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canvas-webgl.js
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"use strict";
(function() {
var EPSILON = 0.000001; //mostly used for zindex increments
var BEZIER_CURVE_RESOLUTION = 5; //space between interpolation points for quadratic and bezier curve approx. in pixels.
var ARC_RESOLUTION = 5; //space between interpolation points for quadratic and bezier curve approx. in pixels. Also used for linejoins and linecaps
var SQRT_2 = Math.sqrt(2);
var MAX_TEXTURE_SIZE = 4096;
var DEBUG = false; //depends on WebGLDebugUtils being imported previous to this
var CanvasRenderingContext2D = function(webgl_context) {
this.gl = webgl_context;
this._set_defaults()
var gl = this.gl;
this.currentZIndex = 0;
function create_program(vertex_shader_src, fragment_shader_src) {
var vertexShader = gl.createShader(gl.VERTEX_SHADER);
gl.shaderSource(vertexShader , vertex_shader_src);
gl.compileShader(vertexShader);
// Check the compile status
var compiled = gl.getShaderParameter(vertexShader, gl.COMPILE_STATUS);
if (!compiled) {
// Something went wrong during compilation; get the error
var lastError = gl.getShaderInfoLog(vertexShader);
console.log("*** Error compiling shader '" + vertexShader + "':" + lastError);
gl.deleteShader(vertexShader);
return null;
}
var fragmentShader = gl.createShader(gl.FRAGMENT_SHADER);
gl.shaderSource(fragmentShader, fragment_shader_src);
gl.compileShader(fragmentShader);
// Check the compile status
var compiled = gl.getShaderParameter(fragmentShader, gl.COMPILE_STATUS);
if (!compiled) {
// Something went wrong during compilation; get the error
var lastError = gl.getShaderInfoLog(fragmentShader);
console.log("*** Error compiling shader '" + fragmentShader + "':" + lastError);
gl.deleteShader(fragmentShader);
return null;
}
var program = gl.createProgram();
gl.attachShader(program, vertexShader);
gl.attachShader(program, fragmentShader);
gl.linkProgram(program);
return program;
}
//used for regular stroke/fill with no dash pattern and fixed color
this.simple_program = create_program(simple_draw_vertex_shader, simple_draw_fragment_shader);
//used for regular stroke/fill with no dash pattern and a texture the same size as the canvas for color
this.texture_program = create_program(texture_draw_vertex_shader, texture_draw_fragment_shader);
//used for regular stroke/fill with per-vertex color
this.gradient_program = create_program(gradient_vertex_shader, gradient_fragment_shader)
//used for regular stroke/fill with no dash pattern but per-vertex color
this.circle_program = create_program(simple_draw_vertex_shader, circle_gradient_fragment_shader)
//used for loading images
this.image_program = create_program(image_draw_vertex_shader2, image_draw_fragment_shader2);
//applies guassian blur
this.shadow_program = create_program(shadow_vertex_shader, shadow_fragment_shader);
//Accepts texture and location positions and maps them
this.direct_texture_program = create_program(direct_texture_draw_vertex_shader, texture_draw_fragment_shader);
this.projectionMatrix = [ //flips y, shift scale from [width, height] to [-1, 1]
2/gl.canvas.width, 0, 0, 0,
0, -2/gl.canvas.height, 0, 0,
0, 0, 2, 0,
-1, 1, 0, 1
];
//init image program
var program = this.image_program;
gl.useProgram(this.image_program);
program.transformLocation = gl.getUniformLocation(program, "u_matrix");
gl.uniformMatrix4fv(program.transformLocation, false, this.projectionMatrix);
program.textureLocation = gl.getUniformLocation(program, "texture");
program.zindexLocation = gl.getUniformLocation(program, "u_zindex");
program.globalAlphaLocation = gl.getUniformLocation(program, "u_global_alpha");
gl.uniform1f(program.globalAlphaLocation, this.globalAlpha);
program.positionLocation = gl.getAttribLocation(program, "a_position");
program.vertexBuffer = gl.createBuffer();
program.indexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, program.vertexBuffer);
gl.enableVertexAttribArray(program.positionLocation);
gl.vertexAttribPointer(program.positionLocation, 2, gl.FLOAT, false, 0, 0);
program.texCoordLocation = gl.getAttribLocation(program, "a_texcoord");
program.texCoordBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, program.texCoordBuffer);
gl.enableVertexAttribArray(program.texCoordLocation);
gl.vertexAttribPointer(program.texCoordLocation, 2, gl.FLOAT, false, 0, 0);
//init gradient draw program
program = this.gradient_program;
gl.useProgram(this.gradient_program);
program.zindexLocation = gl.getUniformLocation(program, "u_zindex");
program.globalAlphaLocation = gl.getUniformLocation(program, "u_global_alpha");
gl.uniform1f(program.globalAlphaLocation, this.globalAlpha);
program.transformLocation = gl.getUniformLocation(program, "u_matrix");
gl.uniformMatrix4fv(program.transformLocation, false, this.projectionMatrix);
program.positionLocation = gl.getAttribLocation(program, "a_position");
program.vertexBuffer = gl.createBuffer();
program.indexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, program.vertexBuffer);
gl.enableVertexAttribArray(program.positionLocation);
gl.vertexAttribPointer(program.positionLocation, 2, gl.FLOAT, false, 0, 0);
program.colorLocation = gl.getAttribLocation(program, "a_color");
program.colorBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, program.colorBuffer);
gl.enableVertexAttribArray(program.colorLocation);
gl.vertexAttribPointer(program.colorLocation, 4, gl.FLOAT, false, 0, 0);
//init simple draw program
program = this.simple_program;
gl.useProgram(this.simple_program);
program.colorLocation = gl.getUniformLocation(program, "u_color");
gl.uniform4f(program.colorLocation, 0, 0, 0, 1);
program.zindexLocation = gl.getUniformLocation(program, "u_zindex");
program.globalAlphaLocation = gl.getUniformLocation(program, "u_global_alpha");
gl.uniform1f(program.globalAlphaLocation, this.globalAlpha);
program.transformLocation = gl.getUniformLocation(program, "u_matrix");
gl.uniformMatrix4fv(program.transformLocation, false, this.projectionMatrix);
program.positionLocation = gl.getAttribLocation(program, "a_position");
program.vertexBuffer = gl.createBuffer();
program.indexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, program.vertexBuffer);
gl.enableVertexAttribArray(program.positionLocation);
gl.vertexAttribPointer(program.positionLocation, 2, gl.FLOAT, false, 0, 0);
//init circle gradient program
program = this.circle_program;
gl.useProgram(this.circle_program);
program.zindexLocation = gl.getUniformLocation(program, "u_zindex");
program.globalAlphaLocation = gl.getUniformLocation(program, "u_global_alpha");
gl.uniform1f(program.globalAlphaLocation, this.globalAlpha);
program.transformLocation = gl.getUniformLocation(program, "u_matrix");
gl.uniformMatrix4fv(program.transformLocation, false, this.projectionMatrix);
program.positionLocation = gl.getAttribLocation(program, "a_position");
program.vertexBuffer = gl.createBuffer();
program.indexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, program.vertexBuffer);
gl.enableVertexAttribArray(program.positionLocation);
gl.vertexAttribPointer(program.positionLocation, 2, gl.FLOAT, false, 0, 0);
program.circle1Location = gl.getUniformLocation(program, "circle1");
program.circle2Location = gl.getUniformLocation(program, "circle2");
program.color1Location = gl.getUniformLocation(program, "color1");
program.color2Location = gl.getUniformLocation(program, "color2");
//init texture draw program
program = this.texture_program;
gl.useProgram(this.texture_program);
program.zindexLocation = gl.getUniformLocation(program, "u_zindex");
program.globalAlphaLocation = gl.getUniformLocation(program, "u_global_alpha");
gl.uniform1f(program.globalAlphaLocation, this.globalAlpha);
program.transformLocation = gl.getUniformLocation(program, "u_matrix");
gl.uniformMatrix4fv(program.transformLocation, false, this.projectionMatrix);
program.textureLocation = gl.getUniformLocation(program, "texture");
program.positionLocation = gl.getAttribLocation(program, "a_position");
program.vertexBuffer = gl.createBuffer();
program.indexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, program.vertexBuffer);
gl.enableVertexAttribArray(program.positionLocation);
gl.vertexAttribPointer(program.positionLocation, 2, gl.FLOAT, false, 0, 0);
//init direct texture draw program
program = this.direct_texture_program;
gl.useProgram(this.direct_texture_program);
program.zindexLocation = gl.getUniformLocation(program, "u_zindex");
program.globalAlphaLocation = gl.getUniformLocation(program, "u_global_alpha");
gl.uniform1f(program.globalAlphaLocation, this.globalAlpha);
program.transformLocation = gl.getUniformLocation(program, "u_matrix");
gl.uniformMatrix4fv(program.transformLocation, false, this.projectionMatrix);
program.textureLocation = gl.getUniformLocation(program, "texture");
program.textureCoordsLocation = gl.getAttribLocation(program, "a_texcoord");
program.textureCoordsBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, program.textureCoordsBuffer);
gl.enableVertexAttribArray(program.textureCoordsLocation);
gl.vertexAttribPointer(program.textureCoordsLocation, 2, gl.FLOAT, false, 0, 0);
program.positionLocation = gl.getAttribLocation(program, "a_position");
program.vertexBuffer = gl.createBuffer();
program.indexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, program.vertexBuffer);
gl.enableVertexAttribArray(program.positionLocation);
gl.vertexAttribPointer(program.positionLocation, 2, gl.FLOAT, false, 0, 0);
//init shadow program
program = this.shadow_program;
gl.useProgram(this.shadow_program);
program.textureLocation = gl.getUniformLocation(program, "texture");
program.directionLocation = gl.getUniformLocation(program, "u_direction");
program.gaussCoeffLocation = gl.getUniformLocation(program, "u_gauss_coeff");
program.shadowColorLocation = gl.getUniformLocation(program, "u_shadow_color");
program.zindexLocation = gl.getUniformLocation(program, "u_zindex");
program.globalAlphaLocation = gl.getUniformLocation(program, "u_global_alpha");
gl.uniform1f(program.globalAlphaLocation, this.globalAlpha);
program.offsetLocation = gl.getUniformLocation(program, "u_offset");
program.positionLocation = gl.getAttribLocation(program, "a_position");
program.vertexBuffer = gl.createBuffer();
program.indexBuffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, program.vertexBuffer);
gl.enableVertexAttribArray(program.positionLocation);
gl.vertexAttribPointer(program.positionLocation, 2, gl.FLOAT, false, 0, 0);
//init some other random webgl stuff
gl.enable(gl.DEPTH_TEST);
gl.depthFunc(gl.LESS);
gl.blendFuncSeparate(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA, gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
gl.enable(gl.BLEND);
//TODO: this doesn't look pretty, does it
var _this = this;
var widthProp = Object.getOwnPropertyDescriptor(gl.canvas.__proto__, 'width');
var heightProp = Object.getOwnPropertyDescriptor(gl.canvas.__proto__, 'height');
Object.defineProperty(gl.canvas, "width", {
set: function myProperty(new_width) {
widthProp.set.call(gl.canvas, new_width);
_this._resize();
},
get: function() {
return widthProp.get.call(gl.canvas);
}
});
Object.defineProperty(gl.canvas, "height", {
set: function myProperty(new_height) {
heightProp.set.call(gl.canvas, new_height);
_this._resize();
},
get: function() {
return heightProp.get.call(gl.canvas);
}
});
}
CanvasRenderingContext2D.prototype = {
_set_defaults() {
this.globalAlpha = 1;
this.globalCompositeOperation = "source-over";
this.strokeStyle = "#000";
this.strokeStyleRGBA = [0,0,0,1];
this.fillStyle = "#000";
this.fillStyleRGBA = [0,0,0,1];
this.shadowColor = "rgba(0, 0, 0, 0.0)";
this.shadowColorRGBA = [0,0,0,0];
this.shadowOffsetX = 0;
this.shadowOffsetY = 0;
this.shadowBlur = 0;
this.lineWidth = 1.0;
this.lineWidthSupported = true;
this.font = "10px sans-serif";
this.lineJoin = "miter";
this.miterLimit = 10;
this.textAlign = "start";
this.lineCap = 'butt'
this.lineDash = [];
this.lineDashOffset = 0;
this.textBaseline = 'alphabetic';
this.direction = 'inherit';
this.path = new Path2D();
this._transform = [1, 0, 0, 0,
0, 1, 0, 0,
0, 0, 1, 0,
0, 0, 0, 1];
this._savedWidth = this.width;
this._savedHeight = this.height;
},
setTransform(a, b, c, d, e, f) {
this._transform = [a,b,0,0,
c,d,0,0,
0,0,1,0,
e,f,0,1];
},
rotate(angle) {
var rotation = [Math.cos(angle), Math.sin(angle), 0, 0,
-Math.sin(angle), Math.cos(angle), 0, 0,
0,0,1,0,
0,0,0,1];
this._transform = matrixMultiply(rotation, this._transform);
},
scale(x, y) {
var scale = [x, 0, 0, 0,
0, y, 0, 0,
0, 0, 1, 0,
0, 0, 0, 1];
this._transform = matrixMultiply(scale, this._transform);
},
translate(x, y) {
var translate = [1, 0, 0, 0,
0, 1, 0, 0,
0, 0, 1, 0,
x, y, 0, 1];
this._transform = matrixMultiply(translate, this._transform);
},
transform(a, b, c, d, e, f) {
var transform = [a, b, 0, 0,
c, d, 0, 0,
0, 0, 1, 0,
e, f, 0, 1];
this._transform = matrixMultiply(transform, this._transform);
},
resetTransform() {
this._transform = [1, 0, 0, 0,
0, 1, 0, 0,
0, 0, 1, 0,
0, 0, 0, 1];
},
set currentTransform(matrix) {
this._transform = [matrix.a, matrix.b, 0, 0,
matrix.c, matrix.d, 0, 0,
0, 0, 1, 0,
matrix.e, matrix.f, 0, 1];
},
get currentTransform() {
return new SVGMatrix(this._transform[0], this._transform[1], this._transform[4],
this._transform[5], this._transform[12], this._transform[13]);
},
save() {
var saveState = {_transform:this._transform, clipPlane:this.clipPlane, strokeStyleRGBA:this.strokeStyleRGBA, fillStyleRGBA:this.fillStyleRGBA, _strokeStyle:this._strokeStyle, _fillStyle:this._fillStyle, globalAlpha:this.globalAlpha, lineWidth:this.lineWidth,
lineCap:this.lineCap, lineJoin:this.lineJoin, miterLimit:this.miterLimit,lineDashOffset:this.lineDashOffset, shadowOffsetX:this.shadowOffsetX,
shadowOffsetY:this.shadowOffsetY, shadowBlur:this.shadowBlur, _shadowColorRGBA:this._shadowColorRGBA, _shadowColor:this._shadowColor, filter:this.filter, globalCompositeOperation:this.globalCompositeOperation,
font:this.font, textAlign:this.textAlign, textBaseline:this.textBaseline, direction:this.direction, imageSmoothingEnabled:this.imageSmoothingEnabled,
imageSmoothingQuality:this.imageSmoothingQuality, lineDash:this.lineDash};
if (this.saveStack) {
this.saveStack.push(saveState);
} else {
this.saveStack = [saveState];
}
},
restore() {
if (this.saveStack && this.saveStack.length > 0) {
var s = this.saveStack.pop();
this._transform = s._transform;
this.clipPlane = s.clipPlane;
this.strokeStyleRGBA = s.strokeStyleRGBA;
this.fillStyleRGBA = s.fillStyleRGBA;
this._strokeStyle = s._strokeStyle;
this._fillStyle = s._fillStyle;
this.globalAlpha = s.globalAlpha;
this.lineWidth = s.lineWidth;
this.lineCap = s.lineCap;
this.lineJoin = s.lineJoin;
this.miterLimit = s.miterLimit;
this.lineDashOffset = s.lineDashOffset;
this.shadowOffsetX = s.shadowOffsetX;
this.shadowOffsetY = s.shadowOffsetY;
this._shadowColor = s._shadowColor;
this._shadowColorRGBA = s._shadowColorRGBA;
this.shadowBlur = s.shadowBlur;
this.filter = s.filter;
this.globalCompositeOperation = s.globalCompositeOperation;
this.font = s.font;
this.textAlign = s.textAlign;
this.textBaseline = s.textBaseline;
this.direction = s.direction;
this.imageSmoothingEnabled = s.imageSmoothingEnabled;
this.imageSmoothingQuality = s.imageSmoothingQuality;
this.lineDash = s.lineDash;
}
},
getImageData(sx, sy, sw, sh) {
var gl = this.gl;
var data = this.createImageData(sw, sh)
var buffer = new Uint8Array(sw * sh * 4);
gl.readPixels(sx, this.height-sh-sy, sw, sh, gl.RGBA, gl.UNSIGNED_BYTE, buffer);
//reverse rows
for (var i = 0; i < sh; i++) {
for (var j = 0; j < sw; j++) {
data.data[(i*sw + j)*4] = buffer[((sh-i-1)*sw + j)*4];
data.data[(i*sw + j)*4+1] = buffer[((sh-i-1)*sw + j)*4+1];
data.data[(i*sw + j)*4+2] = buffer[((sh-i-1)*sw + j)*4+2];
data.data[(i*sw + j)*4+3] = buffer[((sh-i-1)*sw + j)*4+3];
}
}
return data;
},
putImageData(imagedata, dx, dy, x, y, w, h) {
var gl = this.gl;
x = (x === undefined) ? 0 : x;
y = (y === undefined) ? 0 : y;
w = (w === undefined) ? imagedata.width : w;
h = (h === undefined) ? imagedata.height : h;
var iw = imagedata.width, ih = imagedata.height;
var buffer;
if (w != iw || h != ih) {
//extract points
buffer = new Uint8Array(w * h * 4);
for (var i = 0; i < h; i++) {
for (var j = 0; j < w; j++) {
buffer[(i*w + j)*4] = imagedata.data[((i+y)*iw + x + j)*4];
buffer[(i*w + j)*4+1] = imagedata.data[((i+y)*iw + x + j)*4+1];
buffer[(i*w + j)*4+2] = imagedata.data[((i+y)*iw + x + j)*4+2];
buffer[(i*w + j)*4+3] = imagedata.data[((i+y)*iw + x + j)*4+3];
}
}
} else {
//we can just use it directly
if (!(imagedata.data instanceof Uint8Array)) {
buffer = new Uint8Array(imagedata.data);
} else {
buffer = imagedata.data;
}
}
var program = this._select_program(this.direct_texture_program);
var texture = gl.createTexture();
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, w, h, 0, gl.RGBA, gl.UNSIGNED_BYTE, buffer);
gl.uniform1i(program.textureLocation, 0);
var transform = matrixMultiply(this._transform, this.projectionMatrix);
gl.uniformMatrix4fv(program.transformLocation, false, transform);
gl.uniform1f(program.globalAlphaLocation, this.globalAlpha);
this._set_zindex();
this.__prepare_clip();
gl.bindBuffer(gl.ARRAY_BUFFER, program.textureCoordsBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([0,0,1,0,1,1,0,1]), gl.STATIC_DRAW);
gl.vertexAttribPointer(program.textureCoordsLocation, 2, gl.FLOAT, false, 0, 0);
gl.bindBuffer(gl.ARRAY_BUFFER, program.vertexBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([dx+x, dy+y, dx+x+w, dy+y, dx+x+w, dy+y+h, dx+x, dy+y+h]), gl.STATIC_DRAW);
gl.vertexAttribPointer(program.positionLocation, 2, gl.FLOAT, false, 0, 0);
gl.drawArrays(gl.TRIANGLE_FAN, 0, 4);
this.__execute_clip(this.currentZIndex)
this.currentZIndex -=EPSILON;
},
createImageData(width, height) {
if (height === undefined) {
height = this.height;
width = this.width;
}
var data = new ImageData();
data.data = new Uint8ClampedArray(width * height * 4);
data.width = width;
data.height = height;
return data;
},
_set_zindex() {
var gl = this.gl;
this.currentZIndex-=EPSILON;
var program = gl.getParameter(gl.CURRENT_PROGRAM);
gl.uniform1f(program.zindexLocation, this.currentZIndex);
},
beginPath() {
this.path = new Path2D();
},
closePath() {
this.path.closePath();
},
moveTo(x,y) {
this.path.moveTo(x,y);
},
lineTo(x,y) {
this.path.lineTo(x,y);
},
bezierCurveTo(cp1x, cp1y, cp2x, cp2y, x, y) {
this.path.bezierCurveTo(cp1x, cp1y, cp2x, cp2y, x, y);
},
quadraticCurveTo(cpx, cpy, x, y) {
this.path.quadraticCurveTo(cpx, cpy, x, y);
},
arc(x, y, radius, startAngle, endAngle, anticlockwise) {
this.path.arc(x, y, radius, startAngle, endAngle, anticlockwise);
},
ellipse(x, y, radiusX, radiusY, rotation, startAngle, endAngle, anticlockwise) {
this.path.ellipse(x, y, radiusX, radiusY, rotation, startAngle, endAngle, anticlockwise);
},
arcTo(x1, y1, x2, y2, radiusX, radiusY, rotation) {
this.path.arcTo(x1, y1, x2, y2, radiusX, radiusY, rotation);
},
rect(x, y, width, height) {
this.path.rect(x, y, width, height);
},
stroke(path) {
var _path = this.path;
if(path) {
_path = path;
}
var gl = this.gl;
if (!this.textureManager) {
this.textureManager = new TextureManager(gl, MAX_TEXTURE_SIZE, MAX_TEXTURE_SIZE);
}
var tex_offsets;
var flat_color = true;
if (this.strokeStyleRGBA instanceof WebGLTexture) {
this.strokeStyleRGBA.width = this.width;
this.strokeStyleRGBA.height = this.height;
this.textureManager.set_texture_from_texture(this.strokeStyleRGBA, this);
flat_color = false;
tex_offsets = [this.strokeStyleRGBA.nodes[0].rect.x, this.strokeStyleRGBA.nodes[0].rect.y];
} else {
tex_offsets = this.textureManager.set_color(this.strokeStyleRGBA);
}
if (!_path.stroke_lineWidth || _path.stroke_lineWidth != this.lineWidth) {
//buffer is only correct for a certain linewidth
_path.stroke_buffered = 0;
_path.stroke_lineWidth = this.lineWidth;
_path.stroke_texPoints = new TypedArray(Float32Array);
_path.stroke_vertices = new TypedArray(Float32Array);
_path.stroke_indices = new TypedArray(Uint16Array);
}
for (;_path.stroke_buffered < _path.paths.length; _path.stroke_buffered++) {
var i = _path.stroke_buffered;
var currentPath = _path.paths[i];
if (currentPath.length > 2) {
this.__strokePath(currentPath, _path.closed[i], _path.stroke_vertices, _path.stroke_indices);
if (flat_color) {
for (var j = _path.stroke_texPoints.length; j < _path.stroke_vertices.length; j+=2) {
_path.stroke_texPoints.push((tex_offsets[0]+0.5)/MAX_TEXTURE_SIZE, (tex_offsets[1]+0.5)/MAX_TEXTURE_SIZE);
}
} else {
for (var j = _path.stroke_texPoints.length; j < _path.stroke_vertices.length; j+=2) {
_path.stroke_texPoints.push((tex_offsets[0]+_path.stroke_vertices.b[j])/MAX_TEXTURE_SIZE,
(tex_offsets[1]+this.height-_path.stroke_vertices.b[j+1])/MAX_TEXTURE_SIZE);
}
}
}
}
this.__draw(_path.stroke_vertices, _path.stroke_indices, _path.stroke_texPoints);
},
clip(path) {
var _path = this.path;
if(path) {
_path = path;
}
if (!this.clipPlane) {
this.clipPlane = [];
}
for (var i in _path.paths) {
var currentPath = _path.paths[i];
var transformedPath = [];
for (var j = 0; j < currentPath.length; j+=2) {
var tranformed = vectTransform(this._transform, [currentPath[j], currentPath[j+1]]);
transformedPath.push(tranformed[0], tranformed[1])
}
var closed = transformedPath[0] == transformedPath[transformedPath.length-2] && transformedPath[1] == transformedPath[transformedPath.length-1];
if (!closed) {
transformedPath.push(transformedPath[0], transformedPath[1]);
}
var triangles = earcut(transformedPath);
for (var i = 0; i < triangles.length; i+=3) {
this.clipPlane.push(transformedPath[triangles[i]*2], transformedPath[triangles[i]*2+1]);
this.clipPlane.push(transformedPath[triangles[i+1]*2], transformedPath[triangles[i+1]*2+1]);
this.clipPlane.push(transformedPath[triangles[i+2]*2], transformedPath[triangles[i+2]*2+1]);
}
}
},
resetClip() {
delete this.clipPlane;
delete this.clipFramebuffer;
delete this.clipTexture
},
__prepare_clip() {
if (this.clipPlane) {
var gl = this.gl;
gl.activeTexture(gl.TEXTURE5);
if (!this.clipFramebuffer) {
gl.activeTexture(gl.TEXTURE5);
this.clipFramebuffer = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, this.clipFramebuffer);
this.clipFramebuffer.width = this.width;
this.clipFramebuffer.height = this.height;
this.clipTexture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, this.clipTexture);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, this.clipFramebuffer.width, this.clipFramebuffer.height, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, this.clipTexture, 0);
gl.clearColor(0, 0, 0, 0);
} else {
gl.activeTexture(gl.TEXTURE5);
gl.bindFramebuffer(gl.FRAMEBUFFER, this.clipFramebuffer);
gl.bindTexture(gl.TEXTURE_2D, this.clipTexture);
gl.clear(gl.COLOR_BUFFER_BIT);
}
}
},
__execute_clip(z_index) {
var gl = this.gl;
if (this.clipPlane && this.clipPlane.length > 0 ) {
var program = this._select_program(this.texture_program);
gl.bindFramebuffer(gl.FRAMEBUFFER, null);
gl.activeTexture(gl.TEXTURE5);
gl.bindTexture(gl.TEXTURE_2D, this.clipTexture);
gl.uniform1i(program.textureLocation, 5);
gl.uniformMatrix4fv(program.transformLocation, false, this.projectionMatrix);
gl.vertexAttribPointer(program.positionLocation, 2, gl.FLOAT, false, 0, 0);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(this.clipPlane), gl.STATIC_DRAW);
gl.uniform1f(program.zindexLocation, z_index);
gl.drawArrays(gl.TRIANGLES, 0, this.clipPlane.length/2);
}
gl.bindTexture(gl.TEXTURE_2D, null);
},
isPointInPath(path, x, y) {
//works but I wouldn't recommend using it a whole lot, cause it's sloooow
//It triangulates and then checks every triangle
var _path, _x, _y;
if(path && path instanceof Path2D) {
_path = path;
_x = x;
_y = y;
} else {
_path = this.path;
_x = path;
_y = x;
}
for (var k in _path.paths) {
var currentPath = _path.paths[k];
var closed = currentPath[0] == currentPath[currentPath.length-2] && currentPath[1] == currentPath[currentPath.length-1];
if (!closed) {
currentPath.push(currentPath[0], currentPath[1]);
}
var triangles = earcut(currentPath);
for (var i = 0; i < triangles.length; i+=3) {
if (is_in_triangle(_x, _y, currentPath[triangles[i]*2],currentPath[triangles[i]*2+1],
currentPath[triangles[i+1]*2],currentPath[triangles[i+1]*2+1],
currentPath[triangles[i+2]*2],currentPath[triangles[i+2]*2+1])) return true;
}
if (!closed) {
currentPath.pop();
currentPath.pop();
}
}
return false;
},
isPointInStroke(path, x, y) {
//works but I wouldn't recommend using it a whole lot, cause it's sloooow
var _path, _x, _y;
if(path && path instanceof Path2D) {
_path = path;
_x = x;
_y = y;
} else {
_path = this.path;
_x = path;
_y = x;
}
var lineWidthDiv2 = this.lineWidth / 2.0;
for (var k in _path.paths) {
var currentPath = _path.paths[k];
var vertices = new TypedArray(Float32Array);
var indices = new TypedArray(Uint16Array);
this.__strokePath(currentPath, _path.closed[k], vertices, indices);
for (var i = 0; i < indices.length; i+=3) {
if (is_in_triangle(_x, _y, vertices.b[indices.b[i]*2], vertices.b[indices.b[i]*2+1],
vertices.b[indices.b[i+1]*2], vertices.b[indices.b[i+1]*2+1],
vertices.b[indices.b[i+2]*2], vertices.b[indices.b[i+2]*2+1])) { return true; }
}
}
return false;
},
get canvas() { return this.gl.canvas; },
get height() { return this.canvas.height; },
get width() { return this.canvas.width; },
_resize() {
var gl = this.gl;
gl.clear(gl.COLOR_BUFFER_BIT);
this.resetTransform();
this.path = new Path2D();
//delete some buffers we may have lying around
delete this.clipFramebuffer;
delete this.clipTexture;
delete this.clipPlane;
delete this.shadowFramebuffer;
delete this.shadowFramebuffer2;
delete this.shadowTexture;
delete this.shadowTexture2;
delete this.imageTexture;
delete this.cachedImage;
delete this.textRenderCanvas;
delete this.TextureManager;
},
createLinearGradient(x0, y0, x1, y1) {
return new LinearGradient(x0, y0, x1, y1);
},
createRadialGradient(x0, y0, r0, x1, y1, r1) {
return new RadialGradient(x0, y0, r0, x1, y1, r1);
},
createPattern(image, repetition) {
return new CanvasPattern(image, repetition);
},
getLineDash() {
return this.lineDash;
},
setLineDash(new_line_dash) {
if (this.lineDash.length % 2 == 1) {
this.lineDash = new_line_dash.concat(new_line_dash);
} else {
this.lineDash = new_line_dash;
}
},
_prepare_line_dash(path, closed, lineWidthDiv2) {
if (closed) {
path.push(path[0], path[1]);
}
var currentOffset = this.lineDashOffset;
var dash_index = 0;
var draw = 1;
while (currentOffset > this.lineDash[dash_index]) {
currentOffset -= this.lineDash[dash_index];
dash_index++;
if (draw) draw = 0; else draw = 1;
if (dash_index == this.lineDash.length) {
dash_index = 0;
}
}
var new_path = [path[0], path[1]];
var to_draw_or_not_to_draw = [draw];
var skipped_dash_switch = false;
for (var i = 2; i < path.length; i+=2) {
var line = [path[i]-path[i-2], path[i+1]-path[i-1]];
var line_l = Math.sqrt(Math.pow(line[0], 2) + Math.pow(line[1], 2))
line[0] /= line_l; line[1] /= line_l;
var progress = 0;
while (line_l - progress + currentOffset >= this.lineDash[dash_index]) {
progress += this.lineDash[dash_index] - currentOffset;
currentOffset = 0;
if (draw) draw = 0; else draw = 1;
dash_index++;
if (dash_index == this.lineDash.length) {
dash_index = 0;
}
to_draw_or_not_to_draw.push(draw);
new_path.push(path[i-2] + progress * line[0], path[i-1] + progress * line[1]);
}
if (line_l - progress != 0) {
new_path.push(path[i], path[i+1])
to_draw_or_not_to_draw.push(draw);
}
currentOffset += line_l - progress;
}
//I've once wished this was available so I could continue a dash pattern with a different stroked path, so now it is
this.currentLineDashOffset = currentOffset;
for (var i = 0; i < dash_index; i++) {
this.currentLineDashOffset += this.lineDash[dash_index];
}
if (closed) {
path.pop();
path.pop();
new_path.pop();
new_path.pop();
to_draw_or_not_to_draw.pop();
}
return [new_path, to_draw_or_not_to_draw];
},
set globalCompositeOperation(new_globcomp) {
var gl = this.gl;
switch(new_globcomp) {
case 'source-over':
gl.blendEquation(gl.FUNC_ADD);
gl.blendFuncSeparate(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA, gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
break;
case 'copy':
gl.blendEquation(gl.FUNC_ADD);
gl.blendFunc(gl.ONE, gl.ZERO);
break;
case 'lighter': //works
gl.blendEquation(gl.FUNC_ADD);
gl.blendFuncSeparate(gl.ONE, gl.ONE, gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
break;
default:
return; //couldn't find it, so don't change it
}
this._globalCompositeOperation = new_globcomp;
},
get globalCompositeOperation() {
return this._globalCompositeOperation;
},
get fillStyle() {
return this._fillStyle;
},
set fillStyle(new_color) {
if (new_color == this._fillStyle) return;
this._fillStyle = new_color;
if (typeof new_color == 'string') {
this.fillStyleRGBA = parseColor(new_color);
} else {
this.fillStyleRGBA = new_color._generateTexture(this, this.width, this.height);
}
},
get strokeStyle() {
return this._strokeStyle;
},
set strokeStyle(new_color) {
if (new_color == this._strokeStyle) return;
this._strokeStyle = new_color;
if (typeof new_color == 'string') {
this.strokeStyleRGBA = parseColor(new_color);
} else {
this.strokeStyleRGBA = new_color._generateTexture(this, this.width, this.height);
}
},
get shadowColor() {
return this._shadowColor;
},
set shadowColor(new_color) {
if (new_color == this._shadowColor) return;
this._shadowColor = new_color;
if (typeof new_color == 'string') {
this._shadowColorRGBA = parseColor(new_color);
}
},
_select_program(program) {
if (this.gl.getParameter(this.gl.CURRENT_PROGRAM) != program) {
this.gl.useProgram(program);
}
return program;
},
_draw_shadow(transform, z_index, draw_cb) {
if (this.shadowOffsetX == 0 && this.shadowOffsetY==0 && this.shadowBlur == 0) return;
var gl = this.gl;
var old_texture = gl.getParameter(gl.ACTIVE_TEXTURE);
var old_texture_binding = gl.getParameter(gl.TEXTURE_BINDING_2D);
var old_framebuffer_binding = gl.getParameter(gl.FRAMEBUFFER_BINDING);
var old_program = gl.getParameter(gl.CURRENT_PROGRAM);
var old_renderbuffer = gl.getParameter(gl.RENDERBUFFER_BINDING);
if (!this.shadowTexture) {
this.shadowFramebuffer2 = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, this.shadowFramebuffer2);
this.shadowFramebuffer2.width = this.width;
this.shadowFramebuffer2.height = this.height;
gl.activeTexture(gl.TEXTURE1);
this.shadowTexture2 = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, this.shadowTexture2);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, this.shadowFramebuffer2.width, this.shadowFramebuffer2.height, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, this.shadowTexture2, 0);
gl.clearColor(0, 0, 0, 0);
this.shadowFramebuffer = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, this.shadowFramebuffer);
this.shadowFramebuffer.width = this.width;
this.shadowFramebuffer.height = this.height;
gl.activeTexture(gl.TEXTURE0);
this.shadowTexture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, this.shadowTexture);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, this.shadowFramebuffer.width, this.shadowFramebuffer.height, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, this.shadowTexture, 0);
gl.clearColor(0, 0, 0, 0);
} else {
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, this.shadowTexture);
gl.bindFramebuffer(gl.FRAMEBUFFER, this.shadowFramebuffer2);
gl.clear(gl.COLOR_BUFFER_BIT);
gl.bindFramebuffer(gl.FRAMEBUFFER, this.shadowFramebuffer);
gl.clear(gl.COLOR_BUFFER_BIT);
}
var program = gl.getParameter(gl.CURRENT_PROGRAM);
var projection_and_move_offset = [ //flips y, shift scale from [width, height] to [-1, 1]
2/gl.canvas.width, 0, 0, 0,
0, -2/gl.canvas.height, 0, 0,
0, 0, 1, 0,
-1+2*this.shadowOffsetX/gl.canvas.width, 1-2*this.shadowOffsetY/gl.canvas.height, 0, 1
];
var new_transform = matrixMultiply(transform, projection_and_move_offset)
gl.uniformMatrix4fv(program.transformLocation, false, new_transform);
draw_cb(); //draw the thing we're shadowing into the texture
gl.uniformMatrix4fv(program.transformLocation, false, this.projectionMatrix);
var program = this._select_program(this.shadow_program);
//this piece of code is to calculate coefficients for the gaussian blur
//gaussian error function from http://picomath.org/javascript/erf.js.html
function erf(x) {
// constants
var a1 = 0.254829592;
var a2 = -0.284496736;
var a3 = 1.421413741;
var a4 = -1.453152027;
var a5 = 1.061405429;
var p = 0.3275911;
// Save the sign of x
var sign = 1;
if (x < 0)
sign = -1;
x = Math.abs(x);
// A&S formula 7.1.26
var t = 1.0/(1.0 + p*x);
var y = 1.0 - (((((a5*t + a4)*t) + a3)*t + a2)*t + a1)*t*Math.exp(-x*x);
return sign*y;
}
//definite integral of the gaussian function from -inf to x
function def_int_gaussian(x, mu, sigma) {
return 0.5 * erf((x-mu)/(SQRT_2 * sigma));
}
var sigma = this.shadowBlur/2;
//Guassian function is a continuous function. So theoretically all pixels contribute to the value of every
//other pixel. In reality it drops off fast. We only consider pixels 3 * sigma away, because they will
//contribute 99.7% of the real value, which is good enough. The +0.5 is to make the number of coeff always odd.
var kernel_size = 3 * Math.ceil(sigma) + 0.5;
var start_x = -kernel_size;
var end_x = kernel_size;
var coeff = []
var last_int = def_int_gaussian(start_x, 0, sigma);
for (var xi = start_x; xi < end_x; xi+=1) {
var new_int = def_int_gaussian(xi+1, 0, sigma)
coeff.push(new_int-last_int);
last_int = new_int;
}
//renormalize
var sum = 0;
for (var i in coeff) {
sum += coeff[i]
}
for (var i in coeff) {
coeff[i] /= sum;
}