molstar/lib/commonjs/mol-util/float-packing.js

A comprehensive macromolecular library.

"use strict";
/**
 * Copyright (c) 2019-2020 mol* contributors, licensed under MIT, See LICENSE file for more info.
 *
 * @author Alexander Rose <alexander.rose@weirdbyte.de>
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.unpackRGBAToDepth = exports.decodeFloatRGB = exports.encodeFloatRGBtoArray = exports.decodeFloatLog = exports.encodeFloatLog = void 0;
var interpolate_1 = require("../mol-math/interpolate");
var approx_1 = require("../mol-math/approx");
var linear_algebra_1 = require("../mol-math/linear-algebra");
var maxFloat = 10000.0; // NOTE same constant is set in shaders
var floatLogFactor = (0, approx_1.fasterLog)(maxFloat + 1);
/** encode float logarithmically */
function encodeFloatLog(value) { return (0, approx_1.fasterLog)(value + 1) / floatLogFactor; }
exports.encodeFloatLog = encodeFloatLog;
/** decode logarithmically encoded float */
function decodeFloatLog(value) { return (0, approx_1.fasterExp)(value * floatLogFactor) - 1; }
exports.decodeFloatLog = decodeFloatLog;
/** encode float as rgb triplet into array at offset */
function encodeFloatRGBtoArray(value, array, offset) {
    value = (0, interpolate_1.clamp)(value, 0, 16777216 - 1) + 1;
    array[offset + 2] = value % 256;
    value = Math.floor(value / 256);
    array[offset + 1] = value % 256;
    value = Math.floor(value / 256);
    array[offset] = value % 256;
    return array;
}
exports.encodeFloatRGBtoArray = encodeFloatRGBtoArray;
/** decode float encoded as rgb triplet */
function decodeFloatRGB(r, g, b) {
    return (Math.floor(r) * 256 * 256 + Math.floor(g) * 256 + Math.floor(b)) - 1;
}
exports.decodeFloatRGB = decodeFloatRGB;
var UnpackDownscale = 255 / 256; // 0..1 -> fraction (excluding 1)
var PackFactors = linear_algebra_1.Vec3.create(256 * 256 * 256, 256 * 256, 256);
var UnpackFactors = linear_algebra_1.Vec4.create(UnpackDownscale / PackFactors[0], UnpackDownscale / PackFactors[1], UnpackDownscale / PackFactors[2], UnpackDownscale / 1);
var tmpDepthRGBA = (0, linear_algebra_1.Vec4)();
function unpackRGBAToDepth(r, g, b, a) {
    linear_algebra_1.Vec4.set(tmpDepthRGBA, r / 255, g / 255, b / 255, a / 255);
    return linear_algebra_1.Vec4.dot(tmpDepthRGBA, UnpackFactors);
}
exports.unpackRGBAToDepth = unpackRGBAToDepth;
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