thi-ng/umbrella

import type { UIntArray } from "@thi.ng/api";
import type {
    ITexture,
    ReadableTextureFormat,
    TextureType,
} from "./api/texture.js";
import { FBO } from "./fbo.js";

export const readPixels = <T extends UIntArray | Float32Array>(
    gl: WebGLRenderingContext,
    x: number,
    y: number,
    w: number,
    h: number,
    format: ReadableTextureFormat,
    type: TextureType,
    out: T
) => {
    gl.readPixels(x, y, w, h, format, type, out);
    return out;
};

export const readTexture = <
    T extends Uint8Array | Uint16Array | Uint32Array | Float32Array
>(
    gl: WebGLRenderingContext,
    tex: ITexture,
    format: ReadableTextureFormat,
    type: TextureType,
    out: T
) => {
    const fbo = new FBO(gl, { tex: [tex] });
    fbo.bind();
    gl.readPixels(0, 0, tex.size[0], tex.size[1], format, type, out);
    fbo.unbind();
    fbo.release();
    return out;
};