MTLLoader.js

/**
 * Loads a Wavefront .mtl file specifying materials
 *
 * @author angelxuanchang
 */

THREE.MTLLoader = function( baseUrl, options ) {

    THREE.EventTarget.call( this );
    this.baseUrl = baseUrl;
    this.options = options;

};

THREE.MTLLoader.prototype = {

    /**
     * Loads a MTL file
     *
     * Loading progress is indicated by the following events:
     *   "load" event (successful loading): type = 'load', content = THREE.MTLLoader.MaterialCreator
     *   "error" event (error loading): type = 'load', message
     *   "progress" event (progress loading): type = 'progress', loaded, total
     *
     * @param url - location of MTL file
     */
    load: function( url ) {

        var scope = this;
        var xhr = new XMLHttpRequest();

        function onloaded( event ) {

            if ( event.target.status === 200 || event.target.status === 0 ) {

                var materialCreator = scope.parse( event.target.responseText );

                // Notify caller, that I'm done

                scope.dispatchEvent( { type: 'load', content: materialCreator } );

            } else {

                scope.dispatchEvent( { type: 'error', message: 'Couldn\'t load URL [' + url + ']',
                    response: event.target.responseText } );

            }

        }

        xhr.addEventListener( 'load', onloaded, false );

        xhr.addEventListener( 'progress', function ( event ) {

            scope.dispatchEvent( { type: 'progress', loaded: event.loaded, total: event.total } );

        }, false );

        xhr.addEventListener( 'error', function () {

            scope.dispatchEvent( { type: 'error', message: 'Couldn\'t load URL [' + url + ']' } );

        }, false );

        xhr.open( 'GET', url, true );
        xhr.send( null );
    },

    /**
     * Parses loaded MTL file
     * @param text - Content of MTL file
     * @return {THREE.MTLLoader.MaterialCreator}
     */
    parse: function( text ) {

        var lines = text.split( "\n" );
        var info = {};
        var delimiter_pattern = /\s+/;
        var materialsInfo = {};

			for ( var i = 0; i < lines.length; i ++ ) {

			var line = lines[ i ];
            line = line.trim();

            if ( line.length === 0 || line.charAt( 0 ) === '#' ) {

                // Blank line or comment ignore
                continue;

            }

            var pos = line.indexOf( ' ' );

			var key = ( pos >= 0 ) ? line.substring( 0, pos) : line;
            key = key.toLowerCase();

            var value = ( pos >= 0 ) ? line.substring( pos + 1 ) : "";
            value = value.trim();

            if ( key === "newmtl" ) {

                // New material

                info = { name: value };
                materialsInfo[ value ] = info;

            } else if ( info ) {

                if ( key === "ka" || key === "kd" || key === "ks" ) {

                    var ss = value.split( delimiter_pattern, 3 );
                    info[ key ] = [ parseFloat( ss[0] ), parseFloat( ss[1] ), parseFloat( ss[2] ) ];

                } else {

                    info[ key ] = value;

                }

            }

        }

        var materialCreator = new THREE.MTLLoader.MaterialCreator( this.baseUrl, this.options );
        materialCreator.setMaterials( materialsInfo );
        return materialCreator;

    }

};

/**
 * Create a new THREE-MTLLoader.MaterialCreator
 * @param baseUrl - Url relative to which textures are loaded
 * @param options - Set of options on how to construct the materials
 *                  side: Which side to apply the material
 *                        THREE.FrontSide (default), THREE.BackSide, THREE.DoubleSide
 *                  wrap: What type of wrapping to apply for textures
 *                        THREE.RepeatWrapping (default), THREE.ClampToEdgeWrapping, THREE.MirroredRepeatWrapping
 *                  normalizeRGB: RGBs need to be normalized to 0-1 from 0-255
 *                                Default: false, assumed to be already normalized
 *                  ignoreZeroRGBs: Ignore values of RGBs (Ka,Kd,Ks) that are all 0's
 *                                  Default: false
 *                  invertTransparency: If transparency need to be inverted (inversion is needed if d = 0 is fully opaque)
 *                                      Default: false (d = 1 is fully opaque)
 * @constructor
 */
THREE.MTLLoader.MaterialCreator = function( baseUrl, options ) {

    THREE.EventTarget.call( this );
    this.baseUrl = baseUrl;
    this.options = options;
    this.materialsInfo = {};
    this.materials = {};
    this.materialsArray = [];
    this.nameLookup = {};

    this.side = ( this.options && this.options.side )? this.options.side: THREE.FrontSide;
    this.wrap = ( this.options && this.options.wrap )? this.options.wrap: THREE.RepeatWrapping;

};

THREE.MTLLoader.MaterialCreator.prototype = {

    setMaterials: function( materialsInfo ) {

        this.materialsInfo = this.convert( materialsInfo );
        this.materials = {};
        this.materialsArray = [];
        this.nameLookup = {};

    },

    convert: function( materialsInfo ) {

        if ( !this.options ) return materialsInfo;

        var converted = {};

        for ( var mn in materialsInfo ) {

            // Convert materials info into normalized form based on options

            var mat = materialsInfo[ mn ];

            var covmat = {};

            converted[ mn ] = covmat;

            for ( var prop in mat ) {

                var save = true;
                var value = mat[ prop ];
                var lprop = prop.toLowerCase();

                switch ( lprop ) {

                    case 'kd':
                    case 'ka':
                    case 'ks':

                        // Diffuse color (color under white light) using RGB values

                        if ( this.options && this.options.normalizeRGB ) {

                            value =  [ value[0]/255, value[1]/255, value[2]/255 ];

                        }

                        if ( this.options && this.options.ignoreZeroRGBs ) {

                            if ( value[0] === 0.0 && value[1] === 0.0 && value[1] === 0.0 ) {

                                // ignore

                                save = false;

                            }
                        }

                        break;

                    case 'd':

                        // According to MTL format (http://paulbourke.net/dataformats/mtl/):
                        //   d is dissolve for current material
                        //   factor of 1.0 is fully opaque, a factor of 0 is fully dissolved (completely transparent)

                        if ( this.options && this.options.invertTransparency ) {

                            value = 1 - value;

                        }

                        break;

                    default:

                        break;
                }

                if ( save ) {

                    covmat[lprop] = value;

                }

            }

        }

        return converted;

    },

    preload: function () {

        for ( var mn in this.materialsInfo ) {

            this.create( mn );

        }

    },

    getIndex: function( materialName ) {

        return this.nameLookup[ materialName ];

    },

    getAsArray: function() {

        var index = 0;

        for ( var mn in this.materialsInfo ) {

            this.materialsArray[ index ] = this.create( mn );
            this.nameLookup[ mn ] = index;
            index ++;

        }

        return this.materialsArray;

    },

    create: function ( materialName ) {

        if ( this.materials[ materialName ] === undefined ) {

            this.createMaterial_( materialName );

        }

        return this.materials[ materialName ];

    },

    createMaterial_: function ( materialName ) {

        // Create material

        var mat = this.materialsInfo[ materialName ];
        var params = {

            name: materialName,
            side: this.side

        };

        for ( var prop in mat ) {

            var value = mat[ prop ];

            switch ( prop.toLowerCase() ) {

                // Ns is material specular exponent

                case 'kd':

					// Diffuse color (color under white light) using RGB values

					params[ 'diffuse' ] = new THREE.Color().setRGB( value[0], value[1], value[2] );

					break;

                case 'ka':

                    // Ambient color (color under shadow) using RGB values

                    params[ 'ambient' ] = new THREE.Color().setRGB( value[0], value[1], value[2] );

					break;

                case 'ks':

                    // Specular color (color when light is reflected from shiny surface) using RGB values
                    params[ 'specular' ] = new THREE.Color().setRGB( value[0], value[1], value[2] );

                    break;

                case 'map_kd':

                    // Diffuse texture map

                    params[ 'map' ] = THREE.MTLLoader.loadTexture( this.baseUrl + value );
                    params[ 'map' ].wrapS = this.wrap;
                    params[ 'map' ].wrapT = this.wrap;

					break;

                case 'ns':

                    // The specular exponent (defines the focus of the specular highlight)
                    // A high exponent results in a tight, concentrated highlight. Ns values normally range from 0 to 1000.

					params['shininess'] = value;

					break;

                case 'd':

                    // According to MTL format (http://paulbourke.net/dataformats/mtl/):
                    //   d is dissolve for current material
                    //   factor of 1.0 is fully opaque, a factor of 0 is fully dissolved (completely transparent)

                    if ( value < 1 ) {

                        params['transparent'] = true;
                        params['opacity'] = value;

                    }

                    break;

                default:
                    break;

            }

        }

        if ( params[ 'diffuse' ] ) {

            if ( !params[ 'ambient' ]) params[ 'ambient' ] = params[ 'diffuse' ];
            params[ 'color' ] = params[ 'diffuse' ];

        }

        this.materials[ materialName ] = new THREE.MeshPhongMaterial( params );
        return this.materials[ materialName ];

    }

};

THREE.MTLLoader.loadTexture = function ( url, mapping, onLoad, onError ) {

	var isCompressed = url.toLowerCase().endsWith( ".dds" );

	if ( isCompressed ) {

		var texture = THREE.ImageUtils.loadCompressedTexture( url, mapping, onLoad, onError );

	} else {

		var image = new Image();
		var texture = new THREE.Texture( image, mapping );

		var loader = new THREE.ImageLoader();

		loader.addEventListener( 'load', function ( event ) {

			texture.image = THREE.MTLLoader.ensurePowerOfTwo_( event.content );
			texture.needsUpdate = true;
			if ( onLoad ) onLoad( texture );

		} );

		loader.addEventListener( 'error', function ( event ) {

			if ( onError ) onError( event.message );

		} );

		loader.crossOrigin = this.crossOrigin;
		loader.load( url, image );

	}

	return texture;

};

THREE.MTLLoader.ensurePowerOfTwo_ = function ( image ) {

    if ( ! THREE.MTLLoader.isPowerOfTwo_( image.width ) || ! THREE.MTLLoader.isPowerOfTwo_( image.height ) ) {

        var canvas = document.createElement( "canvas" );
        canvas.width = THREE.MTLLoader.nextHighestPowerOfTwo_( image.width );
        canvas.height = THREE.MTLLoader.nextHighestPowerOfTwo_( image.height );

        var ctx = canvas.getContext("2d");
        ctx.drawImage( image, 0, 0, image.width, image.height, 0, 0, canvas.width, canvas.height );
        return canvas;

    }

    return image;

};

THREE.MTLLoader.isPowerOfTwo_ = function ( x ) {

	return ( x & ( x - 1 ) ) === 0;

};

THREE.MTLLoader.nextHighestPowerOfTwo_ = function( x ) {

    --x;

    for ( var i = 1; i < 32; i <<= 1 ) {

        x = x | x >> i;

    }

    return x + 1;

};