typegpu/data/snippet.js

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

import { undecorate } from "./dataTypes.js";
import { DEV } from "../shared/env.js";
import { isNumericSchema } from "./wgslTypes.js";
/**
 * What happens to a snippet's origin when it's deep copied in JS, and left as is in WGSL?
 * e.g. `vec3f(vec3f(0, 1, 2))`
 */
export function fallthroughCopyOrigin(origin) {
    if (origin === 'runtime' || // runtime values stay runtime
        origin === 'constant' // constant values stay constant
    ) {
        // The origin is kept as-is
        return origin;
    }
    // All other origins become runtime
    return 'runtime';
}
/**
 * Whether a snippet aliases a value that lives outside the current expression.
 *
 * @example
 * ```ts
 * function foo(a: number) {
 *   const color = d.vec3f(1, 2, 3);
 *   return color * a;
 * }
 *
 * // References:
 * // -  color
 * // -  a
 * //
 * // Not references:
 * // - d.vec3f(1, 2, 3)
 * // - color * a
 * ```
 */
export function isAlias(snippet) {
    return !(snippet.origin === 'runtime' || snippet.origin === 'constant');
}
export const originToPtrParams = {
    uniform: { space: 'uniform', access: 'read' },
    readonly: { space: 'storage', access: 'read' },
    mutable: { space: 'storage', access: 'read-write' },
    workgroup: { space: 'workgroup', access: 'read-write' },
    private: { space: 'private', access: 'read-write' },
    function: { space: 'function', access: 'read-write' },
    // Local declarations are also in the `function` address space
    'local-def': { space: 'function', access: 'read-write' },
};
class SnippetImpl {
    value;
    dataType;
    origin;
    possibleSideEffects;
    constructor(value, dataType, origin, possibleSideEffects) {
        this.value = value;
        this.dataType = dataType;
        this.origin = origin;
        this.possibleSideEffects = possibleSideEffects;
    }
}
export function isSnippet(value) {
    return value instanceof SnippetImpl;
}
export function isSnippetNumeric(snippet) {
    return isNumericSchema(snippet.dataType);
}
export function snip(value, dataType, origin, possibleSideEffects = true) {
    if (DEV && isSnippet(value)) {
        // An early error, but not worth checking every time in production
        throw new Error('Cannot nest snippets');
    }
    return new SnippetImpl(value, 
    // We don't care about attributes in snippet land, so we discard that information.
    undecorate(dataType), origin, possibleSideEffects);
}
export function withDataType(dataType, snippet) {
    return new SnippetImpl(snippet.value, dataType, snippet.origin, snippet.possibleSideEffects);
}
export function withValue(value, snippet) {
    return new SnippetImpl(value, snippet.dataType, snippet.origin, snippet.possibleSideEffects);
}
export function withSideEffects(possibleSideEffects, snippet) {
    return new SnippetImpl(snippet.value, snippet.dataType, snippet.origin, possibleSideEffects);
}
export function noSideEffects(snippet) {
    return withSideEffects(/* possibleSideEffects */ false, snippet);
}