threemeshline.js

;(function() {

    "use strict";

    var root = this

    var has_require = typeof require !== 'undefined'

    var THREE = root.THREE || has_require && require('three')
    if( !THREE )
        throw new Error( 'MeshLine requires three.js' )

    function MeshLine() {

        this.positions = [];

        this.previous = [];
        this.next = [];
        this.side = [];
        this.width = [];
        this.indices_array = [];
        this.uvs = [];
        this.counters = [];
        this.geometry = new THREE.BufferGeometry();

        this.widthCallback = null;

    }

    MeshLine.prototype.setGeometry = function( g, c ) {

        this.widthCallback = c;

        this.positions = [];
        this.counters = [];

        if( g instanceof THREE.Geometry ) {
            for( var j = 0; j < g.vertices.length; j++ ) {
                var v = g.vertices[ j ];
                var c = j/g.vertices.length;
                this.positions.push( v.x, v.y, v.z );
                this.positions.push( v.x, v.y, v.z );
                this.counters.push(c);
                this.counters.push(c);
            }
        }

        if( g instanceof THREE.BufferGeometry ) {
            // read attribute positions ?
        }

        if( g instanceof Float32Array || g instanceof Array ) {
            for( var j = 0; j < g.length; j += 3 ) {
                var c = j/g.length;
                this.positions.push( g[ j ], g[ j + 1 ], g[ j + 2 ] );
                this.positions.push( g[ j ], g[ j + 1 ], g[ j + 2 ] );
                this.counters.push(c);
                this.counters.push(c);
            }
        }

        this.process();

    }

    MeshLine.prototype.compareV3 = function( a, b ) {

        var aa = a * 6;
        var ab = b * 6;
        return ( this.positions[ aa ] === this.positions[ ab ] ) && ( this.positions[ aa + 1 ] === this.positions[ ab + 1 ] ) && ( this.positions[ aa + 2 ] === this.positions[ ab + 2 ] );

    }

    MeshLine.prototype.copyV3 = function( a ) {

        var aa = a * 6;
        return [ this.positions[ aa ], this.positions[ aa + 1 ], this.positions[ aa + 2 ] ];

    }

    MeshLine.prototype.process = function() {

        var l = this.positions.length / 6;

        this.previous = [];
        this.next = [];
        this.side = [];
        this.width = [];
        this.indices_array = [];
        this.uvs = [];

        for( var j = 0; j < l; j++ ) {
            this.side.push( 1 );
            this.side.push( -1 );
        }

        var w;
        for( var j = 0; j < l; j++ ) {
            if( this.widthCallback ) w = this.widthCallback( j / ( l -1 ) );
            else w = 1;
            this.width.push( w );
            this.width.push( w );
        }

        for( var j = 0; j < l; j++ ) {
            this.uvs.push( j / ( l - 1 ), 0 );
            this.uvs.push( j / ( l - 1 ), 1 );
        }

        var v;

        if( this.compareV3( 0, l - 1 ) ){
            v = this.copyV3( l - 2 );
        } else {
            v = this.copyV3( 0 );
        }
        this.previous.push( v[ 0 ], v[ 1 ], v[ 2 ] );
        this.previous.push( v[ 0 ], v[ 1 ], v[ 2 ] );
        for( var j = 0; j < l - 1; j++ ) {
            v = this.copyV3( j );
            this.previous.push( v[ 0 ], v[ 1 ], v[ 2 ] );
            this.previous.push( v[ 0 ], v[ 1 ], v[ 2 ] );
        }

        for( var j = 1; j < l; j++ ) {
            v = this.copyV3( j );
            this.next.push( v[ 0 ], v[ 1 ], v[ 2 ] );
            this.next.push( v[ 0 ], v[ 1 ], v[ 2 ] );
        }

        if( this.compareV3( l - 1, 0 ) ){
            v = this.copyV3( 1 );
        } else {
            v = this.copyV3( l - 1 );
        }
        this.next.push( v[ 0 ], v[ 1 ], v[ 2 ] );
        this.next.push( v[ 0 ], v[ 1 ], v[ 2 ] );

        for( var j = 0; j < l - 1; j++ ) {
            var n = j * 2;
            this.indices_array.push( n, n + 1, n + 2 );
            this.indices_array.push( n + 2, n + 1, n + 3 );
        }

        if (!this.attributes) {
            this.attributes = {
                position: new THREE.BufferAttribute( new Float32Array( this.positions ), 3 ),
                previous: new THREE.BufferAttribute( new Float32Array( this.previous ), 3 ),
                next: new THREE.BufferAttribute( new Float32Array( this.next ), 3 ),
                side: new THREE.BufferAttribute( new Float32Array( this.side ), 1 ),
                width: new THREE.BufferAttribute( new Float32Array( this.width ), 1 ),
                uv: new THREE.BufferAttribute( new Float32Array( this.uvs ), 2 ),
                index: new THREE.BufferAttribute( new Uint16Array( this.indices_array ), 1 ),
                counters: new THREE.BufferAttribute( new Float32Array( this.counters ), 1 )
            }
        } else {
            this.attributes.position.copyArray(new Float32Array(this.positions));
            this.attributes.position.needsUpdate = true;
            this.attributes.previous.copyArray(new Float32Array(this.previous));
            this.attributes.previous.needsUpdate = true;
            this.attributes.next.copyArray(new Float32Array(this.next));
            this.attributes.next.needsUpdate = true;
            this.attributes.side.copyArray(new Float32Array(this.side));
            this.attributes.side.needsUpdate = true;
            this.attributes.width.copyArray(new Float32Array(this.width));
            this.attributes.width.needsUpdate = true;
            this.attributes.uv.copyArray(new Float32Array(this.uvs));
            this.attributes.uv.needsUpdate = true;
            this.attributes.index.copyArray(new Uint16Array(this.indices_array));
            this.attributes.index.needsUpdate = true;
        }

        this.geometry.addAttribute( 'position', this.attributes.position );
        this.geometry.addAttribute( 'previous', this.attributes.previous );
        this.geometry.addAttribute( 'next', this.attributes.next );
        this.geometry.addAttribute( 'side', this.attributes.side );
        this.geometry.addAttribute( 'width', this.attributes.width );
        this.geometry.addAttribute( 'uv', this.attributes.uv );
        this.geometry.addAttribute( 'counters', this.attributes.counters );

        this.geometry.setIndex( this.attributes.index );

    }

    function memcpy (src, srcOffset, dst, dstOffset, length) {
        var i

        src = src.subarray || src.slice ? src : src.buffer
        dst = dst.subarray || dst.slice ? dst : dst.buffer

        src = srcOffset ? src.subarray ?
            src.subarray(srcOffset, length && srcOffset + length) :
            src.slice(srcOffset, length && srcOffset + length) : src

        if (dst.set) {
            dst.set(src, dstOffset)
        } else {
            for (i=0; i<src.length; i++) {
                dst[i + dstOffset] = src[i]
            }
        }

        return dst
    }

    /**
     * Fast method to advance the line by one position.  The oldest position is removed.
     * @param position
     */
    MeshLine.prototype.advance = function(position) {

        var positions = this.attributes.position.array;
        var previous = this.attributes.previous.array;
        var next = this.attributes.next.array;
        var l = positions.length;

        // PREVIOUS
        memcpy( positions, 0, previous, 0, l );

        // POSITIONS
        memcpy( positions, 6, positions, 0, l - 6 );

        positions[l - 6] = position.x;
        positions[l - 5] = position.y;
        positions[l - 4] = position.z;
        positions[l - 3] = position.x;
        positions[l - 2] = position.y;
        positions[l - 1] = position.z;

        // NEXT
        memcpy( positions, 6, next, 0, l - 6 );

        next[l - 6]  = position.x;
        next[l - 5]  = position.y;
        next[l - 4]  = position.z;
        next[l - 3]  = position.x;
        next[l - 2]  = position.y;
        next[l - 1]  = position.z;

        this.attributes.position.needsUpdate = true;
        this.attributes.previous.needsUpdate = true;
        this.attributes.next.needsUpdate = true;

    };

    function MeshLineMaterial( parameters ) {

        var vertexShaderSource = [
            'precision highp float;',
            '',
            'attribute vec3 position;',
            'attribute vec3 previous;',
            'attribute vec3 next;',
            'attribute float side;',
            'attribute float width;',
            'attribute vec2 uv;',
            'attribute float counters;',
            '',
            'uniform mat4 projectionMatrix;',
            'uniform mat4 modelViewMatrix;',
            'uniform vec2 resolution;',
            'uniform float lineWidth;',
            'uniform vec3 color;',
            'uniform float opacity;',
            'uniform float near;',
            'uniform float far;',
            'uniform float sizeAttenuation;',
            '',
            'varying vec2 vUV;',
            'varying vec4 vColor;',
            'varying float vCounters;',
            '',
            'vec2 fix( vec4 i, float aspect ) {',
            '',
            '    vec2 res = i.xy / i.w;',
            '    res.x *= aspect;',
            '	 vCounters = counters;',
            '    return res;',
            '',
            '}',
            '',
            'void main() {',
            '',
            '    float aspect = resolution.x / resolution.y;',
            '	 float pixelWidthRatio = 1. / (resolution.x * projectionMatrix[0][0]);',
            '',
            '    vColor = vec4( color, opacity );',
            '    vUV = uv;',
            '',
            '    mat4 m = projectionMatrix * modelViewMatrix;',
            '    vec4 finalPosition = m * vec4( position, 1.0 );',
            '    vec4 prevPos = m * vec4( previous, 1.0 );',
            '    vec4 nextPos = m * vec4( next, 1.0 );',
            '',
            '    vec2 currentP = fix( finalPosition, aspect );',
            '    vec2 prevP = fix( prevPos, aspect );',
            '    vec2 nextP = fix( nextPos, aspect );',
            '',
            '	 float pixelWidth = finalPosition.w * pixelWidthRatio;',
            '    float w = 1.8 * pixelWidth * lineWidth * width;',
            '',
            '    if( sizeAttenuation == 1. ) {',
            '        w = 1.8 * lineWidth * width;',
            '    }',
            '',
            '    vec2 dir;',
            '    if( nextP == currentP ) dir = normalize( currentP - prevP );',
            '    else if( prevP == currentP ) dir = normalize( nextP - currentP );',
            '    else {',
            '        vec2 dir1 = normalize( currentP - prevP );',
            '        vec2 dir2 = normalize( nextP - currentP );',
            '        dir = normalize( dir1 + dir2 );',
            '',
            '        vec2 perp = vec2( -dir1.y, dir1.x );',
            '        vec2 miter = vec2( -dir.y, dir.x );',
            '        //w = clamp( w / dot( miter, perp ), 0., 4. * lineWidth * width );',
            '',
            '    }',
            '',
            '    //vec2 normal = ( cross( vec3( dir, 0. ), vec3( 0., 0., 1. ) ) ).xy;',
            '    vec2 normal = vec2( -dir.y, dir.x );',
            '    normal.x /= aspect;',
            '    normal *= .5 * w;',
            '',
            '    vec4 offset = vec4( normal * side, 0.0, 1.0 );',
            '    finalPosition.xy += offset.xy;',
            '',
            '    gl_Position = finalPosition;',
            '',
            '}' ];

        var fragmentShaderSource = [
            '#extension GL_OES_standard_derivatives : enable',
            'precision mediump float;',
            '',
            'uniform sampler2D map;',
            'uniform sampler2D alphaMap;',
            'uniform float useMap;',
            'uniform float useAlphaMap;',
            'uniform float useDash;',
            'uniform float dashArray;',
            'uniform float dashOffset;',
            'uniform float dashRatio;',
            'uniform float visibility;',
            'uniform float alphaTest;',
            'uniform vec2 repeat;',
            '',
            'varying vec2 vUV;',
            'varying vec4 vColor;',
            'varying float vCounters;',
            '',
            'void main() {',
            '',
            '    vec4 c = vColor;',
            '    if( useMap == 1. ) c *= texture2D( map, vUV * repeat );',
            '    if( useAlphaMap == 1. ) c.a *= texture2D( alphaMap, vUV * repeat ).a;',
            '    if( c.a < alphaTest ) discard;',
            '    if( useDash == 1. ){',
            '        c.a *= ceil(mod(vCounters + dashOffset, dashArray) - (dashArray * dashRatio));',
            '    }',
            '    gl_FragColor = c;',
            '    gl_FragColor.a *= step(vCounters, visibility);',
            '}' ];

        function check( v, d ) {
            if( v === undefined ) return d;
            return v;
        }

        THREE.Material.call( this );

        parameters = parameters || {};

        this.lineWidth = check( parameters.lineWidth, 1 );
        this.map = check( parameters.map, null );
        this.useMap = check( parameters.useMap, 0 );
        this.alphaMap = check( parameters.alphaMap, null );
        this.useAlphaMap = check( parameters.useAlphaMap, 0 );
        this.color = check( parameters.color, new THREE.Color( 0xffffff ) );
        this.opacity = check( parameters.opacity, 1 );
        this.resolution = check( parameters.resolution, new THREE.Vector2( 1, 1 ) );
        this.sizeAttenuation = check( parameters.sizeAttenuation, 1 );
        this.near = check( parameters.near, 1 );
        this.far = check( parameters.far, 1 );
        this.dashArray = check( parameters.dashArray, 0 );
        this.dashOffset = check( parameters.dashOffset, 0 );
        this.dashRatio = check( parameters.dashRatio, 0.5 );
        this.useDash = ( this.dashArray !== 0 ) ? 1 : 0;
        this.visibility = check( parameters.visibility, 1 );
        this.alphaTest = check( parameters.alphaTest, 0 );
        this.repeat = check( parameters.repeat, new THREE.Vector2( 1, 1 ) );

        var material = new THREE.RawShaderMaterial( {
            uniforms:{
                lineWidth: { type: 'f', value: this.lineWidth },
                map: { type: 't', value: this.map },
                useMap: { type: 'f', value: this.useMap },
                alphaMap: { type: 't', value: this.alphaMap },
                useAlphaMap: { type: 'f', value: this.useAlphaMap },
                color: { type: 'c', value: this.color },
                opacity: { type: 'f', value: this.opacity },
                resolution: { type: 'v2', value: this.resolution },
                sizeAttenuation: { type: 'f', value: this.sizeAttenuation },
                near: { type: 'f', value: this.near },
                far: { type: 'f', value: this.far },
                dashArray: { type: 'f', value: this.dashArray },
                dashOffset: { type: 'f', value: this.dashOffset },
                dashRatio: { type: 'f', value: this.dashRatio },
                useDash: { type: 'f', value: this.useDash },
                visibility: {type: 'f', value: this.visibility},
                alphaTest: {type: 'f', value: this.alphaTest},
                repeat: { type: 'v2', value: this.repeat }
            },
            vertexShader: vertexShaderSource.join( '\r\n' ),
            fragmentShader: fragmentShaderSource.join( '\r\n' )
        });

        delete parameters.lineWidth;
        delete parameters.map;
        delete parameters.useMap;
        delete parameters.alphaMap;
        delete parameters.useAlphaMap;
        delete parameters.color;
        delete parameters.opacity;
        delete parameters.resolution;
        delete parameters.sizeAttenuation;
        delete parameters.near;
        delete parameters.far;
        delete parameters.dashArray;
        delete parameters.dashOffset;
        delete parameters.dashRatio;
        delete parameters.visibility;
        delete parameters.alphaTest;
        delete parameters.repeat;

        material.type = 'MeshLineMaterial';

        material.setValues( parameters );

        return material;

    };

    MeshLineMaterial.prototype = Object.create( THREE.Material.prototype );
    MeshLineMaterial.prototype.constructor = MeshLineMaterial;

    MeshLineMaterial.prototype.copy = function ( source ) {

        THREE.Material.prototype.copy.call( this, source );

        this.lineWidth = source.lineWidth;
        this.map = source.map;
        this.useMap = source.useMap;
        this.alphaMap = source.alphaMap;
        this.useAlphaMap = source.useAlphaMap;
        this.color.copy( source.color );
        this.opacity = source.opacity;
        this.resolution.copy( source.resolution );
        this.sizeAttenuation = source.sizeAttenuation;
        this.near = source.near;
        this.far = source.far;
        this.dashArray.copy( source.dashArray );
        this.dashOffset.copy( source.dashOffset );
        this.dashRatio.copy( source.dashRatio );
        this.useDash = source.useDash;
        this.visibility = source.visibility;
        this.alphaTest = source.alphaTest;
        this.repeat.copy( source.repeat );

        return this;

    };

    if( typeof exports !== 'undefined' ) {
        if( typeof module !== 'undefined' && module.exports ) {
            exports = module.exports = { MeshLine: MeshLine, MeshLineMaterial: MeshLineMaterial };
        }
        exports.MeshLine = MeshLine;
        exports.MeshLineMaterial = MeshLineMaterial;
    }
    else {
        root.MeshLine = MeshLine;
        root.MeshLineMaterial = MeshLineMaterial;
    }

}).call(this);