IESLoader.js

import { FileLoader } from './FileLoader';
import { DataTexture } from '../textures/DataTexture';
import { DefaultLoadingManager } from './LoadingManager';
import { _Math } from '../math/Math';

function IESLoader(manager) {

	this.manager = (manager !== undefined) ? manager : DefaultLoadingManager;

}

function IESLamp(text) {

	var _self = this;

	var textArray = text.split('\n');

	var lineNumber = 0;
	var line;

	_self.verAngles = [];
	_self.horAngles = [];
	_self.candelaValues = [];
	_self.tiltData = {};
	_self.tiltData.angles = [];
	_self.tiltData.mulFactors = [];

	function textToArray(text) {
		text = text.replace(/^\s+|\s+$/g, '');// remove leading or trailing spaces
		text = text.replace(/,/g, ' ');// replace commas with spaces
		text = text.replace(/\s\s+/g, ' '); // Replcae white space/tabs etc by single whitespace
		var array = text.split(' ');
		return array;
	}

	function readArray(count, array) {
		while (true) {
			var line = textArray[lineNumber++];
			var lineData = textToArray(line);
			for (var i = 0; i < lineData.length; ++i) {
				array.push(Number(lineData[i]));
			}
			if (array.length === count)
				break;
		}
	}

	function readTilt() {
		var line = textArray[lineNumber++];
		var lineData = textToArray(line);
		_self.tiltData.lampToLumGeometry = Number(lineData[0]);
		line = textArray[lineNumber++];
		lineData = textToArray(line);
		_self.tiltData.numAngles = Number(lineData[0]);
		readArray(_self.tiltData.numAngles, _self.tiltData.angles);
		readArray(_self.tiltData.numAngles, _self.tiltData.mulFactors);
	}

	function readLampValues() {
		var values = [];
		readArray(10, values);

		_self.count = Number(values[0]);
		_self.lumens = Number(values[1]);
		_self.multiplier = Number(values[2]);
		_self.numVerAngles = Number(values[3]);
		_self.numHorAngles = Number(values[4]);
		_self.gonioType = Number(values[5]);
		_self.units = Number(values[6]);
		_self.width = Number(values[7]);
		_self.length = Number(values[8]);
		_self.height = Number(values[9]);
	}

	function readLampFactors() {
		var values = [];
		readArray(3, values);

		_self.ballFactor = Number(values[0]);
		_self.blpFactor = Number(values[1]);
		_self.inputWatts = Number(values[2]);
	}


	while (true) {
		var line = textArray[lineNumber++];

		if (line.includes('TILT')) {
			break;
		}
	}

	if (!line.includes('NONE')) {
		if (line.includes('INCLUDE')) {
			readTilt();
		} else {
			// TODO:: Read tilt data from a file
		}
	}

	readLampValues();

	readLampFactors();

	// Initialize candela value array
	for (var i = 0; i < _self.numHorAngles; ++i) {
		_self.candelaValues.push([]);
	}

	// Parse Angles
	readArray(_self.numVerAngles, _self.verAngles);
	readArray(_self.numHorAngles, _self.horAngles);

	// Parse Candela values
	for (var i = 0; i < _self.numHorAngles; ++i) {
		readArray(_self.numVerAngles, _self.candelaValues[i]);
	}

	// Calculate actual candela values, and normalize.
	for (var i = 0; i < _self.numHorAngles; ++i) {
		for (var j = 0; j < _self.numVerAngles; ++j) {
			_self.candelaValues[i][j] *= _self.candelaValues[i][j] * _self.multiplier
				* _self.ballFactor * _self.blpFactor;
		}
	}
	var maxVal = -1;
	for (var i = 0; i < _self.numHorAngles; ++i) {
		for (var j = 0; j < _self.numVerAngles; ++j) {
			var value = _self.candelaValues[i][j];
			maxVal = maxVal < value ? value : maxVal;
		}
	}

	var bNormalize = true;

	if (bNormalize && maxVal > 0) {
		for (var i = 0; i < _self.numHorAngles; ++i) {
			for (var j = 0; j < _self.numVerAngles; ++j) {
				_self.candelaValues[i][j] /= maxVal;
			}
		}
	}


}

Object.assign(IESLoader.prototype, {

	_parseIESData: function (text) {

		var iesLamp = new IESLamp(text);

		return iesLamp;
	},

	_getIESValues: function (iesLamp) {
		var width = 360; var height = 180;
		var size = width * height;
		var data = new Uint8Array(size);

		function interpolateCandelaValues(phi, theta) {

			var phiIndex = 0, thetaIndex = 0;
			var startTheta = 0, endTheta = 0, startPhi = 0, endPhi = 0;

			for (var i = 0; i < iesLamp.numHorAngles - 1; ++i) { // numHorAngles = horAngles.length-1 because of extra padding, so this wont cause an out of bounds error
				if (theta < iesLamp.horAngles[i + 1] || i == iesLamp.numHorAngles - 2) {
					thetaIndex = i;
					startTheta = iesLamp.horAngles[i];
					endTheta = iesLamp.horAngles[i + 1];
					break;
				}
			}
			for (var i = 0; i < iesLamp.numVerAngles - 1; ++i) {
				if (phi < iesLamp.verAngles[i + 1] || i == iesLamp.numVerAngles - 2) {
					phiIndex = i;
					startPhi = iesLamp.verAngles[i];
					endPhi = iesLamp.verAngles[i + 1];
					break;
				}
			}

			var deltaTheta = endTheta - startTheta;
			var deltaPhi = endPhi - startPhi;

			if (deltaPhi === 0) // Outside range
				return 0;

			var t1 = deltaTheta === 0 ? 0 : (theta - startTheta) / deltaTheta;
			var t2 = (phi - startPhi) / deltaPhi;

			var nextThetaIndex = deltaTheta === 0 ? thetaIndex : thetaIndex + 1;

			var v1 = _Math.lerp(iesLamp.candelaValues[thetaIndex][phiIndex], iesLamp.candelaValues[nextThetaIndex][phiIndex], t1);
			var v2 = _Math.lerp(iesLamp.candelaValues[thetaIndex][phiIndex + 1], iesLamp.candelaValues[nextThetaIndex][phiIndex + 1], t1);
			var v = _Math.lerp(v1, v2, t2);

			return Math.floor(v * 255);
		}

		var startTheta = iesLamp.horAngles[0], endTheta = iesLamp.horAngles[iesLamp.numHorAngles - 1];
		for (var i = 0; i < size; ++i) {
			var theta = i % width;
			var phi = Math.floor(i / width);

			if (endTheta - startTheta !== 0 && (theta < startTheta || theta >= endTheta)) { // Handle symmetry for hor angles
				theta %= endTheta * 2;
				if (theta > endTheta)
					theta = endTheta * 2 - theta;
			}

			data[i] = interpolateCandelaValues(phi, theta);
		}

		return data;
	},

	load: function (url, onLoad, onProgress, onError) {

		var loader = new FileLoader(this.manager);
		loader.setResponseType('text');
		var _self = this;

		var texture = new THREE.DataTexture(null, 360, 180, THREE.LuminanceFormat);
		texture.minFilter = THREE.LinearFilter;
		texture.magFilter = THREE.LinearFilter;

		loader.load(url, function (text) {

			var iesLamp = _self._parseIESData(text);

			texture.image.data = _self._getIESValues(iesLamp);
			texture.needsUpdate = true;

			if (onLoad !== undefined) {

				onLoad(texture);

			}

		}, onProgress, onError);

		return texture;

	}

});


export { IESLoader };