vtf-js/dist/formats/rgba.special.js

A javascript IO library for the Valve Texture Format.

import { VFormats } from '../core/enums.js';
import { VEncodedImageData, VImageData, registerCodec } from '../core/image.js';
/** Encodes a RGB888 Vec3 as a 565 16-bit int. @internal */
export function encode565(a, index = 0, r = 0, g = 1, b = 2) {
    return (((Math.round(a[index + r] / 0xff * 0b11111) << 11) & 0b1111100000000000) |
        ((Math.round(a[index + g] / 0xff * 0b111111) << 5) & 0b0000011111100000) |
        ((Math.round(a[index + b] / 0xff * 0b11111) << 0) & 0b0000000000011111));
}
/** Decodes a 16-bit int as an RGB323232F Vec3. @internal */
export function decode565(out, a, offset = 0, r = 0, g = 1, b = 2) {
    out[offset + r] = (((a & 0b1111100000000000) >> 11) / 0b11111);
    out[offset + g] = (((a & 0b0000011111100000) >> 5) / 0b111111);
    out[offset + b] = (((a & 0b0000000000011111) >> 0) / 0b11111);
    return out;
}
registerCodec(VFormats.RGB565, {
    length(width, height) {
        return width * height * 2;
    },
    encode(image) {
        const src = image.convert(Uint8Array).data;
        const pixels = image.width * image.height;
        const target = new Uint8Array(pixels * 2);
        const view = new DataView(target.buffer);
        for (let i = 0; i < pixels; i++) {
            view.setUint16(i * 2, encode565(src, i * 4), true);
        }
        return new VEncodedImageData(target, image.width, image.height, VFormats.RGB565);
    },
    decode(image) {
        const src = image.data;
        const pixels = image.width * image.height;
        const target = new Float32Array(pixels * 4);
        const view = new DataView(src.buffer);
        for (let i = 0; i < pixels; i++) {
            const d = i * 4;
            decode565(target, view.getUint16(i * 2, true), d);
            target[d + 3] = 1.0;
        }
        return new VImageData(target, image.width, image.height).convert(Uint8Array);
    }
});
registerCodec(VFormats.BGR565, {
    length(width, height) {
        return width * height * 2;
    },
    encode(image) {
        const src = image.convert(Uint8Array).data;
        const pixels = image.width * image.height;
        const target = new Uint8Array(pixels * 2);
        const view = new DataView(target.buffer);
        for (let i = 0; i < pixels; i++) {
            view.setUint16(i * 2, encode565(src, i * 4, 2, 1, 0), true);
        }
        return new VEncodedImageData(target, image.width, image.height, VFormats.RGB565);
    },
    decode(image) {
        const src = image.data;
        const pixels = image.width * image.height;
        const target = new Float32Array(pixels * 4);
        const view = new DataView(src.buffer);
        for (let i = 0; i < pixels; i++) {
            const d = i * 4;
            decode565(target, view.getUint16(i * 2, true), d, 2, 1, 0);
            target[d + 3] = 1.0;
        }
        return new VImageData(target, image.width, image.height).convert(Uint8Array);
    }
});
registerCodec(VFormats.IA88, {
    length(width, height) {
        return width * height * 2;
    },
    encode(image) {
        const pixels = image.width * image.height;
        const out = new Uint8Array(pixels * 2);
        const src = image.convert(Uint8Array).data;
        for (let i = 0; i < pixels; i++) {
            const s = i * 4;
            const t = i * 2;
            out[t] = src[s];
            out[t + 1] = src[s + 3];
        }
        return new VEncodedImageData(out, image.width, image.height, VFormats.IA88);
    },
    decode(image) {
        const pixels = image.width * image.height;
        const out = new Uint8Array(pixels * 4);
        const src = image.data;
        for (let i = 0; i < pixels; i++) {
            const s = i * 2;
            const t = i * 4;
            out[t] = out[t + 1] = out[t + 2] = src[s];
            out[t + 3] = src[s + 1];
        }
        return new VImageData(out, image.width, image.height);
    }
});