typegpu/core/declare/tgpuDeclare.js

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

import { snip } from "../../data/snippet.js";
import { Void } from "../../data/wgslTypes.js";
import { $internal, $resolve } from "../../shared/symbols.js";
import { replaceExternalsInWgsl } from "../resolve/externals.js";
/**
 * Allows defining extra declarations that shall be included in the final WGSL code,
 * when resolving objects that use them.
 *
 * Using this API is generally discouraged, as it shouldn't be necessary in any common scenario.
 * It was developed to ensure full compatibility of TypeGPU programs with current and future versions of WGSL.
 */
export function declare(declaration) {
    return new TgpuDeclareImpl(declaration);
}
// --------------
// Implementation
// --------------
class TgpuDeclareImpl {
    [$internal] = true;
    #externals;
    #declaration;
    constructor(declaration) {
        this.#declaration = declaration;
    }
    $uses(dependencyMap) {
        if (this.#externals !== undefined) {
            throw new Error("Cannot call '$uses' multiple times. If you wish to override dependencies, use slots or accessors instead.");
        }
        this.#externals = dependencyMap;
        return this;
    }
    [$resolve](ctx) {
        const replacedDeclaration = replaceExternalsInWgsl(ctx, this.#externals ?? {}, this.#declaration);
        ctx.addDeclaration(replacedDeclaration);
        return snip('', Void, /* origin */ 'constant');
    }
    toString() {
        return `declare: ${this.#declaration}`;
    }
}