https://github.com/WWBN/AVideo/issues/8713

node_modules/three/examples/js/math/Lut.js

@@ -0,0 +1,181 @@
+THREE.Lut = function ( colormap, numberofcolors ) {
+
+	this.lut = [];
+	this.setColorMap( colormap, numberofcolors );
+	return this;
+
+};
+
+THREE.Lut.prototype = {
+
+	constructor: THREE.Lut,
+
+	lut: [], map: [], n: 256, minV: 0, maxV: 1,
+
+	set: function ( value ) {
+
+		if ( value instanceof THREE.Lut ) {
+
+			this.copy( value );
+
+		}
+
+		return this;
+
+	},
+
+	setMin: function ( min ) {
+
+		this.minV = min;
+
+		return this;
+
+	},
+
+	setMax: function ( max ) {
+
+		this.maxV = max;
+
+		return this;
+
+	},
+
+	setColorMap: function ( colormap, numberofcolors ) {
+
+		this.map = THREE.ColorMapKeywords[ colormap ] || THREE.ColorMapKeywords.rainbow;
+		this.n = numberofcolors || 32;
+
+		var step = 1.0 / this.n;
+
+		this.lut.length = 0;
+		for ( var i = 0; i <= 1; i += step ) {
+
+			for ( var j = 0; j < this.map.length - 1; j ++ ) {
+
+				if ( i >= this.map[ j ][ 0 ] && i < this.map[ j + 1 ][ 0 ] ) {
+
+					var min = this.map[ j ][ 0 ];
+					var max = this.map[ j + 1 ][ 0 ];
+
+					var minColor = new THREE.Color( this.map[ j ][ 1 ] );
+					var maxColor = new THREE.Color( this.map[ j + 1 ][ 1 ] );
+
+					var color = minColor.lerp( maxColor, ( i - min ) / ( max - min ) );
+
+					this.lut.push( color );
+
+				}
+
+			}
+
+		}
+
+		return this;
+
+	},
+
+	copy: function ( lut ) {
+
+		this.lut = lut.lut;
+		this.map = lut.map;
+		this.n = lut.n;
+		this.minV = lut.minV;
+		this.maxV = lut.maxV;
+
+		return this;
+
+	},
+
+	getColor: function ( alpha ) {
+
+		if ( alpha <= this.minV ) {
+
+			alpha = this.minV;
+
+		} else if ( alpha >= this.maxV ) {
+
+			alpha = this.maxV;
+
+		}
+
+		alpha = ( alpha - this.minV ) / ( this.maxV - this.minV );
+
+		var colorPosition = Math.round( alpha * this.n );
+		colorPosition == this.n ? colorPosition -= 1 : colorPosition;
+
+		return this.lut[ colorPosition ];
+
+	},
+
+	addColorMap: function ( colormapName, arrayOfColors ) {
+
+		THREE.ColorMapKeywords[ colormapName ] = arrayOfColors;
+
+	},
+
+	createCanvas: function () {
+
+		var canvas = document.createElement( 'canvas' );
+		canvas.width = 1;
+		canvas.height = this.n;
+
+		this.updateCanvas( canvas );
+
+		return canvas;
+
+	},
+
+	updateCanvas: function ( canvas ) {
+
+		var ctx = canvas.getContext( '2d', { alpha: false } );
+
+		var imageData = ctx.getImageData( 0, 0, 1, this.n );
+
+		var data = imageData.data;
+
+		var k = 0;
+
+		var step = 1.0 / this.n;
+
+		for ( var i = 1; i >= 0; i -= step ) {
+
+			for ( var j = this.map.length - 1; j >= 0; j -- ) {
+
+				if ( i < this.map[ j ][ 0 ] && i >= this.map[ j - 1 ][ 0 ] ) {
+
+					var min = this.map[ j - 1 ][ 0 ];
+					var max = this.map[ j ][ 0 ];
+
+					var minColor = new THREE.Color( this.map[ j - 1 ][ 1 ] );
+					var maxColor = new THREE.Color( this.map[ j ][ 1 ] );
+
+					var color = minColor.lerp( maxColor, ( i - min ) / ( max - min ) );
+
+					data[ k * 4 ] = Math.round( color.r * 255 );
+					data[ k * 4 + 1 ] = Math.round( color.g * 255 );
+					data[ k * 4 + 2 ] = Math.round( color.b * 255 );
+					data[ k * 4 + 3 ] = 255;
+
+					k += 1;
+
+				}
+
+			}
+
+		}
+
+		ctx.putImageData( imageData, 0, 0 );
+
+		return canvas;
+
+	}
+};
+
+THREE.ColorMapKeywords = {
+
+	'rainbow': [[ 0.0, 0x0000FF ], [ 0.2, 0x00FFFF ], [ 0.5, 0x00FF00 ], [ 0.8, 0xFFFF00 ], [ 1.0, 0xFF0000 ]],
+	'cooltowarm': [[ 0.0, 0x3C4EC2 ], [ 0.2, 0x9BBCFF ], [ 0.5, 0xDCDCDC ], [ 0.8, 0xF6A385 ], [ 1.0, 0xB40426 ]],
+	'blackbody': [[ 0.0, 0x000000 ], [ 0.2, 0x780000 ], [ 0.5, 0xE63200 ], [ 0.8, 0xFFFF00 ], [ 1.0, 0xFFFFFF ]],
+	'grayscale': [[ 0.0, 0x000000 ], [ 0.2, 0x404040 ], [ 0.5, 0x7F7F80 ], [ 0.8, 0xBFBFBF ], [ 1.0, 0xFFFFFF ]]
+
+};