/**

* @author mrdoob / http://mrdoob.com/

*/

THREE.SpriteCanvasMaterial = function ( parameters ) {

THREE.Material.call( this );

this.type = 'SpriteCanvasMaterial';

this.color = new THREE.Color( 0xffffff );

this.program = function ( context, color ) {};

this.setValues( parameters );

};

THREE.SpriteCanvasMaterial.prototype = Object.create( THREE.Material.prototype );

THREE.SpriteCanvasMaterial.prototype.constructor = THREE.SpriteCanvasMaterial;

THREE.SpriteCanvasMaterial.prototype.clone = function () {

var material = new THREE.SpriteCanvasMaterial();

material.copy( this );

material.color.copy( this.color );

material.program = this.program;

return material;

};

//

THREE.CanvasRenderer = function ( parameters ) {

console.log( 'THREE.CanvasRenderer', THREE.REVISION );

parameters = parameters || {};

var _this = this,

_renderData, _elements, _lights,

_projector = new THREE.Projector(),

_canvas = parameters.canvas !== undefined

? parameters.canvas

: document.createElement( 'canvas' ),

_canvasWidth = _canvas.width,

_canvasHeight = _canvas.height,

_canvasWidthHalf = Math.floor( _canvasWidth / 2 ),

_canvasHeightHalf = Math.floor( _canvasHeight / 2 ),

_viewportX = 0,

_viewportY = 0,

_viewportWidth = _canvasWidth,

_viewportHeight = _canvasHeight,

_pixelRatio = 1,

_context = _canvas.getContext( '2d', {

alpha: parameters.alpha === true

} ),

_clearColor = new THREE.Color( 0x000000 ),

_clearAlpha = parameters.alpha === true ? 0 : 1,

_contextGlobalAlpha = 1,

_contextGlobalCompositeOperation = 0,

_contextStrokeStyle = null,

_contextFillStyle = null,

_contextLineWidth = null,

_contextLineCap = null,

_contextLineJoin = null,

_contextLineDash = [],

_camera,

_v1, _v2, _v3, _v4,

_v5 = new THREE.RenderableVertex(),

_v6 = new THREE.RenderableVertex(),

_v1x, _v1y, _v2x, _v2y, _v3x, _v3y,

_v4x, _v4y, _v5x, _v5y, _v6x, _v6y,

_color = new THREE.Color(),

_color1 = new THREE.Color(),

_color2 = new THREE.Color(),

_color3 = new THREE.Color(),

_color4 = new THREE.Color(),

_diffuseColor = new THREE.Color(),

_emissiveColor = new THREE.Color(),

_lightColor = new THREE.Color(),

_patterns = {},

_image, _uvs,

_uv1x, _uv1y, _uv2x, _uv2y, _uv3x, _uv3y,

_clipBox = new THREE.Box2(),

_clearBox = new THREE.Box2(),

_elemBox = new THREE.Box2(),

_ambientLight = new THREE.Color(),

_directionalLights = new THREE.Color(),

_pointLights = new THREE.Color(),

_vector3 = new THREE.Vector3(), // Needed for PointLight

_centroid = new THREE.Vector3(),

_normal = new THREE.Vector3(),

_normalViewMatrix = new THREE.Matrix3();

/* TODO

_canvas.mozImageSmoothingEnabled = false;

_canvas.webkitImageSmoothingEnabled = false;

_canvas.msImageSmoothingEnabled = false;

_canvas.imageSmoothingEnabled = false;

*/

// dash+gap fallbacks for Firefox and everything else

if ( _context.setLineDash === undefined ) {

_context.setLineDash = function () {};

}

this.domElement = _canvas;

this.autoClear = true;

this.sortObjects = true;

this.sortElements = true;

this.info = {

render: {

vertices: 0,

faces: 0

}

};

// WebGLRenderer compatibility

this.supportsVertexTextures = function () {};

this.setFaceCulling = function () {};

// API

this.getContext = function () {

return _context;

};

this.getContextAttributes = function () {

return _context.getContextAttributes();

};

this.getPixelRatio = function () {

return _pixelRatio;

};

this.setPixelRatio = function ( value ) {

if ( value !== undefined ) _pixelRatio = value;

};

this.setSize = function ( width, height, updateStyle ) {

_canvasWidth = width * _pixelRatio;

_canvasHeight = height * _pixelRatio;

_canvas.width = _canvasWidth;

_canvas.height = _canvasHeight;

_canvasWidthHalf = Math.floor( _canvasWidth / 2 );

_canvasHeightHalf = Math.floor( _canvasHeight / 2 );

if ( updateStyle !== false ) {

_canvas.style.width = width + 'px';

_canvas.style.height = height + 'px';

}

_clipBox.min.set( - _canvasWidthHalf, - _canvasHeightHalf );

_clipBox.max.set( _canvasWidthHalf, _canvasHeightHalf );

_clearBox.min.set( - _canvasWidthHalf, - _canvasHeightHalf );

_clearBox.max.set( _canvasWidthHalf, _canvasHeightHalf );

_contextGlobalAlpha = 1;

_contextGlobalCompositeOperation = 0;

_contextStrokeStyle = null;

_contextFillStyle = null;

_contextLineWidth = null;

_contextLineCap = null;

_contextLineJoin = null;

this.setViewport( 0, 0, width, height );

};

this.setViewport = function ( x, y, width, height ) {

_viewportX = x * _pixelRatio;

_viewportY = y * _pixelRatio;

_viewportWidth = width * _pixelRatio;

_viewportHeight = height * _pixelRatio;

};

this.setScissor = function () {};

this.setScissorTest = function () {};

this.setClearColor = function ( color, alpha ) {

_clearColor.set( color );

_clearAlpha = alpha !== undefined ? alpha : 1;

_clearBox.min.set( - _canvasWidthHalf, - _canvasHeightHalf );

_clearBox.max.set( _canvasWidthHalf, _canvasHeightHalf );

};

this.setClearColorHex = function ( hex, alpha ) {

console.warn( 'THREE.CanvasRenderer: .setClearColorHex() is being removed. Use .setClearColor() instead.' );

this.setClearColor( hex, alpha );

};

this.getClearColor = function () {

return _clearColor;

};

this.getClearAlpha = function () {

return _clearAlpha;

};

this.getMaxAnisotropy = function () {

return 0;

};

this.clear = function () {

if ( _clearBox.isEmpty() === false ) {

_clearBox.intersect( _clipBox );

_clearBox.expandByScalar( 2 );

_clearBox.min.x = _clearBox.min.x + _canvasWidthHalf;

_clearBox.min.y = - _clearBox.min.y + _canvasHeightHalf; // higher y value !

_clearBox.max.x = _clearBox.max.x + _canvasWidthHalf;

_clearBox.max.y = - _clearBox.max.y + _canvasHeightHalf; // lower y value !

if ( _clearAlpha < 1 ) {

_context.clearRect(

_clearBox.min.x | 0,

_clearBox.max.y | 0,

( _clearBox.max.x - _clearBox.min.x ) | 0,

( _clearBox.min.y - _clearBox.max.y ) | 0

);

}

if ( _clearAlpha > 0 ) {

setBlending( THREE.NormalBlending );

setOpacity( 1 );

setFillStyle( 'rgba(' + Math.floor( _clearColor.r * 255 ) + ',' + Math.floor( _clearColor.g * 255 ) + ',' + Math.floor( _clearColor.b * 255 ) + ',' + _clearAlpha + ')' );

_context.fillRect(

_clearBox.min.x | 0,

_clearBox.max.y | 0,

( _clearBox.max.x - _clearBox.min.x ) | 0,

( _clearBox.min.y - _clearBox.max.y ) | 0

);

}

_clearBox.makeEmpty();

}

};

// compatibility

this.clearColor = function () {};

this.clearDepth = function () {};

this.clearStencil = function () {};

this.render = function ( scene, camera ) {

if ( camera instanceof THREE.Camera === false ) {

console.error( 'THREE.CanvasRenderer.render: camera is not an instance of THREE.Camera.' );

return;

}

if ( this.autoClear === true ) this.clear();

_this.info.render.vertices = 0;

_this.info.render.faces = 0;

_context.setTransform( _viewportWidth / _canvasWidth, 0, 0, - _viewportHeight / _canvasHeight, _viewportX, _canvasHeight - _viewportY );

_context.translate( _canvasWidthHalf, _canvasHeightHalf );

_renderData = _projector.projectScene( scene, camera, this.sortObjects, this.sortElements );

_elements = _renderData.elements;

_lights = _renderData.lights;

_camera = camera;

_normalViewMatrix.getNormalMatrix( camera.matrixWorldInverse );

/* DEBUG

setFillStyle( 'rgba( 0, 255, 255, 0.5 )' );

_context.fillRect( _clipBox.min.x, _clipBox.min.y, _clipBox.max.x - _clipBox.min.x, _clipBox.max.y - _clipBox.min.y );

*/

calculateLights();

for ( var e = 0, el = _elements.length; e < el; e ++ ) {

var element = _elements[ e ];

var material = element.material;

if ( material === undefined || material.opacity === 0 ) continue;

_elemBox.makeEmpty();

if ( element instanceof THREE.RenderableSprite ) {

_v1 = element;

_v1.x *= _canvasWidthHalf; _v1.y *= _canvasHeightHalf;

renderSprite( _v1, element, material );

} else if ( element instanceof THREE.RenderableLine ) {

_v1 = element.v1; _v2 = element.v2;

_v1.positionScreen.x *= _canvasWidthHalf; _v1.positionScreen.y *= _canvasHeightHalf;

_v2.positionScreen.x *= _canvasWidthHalf; _v2.positionScreen.y *= _canvasHeightHalf;

_elemBox.setFromPoints( [

_v1.positionScreen,

_v2.positionScreen

] );

if ( _clipBox.intersectsBox( _elemBox ) === true ) {

renderLine( _v1, _v2, element, material );

}

} else if ( element instanceof THREE.RenderableFace ) {

_v1 = element.v1; _v2 = element.v2; _v3 = element.v3;

if ( _v1.positionScreen.z < - 1 || _v1.positionScreen.z > 1 ) continue;

if ( _v2.positionScreen.z < - 1 || _v2.positionScreen.z > 1 ) continue;

if ( _v3.positionScreen.z < - 1 || _v3.positionScreen.z > 1 ) continue;

_v1.positionScreen.x *= _canvasWidthHalf; _v1.positionScreen.y *= _canvasHeightHalf;

_v2.positionScreen.x *= _canvasWidthHalf; _v2.positionScreen.y *= _canvasHeightHalf;

_v3.positionScreen.x *= _canvasWidthHalf; _v3.positionScreen.y *= _canvasHeightHalf;

if ( material.overdraw > 0 ) {

expand( _v1.positionScreen, _v2.positionScreen, material.overdraw );

expand( _v2.positionScreen, _v3.positionScreen, material.overdraw );

expand( _v3.positionScreen, _v1.positionScreen, material.overdraw );

}

_elemBox.setFromPoints( [

_v1.positionScreen,

_v2.positionScreen,

_v3.positionScreen

] );

if ( _clipBox.intersectsBox( _elemBox ) === true ) {

renderFace3( _v1, _v2, _v3, 0, 1, 2, element, material );

}

}

/* DEBUG

setLineWidth( 1 );

setStrokeStyle( 'rgba( 0, 255, 0, 0.5 )' );

_context.strokeRect( _elemBox.min.x, _elemBox.min.y, _elemBox.max.x - _elemBox.min.x, _elemBox.max.y - _elemBox.min.y );

*/

_clearBox.union( _elemBox );

}

/* DEBUG

setLineWidth( 1 );

setStrokeStyle( 'rgba( 255, 0, 0, 0.5 )' );

_context.strokeRect( _clearBox.min.x, _clearBox.min.y, _clearBox.max.x - _clearBox.min.x, _clearBox.max.y - _clearBox.min.y );

*/

_context.setTransform( 1, 0, 0, 1, 0, 0 );

};

//

function calculateLights() {

_ambientLight.setRGB( 0, 0, 0 );

_directionalLights.setRGB( 0, 0, 0 );

_pointLights.setRGB( 0, 0, 0 );

for ( var l = 0, ll = _lights.length; l < ll; l ++ ) {

var light = _lights[ l ];

var lightColor = light.color;

if ( light instanceof THREE.AmbientLight ) {

_ambientLight.add( lightColor );

} else if ( light instanceof THREE.DirectionalLight ) {

// for sprites

_directionalLights.add( lightColor );

} else if ( light instanceof THREE.PointLight ) {

// for sprites

_pointLights.add( lightColor );

}

}

}

function calculateLight( position, normal, color ) {

for ( var l = 0, ll = _lights.length; l < ll; l ++ ) {

var light = _lights[ l ];

_lightColor.copy( light.color );

if ( light instanceof THREE.DirectionalLight ) {

var lightPosition = _vector3.setFromMatrixPosition( light.matrixWorld ).normalize();

var amount = normal.dot( lightPosition );

if ( amount <= 0 ) continue;

amount *= light.intensity;

color.add( _lightColor.multiplyScalar( amount ) );

} else if ( light instanceof THREE.PointLight ) {

var lightPosition = _vector3.setFromMatrixPosition( light.matrixWorld );

var amount = normal.dot( _vector3.subVectors( lightPosition, position ).normalize() );

if ( amount <= 0 ) continue;

amount *= light.distance == 0 ? 1 : 1 - Math.min( position.distanceTo( lightPosition ) / light.distance, 1 );

if ( amount == 0 ) continue;

amount *= light.intensity;

color.add( _lightColor.multiplyScalar( amount ) );

}

}

}

function renderSprite( v1, element, material ) {

setOpacity( material.opacity );

setBlending( material.blending );

var scaleX = element.scale.x * _canvasWidthHalf;

var scaleY = element.scale.y * _canvasHeightHalf;

var dist = 0.5 * Math.sqrt( scaleX * scaleX + scaleY * scaleY ); // allow for rotated sprite

_elemBox.min.set( v1.x - dist, v1.y - dist );

_elemBox.max.set( v1.x + dist, v1.y + dist );

if ( material instanceof THREE.SpriteMaterial ) {

var texture = material.map;

if ( texture !== null ) {

var pattern = _patterns[ texture.id ];

if ( pattern === undefined || pattern.version !== texture.version ) {

pattern = textureToPattern( texture );

_patterns[ texture.id ] = pattern;

}

if ( pattern.canvas !== undefined ) {

setFillStyle( pattern.canvas );

var bitmap = texture.image;

var ox = bitmap.width * texture.offset.x;

var oy = bitmap.height * texture.offset.y;

var sx = bitmap.width * texture.repeat.x;

var sy = bitmap.height * texture.repeat.y;

var cx = scaleX / sx;

var cy = scaleY / sy;

_context.save();

_context.translate( v1.x, v1.y );

if ( material.rotation !== 0 ) _context.rotate( material.rotation );

_context.translate( - scaleX / 2, - scaleY / 2 );

_context.scale( cx, cy );

_context.translate( - ox, - oy );

_context.fillRect( ox, oy, sx, sy );

_context.restore();

}

} else {

// no texture

setFillStyle( material.color.getStyle() );

_context.save();

_context.translate( v1.x, v1.y );

if ( material.rotation !== 0 ) _context.rotate( material.rotation );

_context.scale( scaleX, - scaleY );

_context.fillRect( - 0.5, - 0.5, 1, 1 );

_context.restore();

}

} else if ( material instanceof THREE.SpriteCanvasMaterial ) {

setStrokeStyle( material.color.getStyle() );

setFillStyle( material.color.getStyle() );

_context.save();

_context.translate( v1.x, v1.y );

if ( material.rotation !== 0 ) _context.rotate( material.rotation );

_context.scale( scaleX, scaleY );

material.program( _context );

_context.restore();

}

/* DEBUG

setStrokeStyle( 'rgb(255,255,0)' );

_context.beginPath();

_context.moveTo( v1.x - 10, v1.y );

_context.lineTo( v1.x + 10, v1.y );

_context.moveTo( v1.x, v1.y - 10 );

_context.lineTo( v1.x, v1.y + 10 );

_context.stroke();

*/

}

function renderLine( v1, v2, element, material ) {

setOpacity( material.opacity );

setBlending( material.blending );

_context.beginPath();

_context.moveTo( v1.positionScreen.x, v1.positionScreen.y );

_context.lineTo( v2.positionScreen.x, v2.positionScreen.y );

if ( material instanceof THREE.LineBasicMaterial ) {

setLineWidth( material.linewidth );

setLineCap( material.linecap );

setLineJoin( material.linejoin );

if ( material.vertexColors !== THREE.VertexColors ) {

setStrokeStyle( material.color.getStyle() );

} else {

var colorStyle1 = element.vertexColors[ 0 ].getStyle();

var colorStyle2 = element.vertexColors[ 1 ].getStyle();

if ( colorStyle1 === colorStyle2 ) {

setStrokeStyle( colorStyle1 );

} else {

try {

var grad = _context.createLinearGradient(

v1.positionScreen.x,

v1.positionScreen.y,

v2.positionScreen.x,

v2.positionScreen.y

);

grad.addColorStop( 0, colorStyle1 );

grad.addColorStop( 1, colorStyle2 );

} catch ( exception ) {

grad = colorStyle1;

}

setStrokeStyle( grad );

}

}

_context.stroke();

_elemBox.expandByScalar( material.linewidth * 2 );

} else if ( material instanceof THREE.LineDashedMaterial ) {

setLineWidth( material.linewidth );

setLineCap( material.linecap );

setLineJoin( material.linejoin );

setStrokeStyle( material.color.getStyle() );

setLineDash( [ material.dashSize, material.gapSize ] );

_context.stroke();

_elemBox.expandByScalar( material.linewidth * 2 );

setLineDash( [] );

}

}

function renderFace3( v1, v2, v3, uv1, uv2, uv3, element, material ) {

_this.info.render.vertices += 3;

_this.info.render.faces ++;

setOpacity( material.opacity );

setBlending( material.blending );

_v1x = v1.positionScreen.x; _v1y = v1.positionScreen.y;

_v2x = v2.positionScreen.x; _v2y = v2.positionScreen.y;

_v3x = v3.positionScreen.x; _v3y = v3.positionScreen.y;

drawTriangle( _v1x, _v1y, _v2x, _v2y, _v3x, _v3y );

if ( ( material instanceof THREE.MeshLambertMaterial || material instanceof THREE.MeshPhongMaterial ) && material.map === null ) {

_diffuseColor.copy( material.color );

_emissiveColor.copy( material.emissive );

if ( material.vertexColors === THREE.FaceColors ) {

_diffuseColor.multiply( element.color );

}

_color.copy( _ambientLight );

_centroid.copy( v1.positionWorld ).add( v2.positionWorld ).add( v3.positionWorld ).divideScalar( 3 );

calculateLight( _centroid, element.normalModel, _color );

_color.multiply( _diffuseColor ).add( _emissiveColor );

material.wireframe === true

? strokePath( _color, material.wireframeLinewidth, material.wireframeLinecap, material.wireframeLinejoin )

: fillPath( _color );

} else if ( material instanceof THREE.MeshBasicMaterial ||

material instanceof THREE.MeshLambertMaterial ||

material instanceof THREE.MeshPhongMaterial ) {

if ( material.map !== null ) {

var mapping = material.map.mapping;

if ( mapping === THREE.UVMapping ) {

_uvs = element.uvs;

patternPath( _v1x, _v1y, _v2x, _v2y, _v3x, _v3y, _uvs[ uv1 ].x, _uvs[ uv1 ].y, _uvs[ uv2 ].x, _uvs[ uv2 ].y, _uvs[ uv3 ].x, _uvs[ uv3 ].y, material.map );

}

} else if ( material.envMap !== null ) {

if ( material.envMap.mapping === THREE.SphericalReflectionMapping ) {

_normal.copy( element.vertexNormalsModel[ uv1 ] ).applyMatrix3( _normalViewMatrix );

_uv1x = 0.5 * _normal.x + 0.5;

_uv1y = 0.5 * _normal.y + 0.5;

_normal.copy( element.vertexNormalsModel[ uv2 ] ).applyMatrix3( _normalViewMatrix );

_uv2x = 0.5 * _normal.x + 0.5;

_uv2y = 0.5 * _normal.y + 0.5;

_normal.copy( element.vertexNormalsModel[ uv3 ] ).applyMatrix3( _normalViewMatrix );

_uv3x = 0.5 * _normal.x + 0.5;

_uv3y = 0.5 * _normal.y + 0.5;

patternPath( _v1x, _v1y, _v2x, _v2y, _v3x, _v3y, _uv1x, _uv1y, _uv2x, _uv2y, _uv3x, _uv3y, material.envMap );

}

} else {

_color.copy( material.color );

if ( material.vertexColors === THREE.FaceColors ) {

_color.multiply( element.color );

}

material.wireframe === true

? strokePath( _color, material.wireframeLinewidth, material.wireframeLinecap, material.wireframeLinejoin )

: fillPath( _color );

}

} else if ( material instanceof THREE.MeshNormalMaterial ) {

_normal.copy( element.normalModel ).applyMatrix3( _normalViewMatrix );

_color.setRGB( _normal.x, _normal.y, _normal.z ).multiplyScalar( 0.5 ).addScalar( 0.5 );

material.wireframe === true

? strokePath( _color, material.wireframeLinewidth, material.wireframeLinecap, material.wireframeLinejoin )

: fillPath( _color );

} else {

_color.setRGB( 1, 1, 1 );

material.wireframe === true

? strokePath( _color, material.wireframeLinewidth, material.wireframeLinecap, material.wireframeLinejoin )

: fillPath( _color );

}

}

//

function drawTriangle( x0, y0, x1, y1, x2, y2 ) {

_context.beginPath();

_context.moveTo( x0, y0 );

_context.lineTo( x1, y1 );

_context.lineTo( x2, y2 );

_context.closePath();

}

function strokePath( color, linewidth, linecap, linejoin ) {

setLineWidth( linewidth );

setLineCap( linecap );

setLineJoin( linejoin );

setStrokeStyle( color.getStyle() );

_context.stroke();

_elemBox.expandByScalar( linewidth * 2 );

}

function fillPath( color ) {

setFillStyle( color.getStyle() );

_context.fill();

}

function textureToPattern( texture ) {

if ( texture.version === 0 ||

texture instanceof THREE.CompressedTexture ||

texture instanceof THREE.DataTexture ) {

return {

canvas: undefined,

version: texture.version

};

}

var image = texture.image;

if ( image.complete === false ) {

return {

canvas: undefined,

version: 0

};

}

var canvas = document.createElement( 'canvas' );

canvas.width = image.width;

canvas.height = image.height;

var context = canvas.getContext( '2d' );

context.setTransform( 1, 0, 0, - 1, 0, image.height );

context.drawImage( image, 0, 0 );

var repeatX = texture.wrapS === THREE.RepeatWrapping;

var repeatY = texture.wrapT === THREE.RepeatWrapping;

var repeat = 'no-repeat';

if ( repeatX === true && repeatY === true ) {

repeat = 'repeat';

} else if ( repeatX === true ) {

repeat = 'repeat-x';

} else if ( repeatY === true ) {

repeat = 'repeat-y';

}

var pattern = _context.createPattern( canvas, repeat );

if ( texture.onUpdate ) texture.onUpdate( texture );

return {

canvas: pattern,

version: texture.version

};

}

function patternPath( x0, y0, x1, y1, x2, y2, u0, v0, u1, v1, u2, v2, texture ) {

var pattern = _patterns[ texture.id ];

if ( pattern === undefined || pattern.version !== texture.version ) {

pattern = textureToPattern( texture );

_patterns[ texture.id ] = pattern;

}

if ( pattern.canvas !== undefined ) {

setFillStyle( pattern.canvas );

} else {

setFillStyle( 'rgba( 0, 0, 0, 1)' );

_context.fill();

return;

}

// http://extremelysatisfactorytotalitarianism.com/blog/?p=2120

var a, b, c, d, e, f, det, idet,

offsetX = texture.offset.x / texture.repeat.x,

offsetY = texture.offset.y / texture.repeat.y,

width = texture.image.width * texture.repeat.x,

height = texture.image.height * texture.repeat.y;

u0 = ( u0 + offsetX ) * width;

v0 = ( v0 + offsetY ) * height;

u1 = ( u1 + offsetX ) * width;

v1 = ( v1 + offsetY ) * height;

u2 = ( u2 + offsetX ) * width;

v2 = ( v2 + offsetY ) * height;

x1 -= x0; y1 -= y0;

x2 -= x0; y2 -= y0;

u1 -= u0; v1 -= v0;

u2 -= u0; v2 -= v0;

det = u1 * v2 - u2 * v1;

if ( det === 0 ) return;

idet = 1 / det;

a = ( v2 * x1 - v1 * x2 ) * idet;

b = ( v2 * y1 - v1 * y2 ) * idet;

c = ( u1 * x2 - u2 * x1 ) * idet;

d = ( u1 * y2 - u2 * y1 ) * idet;

e = x0 - a * u0 - c * v0;

f = y0 - b * u0 - d * v0;

_context.save();

_context.transform( a, b, c, d, e, f );

_context.fill();

_context.restore();

}

function clipImage( x0, y0, x1, y1, x2, y2, u0, v0, u1, v1, u2, v2, image ) {

// http://extremelysatisfactorytotalitarianism.com/blog/?p=2120

var a, b, c, d, e, f, det, idet,

width = image.width - 1,

height = image.height - 1;

u0 *= width; v0 *= height;

u1 *= width; v1 *= height;

u2 *= width; v2 *= height;

x1 -= x0; y1 -= y0;

x2 -= x0; y2 -= y0;

u1 -= u0; v1 -= v0;

u2 -= u0; v2 -= v0;

det = u1 * v2 - u2 * v1;

idet = 1 / det;

a = ( v2 * x1 - v1 * x2 ) * idet;

b = ( v2 * y1 - v1 * y2 ) * idet;

c = ( u1 * x2 - u2 * x1 ) * idet;

d = ( u1 * y2 - u2 * y1 ) * idet;

e = x0 - a * u0 - c * v0;

f = y0 - b * u0 - d * v0;

_context.save();

_context.transform( a, b, c, d, e, f );

_context.clip();

_context.drawImage( image, 0, 0 );

_context.restore();

}

// Hide anti-alias gaps

function expand( v1, v2, pixels ) {

var x = v2.x - v1.x, y = v2.y - v1.y,

det = x * x + y * y, idet;

if ( det === 0 ) return;

idet = pixels / Math.sqrt( det );

x *= idet; y *= idet;