32, p.uint32, p.uint32, p.uint32];
  },
  matrix4() {
    return [
      p.float32,
      p.float32,
      p.float32,
      p.float32,
      p.float32,
      p.float32,
      p.float32,
      p.float32,
      p.float32,
      p.float32,
      p.float32,
      p.float32,
      p.float32,
      p.float32,
      p.float32,
      p.float32
    ];
  },
  /**
   * Create an array descriptor for nested structs.
   */
  array(structDesc, length) {
    if (typeof structDesc.size !== "number" || typeof structDesc.create !== "function") {
      throw new Error("c.array: first arg must be a StructDescriptor");
    }
    if (!Number.isInteger(length) || length <= 0) {
      throw new Error("c.array: length must be a positive integer");
    }
    return {
      size: structDesc.size * length,
      create(buffer = new ArrayBuffer(structDesc.size * length), baseOffset = 0) {
        const arr = [];
        for (let i = 0; i < length; i++) {
          arr.push(structDesc.create(buffer, baseOffset + i * structDesc.size));
        }
        Object.defineProperty(arr, "buffer", {
          get: () => buffer,
          enumerable: false
        });
        return arr;
      }
    };
  },
  /**
   * Create a struct descriptor from a schema map.
   */
  struct(schema) {
    let offset = 0;
    const fields = [];
    for (const [name, type] of Object.entries(schema)) {
      const fieldOffset = offset;
      let entry;
      if (Array.isArray(type)) {
        const elem = type[0];
        entry = {
          kind: "vector",
          name,
          elem,
          length: type.length,
          offset: fieldOffset
        };
        offset += elem.size * type.length;
      } else if (type.size && typeof type.create === "function" && Array.isArray(type.create())) {
        entry = {
          kind: "array",
          name,
          elemDesc: type,
          length: type.length,
          offset: fieldOffset
        };
        offset += type.size * type.length;
      } else if (type.arrayType) {
        const elem = type;
        entry = {
          kind: "scalar",
          name,
          desc: elem,
          offset: fieldOffset
        };
        offset += elem.size;
      } else if (type.size && typeof type.create === "function") {
        entry = {
          kind: "struct",
          name,
          desc: type,
          offset: fieldOffset
        };
        offset += type.size;
      } else {
        throw new Error(`Unknown field type for "${name}"`);
      }
      fields.push(entry);
    }
    const totalSize = offset;
    return {
      size: totalSize,
      create(buffer = new ArrayBuffer(totalSize), baseOffset = 0) {
        const view = new DataView(buffer);
        const inst = {};
        for (const f of fields) {
          const abs = baseOffset + f.offset;
          switch (f.kind) {
            case "scalar":
              Object.defineProperty(inst, f.name, {
                get: () => view[f.desc.getter](abs, true),
                set: (v) => view[f.desc.setter](abs, v, true),
                enumerable: true
              });
              break;
            case "vector": {
              const Typed = f.elem.arrayType;
              const ta = new Typed(buffer, abs, f.length);
              Object.defineProperty(inst, f.name, {
                get: () => ta,
                set: (arr) => {
                  for (let i = 0; i < f.length; i++) ta[i] = arr[i];
                },
                enumerable: true
              });
              break;
            }
            case "struct":
              inst[f.name] = f.desc.create(buffer, abs);
              break;
            case "array":
              inst[f.name] = c.array(f.elemDesc, f.length).create(buffer, abs);
              break;
          }
        }
        Object.defineProperty(inst, "buffer", {
          get: () => buffer,
          enumerable: false
        });
        return inst;
      }
    };
  }
};
export {
  c,
  p
};