Method parse

src/loaders/LUT3dlLoader.js:92–162

* Parses the given data. * * @param {String} input - The LUT data. * @return {LookupTexture} The lookup texture. * @throws {Error} Fails if the data is invalid.

(input)

	 */

	parse(input) {

		const regExpGridInfo = /^[\d ]+$/m;
		const regExpDataPoints = /^([\d.e+-]+) +([\d.e+-]+) +([\d.e+-]+) *$/gm;

		// The first line describes the positions of values on the LUT grid.
		let result = regExpGridInfo.exec(input);

		if(result === null) {

			throw new Error("Missing grid information");

		}

		const gridLines = result[0].trim().split(/\s+/g).map((n) => Number(n));
		const gridStep = gridLines[1] - gridLines[0];
		const size = gridLines.length;
		const sizeSq = size ** 2;

		for(let i = 1, l = gridLines.length; i < l; ++i) {

			if(gridStep !== (gridLines[i] - gridLines[i - 1])) {

				throw new Error("Inconsistent grid size");

			}

		}

		const data = new Float32Array(size ** 3 * 4);
		let maxValue = 0.0;
		let index = 0;

		while((result = regExpDataPoints.exec(input)) !== null) {

			const r = Number(result[1]);
			const g = Number(result[2]);
			const b = Number(result[3]);

			maxValue = Math.max(maxValue, r, g, b);

			const bLayer = index % size;
			const gLayer = Math.floor(index / size) % size;
			const rLayer = Math.floor(index / (sizeSq)) % size;

			// b grows first, then g, then r.
			const d4 = (bLayer * sizeSq + gLayer * size + rLayer) * 4;
			data[d4 + 0] = r;
			data[d4 + 1] = g;
			data[d4 + 2] = b;
			data[d4 + 3] = 1.0;

			++index;

		}

		// Determine the bit depth and scale the values to [0.0, 1.0].
		const bits = Math.ceil(Math.log2(maxValue));