three.js/examples/js/loaders/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 = $.trim(line);
            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 = $.trim(value);
            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 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;
};