mapbox-gl/src/shaders/encode_attribute.js

A WebGL interactive maps library

const util = require('../util/util');

/**
 * Packs two numbers, interpreted as 8-bit unsigned integers, into a single
 * float.  Unpack them in the shader using the `unpack_float()` function,
 * defined in _prelude.vertex.glsl
 *
 * @private
 */
exports.packUint8ToFloat = function pack(a, b) {
    // coerce a and b to 8-bit ints
    a = util.clamp(Math.floor(a), 0, 255);
    b = util.clamp(Math.floor(b), 0, 255);
    return 256 * a + b;
};