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/**
* @author daron1337 / http://daron1337.github.io/
*/
import {
Color
} from "../../../build/three.module.js";
var Lut = function ( colormap, numberofcolors ) {
this.lut = [];
this.setColorMap( colormap, numberofcolors );
return this;
};
Lut.prototype = {
constructor: Lut,
lut: [], map: [], n: 256, minV: 0, maxV: 1,
set: function ( value ) {
if ( value instanceof 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 = ColorMapKeywords[ colormap ] || 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 Color( this.map[ j ][ 1 ] );
var maxColor = new 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 ) {
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 Color( this.map[ j - 1 ][ 1 ] );
var maxColor = new 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;
}
};
var 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 ]]
};
export { Lut, ColorMapKeywords };
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