Files
konva/src/shapes/Path.js
2012-06-06 00:33:29 -04:00

370 lines
14 KiB
JavaScript

///////////////////////////////////////////////////////////////////////
// SVG Path
///////////////////////////////////////////////////////////////////////
/**
* Path constructor. This shape was inspired by Jason Follas's
* SVG Path plugin. Jason also helped build the parser and the
* drawing function.
* @constructor
* @augments Kinetic.Shape
* @param {Object} config
*/
Kinetic.Path = function(config) {
this.shapeType = "Path";
this.dataArray = [];
config.drawFunc = function() {
var context = this.getContext();
var ca = this.dataArray;
// context position
context.beginPath();
for(var n = 0; n < ca.length; n++) {
var c = ca[n].command;
var p = ca[n].points;
switch(c) {
case 'L':
context.lineTo(p[0], p[1]);
break;
case 'M':
context.moveTo(p[0], p[1]);
break;
case 'C':
context.bezierCurveTo(p[0], p[1], p[2], p[3], p[4], p[5]);
break;
case 'Q':
context.quadraticCurveTo(p[0], p[1], p[2], p[3]);
break;
case 'A':
var cx = p[0], cy = p[1], rx = p[2], ry = p[3], theta = p[4], dTheta = p[5], psi = p[6], fs = p[7];
var r = (rx > ry) ? rx : ry;
var scaleX = (rx > ry) ? 1 : rx / ry;
var scaleY = (rx > ry) ? ry / rx : 1;
context.translate(cx, cy);
context.rotate(psi);
context.scale(scaleX, scaleY);
context.arc(0, 0, r, theta, theta + dTheta, 1 - fs);
context.scale(1 / scaleX, 1 / scaleY);
context.rotate(-psi);
context.translate(-cx, -cy);
break;
case 'z':
context.closePath();
break;
}
}
this.fill();
this.stroke();
};
// call super constructor
Kinetic.Shape.apply(this, [config]);
this.dataArray = this.getDataArray();
};
/*
* Path methods
*/
Kinetic.Path.prototype = {
/**
* get parsed data array from the data
* string. V, v, H, h, and l data are converted to
* L data for the purpose of high performance Path
* rendering
*/
getDataArray: function() {
// Path Data Segment must begin with a moveTo
//m (x y)+ Relative moveTo (subsequent points are treated as lineTo)
//M (x y)+ Absolute moveTo (subsequent points are treated as lineTo)
//l (x y)+ Relative lineTo
//L (x y)+ Absolute LineTo
//h (x)+ Relative horizontal lineTo
//H (x)+ Absolute horizontal lineTo
//v (y)+ Relative vertical lineTo
//V (y)+ Absolute vertical lineTo
//z (closepath)
//Z (closepath)
//c (x1 y1 x2 y2 x y)+ Relative Bezier curve
//C (x1 y1 x2 y2 x y)+ Absolute Bezier curve
//q (x1 y1 x y)+ Relative Quadratic Bezier
//Q (x1 y1 x y)+ Absolute Quadratic Bezier
//t (x y)+ Shorthand/Smooth Relative Quadratic Bezier
//T (x y)+ Shorthand/Smooth Absolute Quadratic Bezier
//s (x2 y2 x y)+ Shorthand/Smooth Relative Bezier curve
//S (x2 y2 x y)+ Shorthand/Smooth Absolute Bezier curve
//a (rx ry x-axis-rotation large-arc-flag sweep-flag x y)+ Relative Elliptical Arc
//A (rx ry x-axis-rotation large-arc-flag sweep-flag x y)+ Absolute Elliptical Arc
// command string
var cs = this.attrs.data;
// command chars
var cc = ['m', 'M', 'l', 'L', 'v', 'V', 'h', 'H', 'z', 'Z', 'c', 'C', 'q', 'Q', 't', 'T', 's', 'S', 'a', 'A'];
// convert white spaces to commas
cs = cs.replace(new RegExp(' ', 'g'), ',');
// create pipes so that we can split the data
for(var n = 0; n < cc.length; n++) {
cs = cs.replace(new RegExp(cc[n], 'g'), '|' + cc[n]);
}
// create array
var arr = cs.split('|');
var ca = [];
// init context point
var cpx = 0;
var cpy = 0;
for(var n = 1; n < arr.length; n++) {
var str = arr[n];
var c = str.charAt(0);
str = str.slice(1);
// remove ,- for consistency
str = str.replace(new RegExp(',-', 'g'), '-');
// add commas so that it's easy to split
str = str.replace(new RegExp('-', 'g'), ',-');
var p = str.split(',');
if(p.length > 0 && p[0] === '') {
p.shift();
}
// convert strings to floats
for(var i = 0; i < p.length; i++) {
p[i] = parseFloat(p[i]);
}
while(p.length > 0) {
if(isNaN(p[0]))// case for a trailing comma before next command
break;
var cmd = undefined;
var points = [];
// convert l, H, h, V, and v to L
switch(c) {
// Note: Keep the lineTo's above the moveTo's in this switch
case 'l':
cpx += p.shift();
cpy += p.shift();
cmd = 'L';
points.push(cpx, cpy);
break;
case 'L':
cpx = p.shift();
cpy = p.shift();
points.push(cpx, cpy);
break;
// Note: lineTo handlers need to be above this point
case 'm':
cpx += p.shift();
cpy += p.shift();
cmd = 'M';
points.push(cpx, cpy);
c = 'l';
// subsequent points are treated as relative lineTo
break;
case 'M':
cpx = p.shift();
cpy = p.shift();
cmd = 'M';
points.push(cpx, cpy);
c = 'L';
// subsequent points are treated as absolute lineTo
break;
case 'h':
cpx += p.shift();
cmd = 'L';
points.push(cpx, cpy);
break;
case 'H':
cpx = p.shift();
cmd = 'L';
points.push(cpx, cpy);
break;
case 'v':
cpy += p.shift();
cmd = 'L';
points.push(cpx, cpy);
break;
case 'V':
cpy = p.shift();
cmd = 'L';
points.push(cpx, cpy);
break;
case 'C':
points.push(p.shift(), p.shift(), p.shift(), p.shift());
cpx = p.shift();
cpy = p.shift();
points.push(cpx, cpy);
break;
case 'c':
points.push(cpx + p.shift(), cpy + p.shift(), cpx + p.shift(), cpy + p.shift());
cpx += p.shift();
cpy += p.shift();
cmd = 'C'
points.push(cpx, cpy);
break;
case 'S':
var ctlPtx = cpx, ctlPty = cpy;
var prevCmd = ca[ca.length - 1];
if(prevCmd.command === 'C') {
ctlPtx = cpx + (cpx - prevCmd.points[2]);
ctlPty = cpy + (cpy - prevCmd.points[3]);
}
points.push(ctlPtx, ctlPty, p.shift(), p.shift())
cpx = p.shift();
cpy = p.shift();
cmd = 'C';
points.push(cpx, cpy);
break;
case 's':
var ctlPtx = cpx, ctlPty = cpy;
var prevCmd = ca[ca.length - 1];
if(prevCmd.command === 'C') {
ctlPtx = cpx + (cpx - prevCmd.points[2]);
ctlPty = cpy + (cpy - prevCmd.points[3]);
}
points.push(ctlPtx, ctlPty, cpx + p.shift(), cpy + p.shift())
cpx += p.shift();
cpy += p.shift();
cmd = 'C';
points.push(cpx, cpy);
break;
case 'Q':
points.push(p.shift(), p.shift());
cpx = p.shift();
cpy = p.shift();
points.push(cpx, cpy);
break;
case 'q':
points.push(cpx + p.shift(), cpy + p.shift());
cpx += p.shift();
cpy += p.shift();
cmd = 'Q'
points.push(cpx, cpy);
break;
case 'T':
var ctlPtx = cpx, ctlPty = cpy;
var prevCmd = ca[ca.length - 1];
if(prevCmd.command === 'Q') {
ctlPtx = cpx + (cpx - prevCmd.points[0]);
ctlPty = cpy + (cpy - prevCmd.points[1]);
}
cpx = p.shift();
cpy = p.shift();
cmd = 'Q';
points.push(ctlPtx, ctlPty, cpx, cpy);
break;
case 't':
var ctlPtx = cpx, ctlPty = cpy;
var prevCmd = ca[ca.length - 1];
if(prevCmd.command === 'Q') {
ctlPtx = cpx + (cpx - prevCmd.points[0]);
ctlPty = cpy + (cpy - prevCmd.points[1]);
}
cpx += p.shift();
cpy += p.shift();
cmd = 'Q';
points.push(ctlPtx, ctlPty, cpx, cpy);
break;
case 'A':
var rx = p.shift(), ry = p.shift(), psi = p.shift(), fa = p.shift(), fs = p.shift();
var x1 = cpx, y1 = cpy;
cpx = p.shift(), cpy = p.shift();
cmd = 'A';
points = this._convertEndpointToCenterParameterization(x1, y1, cpx, cpy, fa, fs, rx, ry, psi);
break;
case 'a':
var rx = p.shift(), ry = p.shift(), psi = p.shift(), fa = p.shift(), fs = p.shift();
var x1 = cpx, y1 = cpy;
cpx += p.shift(), cpy += p.shift();
cmd = 'A';
points = this._convertEndpointToCenterParameterization(x1, y1, cpx, cpy, fa, fs, rx, ry, psi);
break;
}
ca.push({
command: cmd || c,
points: points
});
}
if(c === 'z' || c === 'Z')
ca.push({
command: 'z',
points: []
});
}
return ca;
},
/**
* get SVG path data string
*/
getData: function() {
return this.attrs.data;
},
/**
* set SVG path data string. This method
* also automatically parses the data string
* into a data array. Currently supported SVG data:
* M, m, L, l, H, h, V, v, Q, q, T, t, C, c, S, s, A, a, Z, z
* @param {String} SVG path command string
*/
setData: function(data) {
this.attrs.data = data;
this.dataArray = this.getDataArray();
},
_convertEndpointToCenterParameterization: function(x1, y1, x2, y2, fa, fs, rx, ry, psiDeg) {
// Derived from: http://www.w3.org/TR/SVG/implnote.html#ArcImplementationNotes
var psi = psiDeg * (Math.PI / 180.0);
var xp = Math.cos(psi) * (x1 - x2) / 2.0 + Math.sin(psi) * (y1 - y2) / 2.0;
var yp = -1 * Math.sin(psi) * (x1 - x2) / 2.0 + Math.cos(psi) * (y1 - y2) / 2.0;
var lambda = (xp*xp) / (rx*rx) + (yp*yp) / (ry*ry);
if (lambda > 1) {
rx *= Math.sqrt(lambda);
ry *= Math.sqrt(lambda);
}
var f = Math.sqrt((((rx*rx) * (ry*ry)) - ((rx*rx) * (yp*yp)) - ((ry*ry) * (xp*xp))) / ((rx*rx) * (yp*yp) + (ry*ry) * (xp*xp)));
if (fa == fs) f *= -1;
if (isNaN(f)) f = 0;
var cxp = f * rx * yp / ry;
var cyp = f * -ry * xp / rx;
var cx = (x1 + x2) / 2.0 + Math.cos(psi) * cxp - Math.sin(psi) * cyp;
var cy = (y1 + y2) / 2.0 + Math.sin(psi) * cxp + Math.cos(psi) * cyp;
var vMag = function(v) { return Math.sqrt(v[0]*v[0] + v[1]*v[1]); }
var vRatio = function(u, v) { return (u[0]*v[0] + u[1]*v[1]) / (vMag(u) * vMag(v)) }
var vAngle = function(u, v) { return (u[0]*v[1] < u[1]*v[0] ? -1 : 1) * Math.acos(vRatio(u,v)); }
var theta = vAngle([1,0], [(xp - cxp) / rx, (yp - cyp) / ry]);
var u = [(xp - cxp) / rx, (yp - cyp) / ry];
var v = [(-1 * xp - cxp) / rx, (-1 * yp - cyp) / ry];
var dTheta = vAngle(u, v);
if (vRatio(u,v) <= -1) dTheta = Math.PI;
if (vRatio(u,v) >= 1) dTheta = 0;
if (fs == 0 && dTheta > 0) dTheta = dTheta - 2 * Math.PI;
if (fs == 1 && dTheta < 0) dTheta = dTheta + 2 * Math.PI;
return [cx, cy, rx, ry, theta, dTheta, psi, fs];
}
};
// extend Shape
Kinetic.GlobalObject.extend(Kinetic.Path, Kinetic.Shape);