typegpu/data/disarray.js

A thin layer between JS and WebGPU/WGSL that improves development experience and allows for faster iteration.

import { comptime } from "../core/function/comptime.js";
import { $internal } from "../shared/symbols.js";
import { schemaCallWrapper } from "./schemaCallWrapper.js";
/**
 * Creates an array schema that can be used to construct vertex buffers.
 * Describes arrays with fixed-size length, storing elements of the same type.
 *
 * Elements in the schema are not aligned in respect to their `byteAlignment`,
 * unless they are explicitly decorated with the custom align attribute
 * via `d.align` function.
 *
 * @example
 * const disarray = d.disarrayOf(d.vec3f, 3); // packed array of vec3f
 *
 * @example
 * const disarray = d.disarrayOf(d.align(16, d.vec3f), 3);
 *
 * If `elementCount` is not specified, a partially applied function is returned.
 * @example
 * const disarray = d.disarrayOf(d.vec3f);
 * //    ^? (n: number) => Disarray<d.Vec3f>
 *
 * @param elementType The type of elements in the array.
 * @param elementCount The number of elements in the array.
 */
export const disarrayOf = comptime(((elementType, elementCount) => {
    if (elementCount === undefined) {
        return (count) => cpu_disarrayOf(elementType, count);
    }
    return cpu_disarrayOf(elementType, elementCount);
})).$name('disarrayOf');
export function cpu_disarrayOf(elementType, elementCount) {
    // In the schema call, create and return a deep copy
    // by wrapping all the values in `elementType` schema calls.
    const disarraySchema = (elements) => {
        if (elements && elements.length !== elementCount) {
            throw new Error(`Disarray schema of ${elementCount} elements of type ${elementType.type} called with ${elements.length} argument(s).`);
        }
        return Array.from({ length: elementCount }, (_, i) => schemaCallWrapper(elementType, elements?.[i]));
    };
    Object.setPrototypeOf(disarraySchema, DisarrayImpl);
    disarraySchema.elementType = elementType;
    if (!Number.isInteger(elementCount) || elementCount < 0) {
        throw new Error(`Cannot create disarray schema with invalid element count: ${elementCount}.`);
    }
    disarraySchema.elementCount = elementCount;
    return disarraySchema;
}
// --------------
// Implementation
// --------------
const DisarrayImpl = {
    [$internal]: true,
    type: 'disarray',
    toString() {
        return `disarrayOf(${this.elementType}, ${this.elementCount})`;
    },
};