src/shapes/Path.ts
import { Factory } from '../Factory';
import { Shape, ShapeConfig } from '../Shape';
import { _registerNode } from '../Global';
import { GetSet, PathSegment } from '../types';
import {
getCubicArcLength,
getQuadraticArcLength,
t2length,
} from '../BezierFunctions';
export interface PathConfig extends ShapeConfig {
data?: string;
}
/**
* Path constructor.
* @author Jason Follas
* @constructor
* @memberof Konva
* @augments Konva.Shape
* @param {Object} config
* @param {String} config.data SVG data string
* @@shapeParams
* @@nodeParams
* @example
* var path = new Konva.Path({
* x: 240,
* y: 40,
* data: 'M12.582,9.551C3.251,16.237,0.921,29.021,7.08,38.564l-2.36,1.689l4.893,2.262l4.893,2.262l-0.568-5.36l-0.567-5.359l-2.365,1.694c-4.657-7.375-2.83-17.185,4.352-22.33c7.451-5.338,17.817-3.625,23.156,3.824c5.337,7.449,3.625,17.813-3.821,23.152l2.857,3.988c9.617-6.893,11.827-20.277,4.935-29.896C35.591,4.87,22.204,2.658,12.582,9.551z',
* fill: 'green',
* scaleX: 2,
* scaleY: 2
* });
*/
export class Path extends Shape<PathConfig> {
dataArray: PathSegment[] = [];
pathLength = 0;
constructor(config?: PathConfig) {
super(config);
this._readDataAttribute();
this.on('dataChange.konva', function () {
this._readDataAttribute();
});
}
_readDataAttribute() {
this.dataArray = Path.parsePathData(this.data());
this.pathLength = Path.getPathLength(this.dataArray);
}
_sceneFunc(context) {
var ca = this.dataArray;
// context position
context.beginPath();
var isClosed = false;
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':
isClosed = true;
context.closePath();
break;
}
}
if (!isClosed && !this.hasFill()) {
context.strokeShape(this);
} else {
context.fillStrokeShape(this);
}
}
getSelfRect() {
var points: Array<number> = [];
this.dataArray.forEach(function (data) {
if (data.command === 'A') {
// Approximates by breaking curve into line segments
var start = data.points[4];
// 4 = theta
var dTheta = data.points[5];
// 5 = dTheta
var end = data.points[4] + dTheta;
var inc = Math.PI / 180.0;
// 1 degree resolution
if (Math.abs(start - end) < inc) {
inc = Math.abs(start - end);
}
if (dTheta < 0) {
// clockwise
for (let t = start - inc; t > end; t -= inc) {
const point = Path.getPointOnEllipticalArc(
data.points[0],
data.points[1],
data.points[2],
data.points[3],
t,
0
);
points.push(point.x, point.y);
}
} else {
// counter-clockwise
for (let t = start + inc; t < end; t += inc) {
const point = Path.getPointOnEllipticalArc(
data.points[0],
data.points[1],
data.points[2],
data.points[3],
t,
0
);
points.push(point.x, point.y);
}
}
} else if (data.command === 'C') {
// Approximates by breaking curve into 100 line segments
for (let t = 0.0; t <= 1; t += 0.01) {
const point = Path.getPointOnCubicBezier(
t,
data.start.x,
data.start.y,
data.points[0],
data.points[1],
data.points[2],
data.points[3],
data.points[4],
data.points[5]
);
points.push(point.x, point.y);
}
} else {
// TODO: how can we calculate bezier curves better?
points = points.concat(data.points);
}
});
var minX = points[0];
var maxX = points[0];
var minY = points[1];
var maxY = points[1];
var x, y;
for (var i = 0; i < points.length / 2; i++) {
x = points[i * 2];
y = points[i * 2 + 1];
// skip bad values
if (!isNaN(x)) {
minX = Math.min(minX, x);
maxX = Math.max(maxX, x);
}
if (!isNaN(y)) {
minY = Math.min(minY, y);
maxY = Math.max(maxY, y);
}
}
return {
x: minX,
y: minY,
width: maxX - minX,
height: maxY - minY,
};
}
/**
* Return length of the path.
* @method
* @name Konva.Path#getLength
* @returns {Number} length
* @example
* var length = path.getLength();
*/
getLength() {
return this.pathLength;
}
/**
* Get point on path at specific length of the path
* @method
* @name Konva.Path#getPointAtLength
* @param {Number} length length
* @returns {Object} point {x,y} point
* @example
* var point = path.getPointAtLength(10);
*/
getPointAtLength(length) {
return Path.getPointAtLengthOfDataArray(length, this.dataArray);
}
data: GetSet<string, this>;
static getLineLength(x1, y1, x2, y2) {
return Math.sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1));
}
static getPathLength(dataArray: PathSegment[]) {
let pathLength = 0;
for (var i = 0; i < dataArray.length; ++i) {
pathLength += dataArray[i].pathLength;
}
return pathLength;
}
static getPointAtLengthOfDataArray(length: number, dataArray) {
var point,
i = 0,
ii = dataArray.length;
if (!ii) {
return null;
}
while (i < ii && length > dataArray[i].pathLength) {
length -= dataArray[i].pathLength;
++i;
}
if (i === ii) {
point = dataArray[i - 1].points.slice(-2);
return {
x: point[0],
y: point[1],
};
}
if (length < 0.01) {
point = dataArray[i].points.slice(0, 2);
return {
x: point[0],
y: point[1],
};
}
var cp = dataArray[i];
var p = cp.points;
switch (cp.command) {
case 'L':
return Path.getPointOnLine(length, cp.start.x, cp.start.y, p[0], p[1]);
case 'C':
return Path.getPointOnCubicBezier(
t2length(length, Path.getPathLength(dataArray), (i) => {
return getCubicArcLength(
[cp.start.x, p[0], p[2], p[4]],
[cp.start.y, p[1], p[3], p[5]],
i
);
}),
cp.start.x,
cp.start.y,
p[0],
p[1],
p[2],
p[3],
p[4],
p[5]
);
case 'Q':
return Path.getPointOnQuadraticBezier(
t2length(length, Path.getPathLength(dataArray), (i) => {
return getQuadraticArcLength(
[cp.start.x, p[0], p[2]],
[cp.start.y, p[1], p[3]],
i
);
}),
cp.start.x,
cp.start.y,
p[0],
p[1],
p[2],
p[3]
);
case 'A':
var cx = p[0],
cy = p[1],
rx = p[2],
ry = p[3],
theta = p[4],
dTheta = p[5],
psi = p[6];
theta += (dTheta * length) / cp.pathLength;
return Path.getPointOnEllipticalArc(cx, cy, rx, ry, theta, psi);
}
return null;
}
static getPointOnLine(dist, P1x, P1y, P2x, P2y, fromX?, fromY?) {
if (fromX === undefined) {
fromX = P1x;
}
if (fromY === undefined) {
fromY = P1y;
}
var m = (P2y - P1y) / (P2x - P1x + 0.00000001);
var run = Math.sqrt((dist * dist) / (1 + m * m));
if (P2x < P1x) {
run *= -1;
}
var rise = m * run;
var pt;
if (P2x === P1x) {
// vertical line
pt = {
x: fromX,
y: fromY + rise,
};
} else if ((fromY - P1y) / (fromX - P1x + 0.00000001) === m) {
pt = {
x: fromX + run,
y: fromY + rise,
};
} else {
var ix, iy;
var len = this.getLineLength(P1x, P1y, P2x, P2y);
// if (len < 0.00000001) {
// return {
// x: P1x,
// y: P1y,
// };
// }
var u = (fromX - P1x) * (P2x - P1x) + (fromY - P1y) * (P2y - P1y);
u = u / (len * len);
ix = P1x + u * (P2x - P1x);
iy = P1y + u * (P2y - P1y);
var pRise = this.getLineLength(fromX, fromY, ix, iy);
var pRun = Math.sqrt(dist * dist - pRise * pRise);
run = Math.sqrt((pRun * pRun) / (1 + m * m));
if (P2x < P1x) {
run *= -1;
}
rise = m * run;
pt = {
x: ix + run,
y: iy + rise,
};
}
return pt;
}
static getPointOnCubicBezier(pct, P1x, P1y, P2x, P2y, P3x, P3y, P4x, P4y) {
function CB1(t) {
return t * t * t;
}
function CB2(t) {
return 3 * t * t * (1 - t);
}
function CB3(t) {
return 3 * t * (1 - t) * (1 - t);
}
function CB4(t) {
return (1 - t) * (1 - t) * (1 - t);
}
var x = P4x * CB1(pct) + P3x * CB2(pct) + P2x * CB3(pct) + P1x * CB4(pct);
var y = P4y * CB1(pct) + P3y * CB2(pct) + P2y * CB3(pct) + P1y * CB4(pct);
return {
x: x,
y: y,
};
}
static getPointOnQuadraticBezier(pct, P1x, P1y, P2x, P2y, P3x, P3y) {
function QB1(t) {
return t * t;
}
function QB2(t) {
return 2 * t * (1 - t);
}
function QB3(t) {
return (1 - t) * (1 - t);
}
var x = P3x * QB1(pct) + P2x * QB2(pct) + P1x * QB3(pct);
var y = P3y * QB1(pct) + P2y * QB2(pct) + P1y * QB3(pct);
return {
x: x,
y: y,
};
}
static getPointOnEllipticalArc(
cx: number,
cy: number,
rx: number,
ry: number,
theta: number,
psi: number
) {
var cosPsi = Math.cos(psi),
sinPsi = Math.sin(psi);
var pt = {
x: rx * Math.cos(theta),
y: ry * Math.sin(theta),
};
return {
x: cx + (pt.x * cosPsi - pt.y * sinPsi),
y: cy + (pt.x * sinPsi + pt.y * cosPsi),
};
}
/*
* 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
*/
static parsePathData(data): PathSegment[] {
// 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
// return early if data is not defined
if (!data) {
return [];
}
// command string
var cs = 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: PathSegment[] = [];
var coords: string[] = [];
// init context point
var cpx = 0;
var cpy = 0;
var re = /([-+]?((\d+\.\d+)|((\d+)|(\.\d+)))(?:e[-+]?\d+)?)/gi;
var match;
for (n = 1; n < arr.length; n++) {
var str = arr[n];
var c = str.charAt(0);
str = str.slice(1);
coords.length = 0;
while ((match = re.exec(str))) {
coords.push(match[0]);
}
// while ((match = re.exec(str))) {
// coords.push(match[0]);
// }
var p: number[] = [];
for (var j = 0, jlen = coords.length; j < jlen; j++) {
// extra case for merged flags
if (coords[j] === '00') {
p.push(0, 0);
continue;
}
var parsed = parseFloat(coords[j]);
if (!isNaN(parsed)) {
p.push(parsed);
} else {
p.push(0);
}
}
while (p.length > 0) {
if (isNaN(p[0])) {
// case for a trailing comma before next command
break;
}
var cmd: string = '';
var points: number[] = [];
var startX = cpx,
startY = cpy;
// Move var from within the switch to up here (jshint)
var prevCmd, ctlPtx, ctlPty; // Ss, Tt
var rx, ry, psi, fa, fs, x1, y1; // Aa
// 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':
var dx = p.shift()!;
var dy = p.shift()!;
cpx += dx;
cpy += dy;
cmd = 'M';
// After closing the path move the current position
// to the the first point of the path (if any).
if (ca.length > 2 && ca[ca.length - 1].command === 'z') {
for (var idx = ca.length - 2; idx >= 0; idx--) {
if (ca[idx].command === 'M') {
cpx = ca[idx].points[0] + dx;
cpy = ca[idx].points[1] + dy;
break;
}
}
}
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':
ctlPtx = cpx;
ctlPty = cpy;
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':
ctlPtx = cpx;
ctlPty = cpy;
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':
ctlPtx = cpx;
ctlPty = cpy;
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':
ctlPtx = cpx;
ctlPty = cpy;
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':
rx = p.shift()!;
ry = p.shift()!;
psi = p.shift()!;
fa = p.shift()!;
fs = p.shift()!;
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':
rx = p.shift();
ry = p.shift();
psi = p.shift();
fa = p.shift();
fs = p.shift();
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,
start: {
x: startX,
y: startY,
},
pathLength: this.calcLength(startX, startY, cmd || c, points),
});
}
if (c === 'z' || c === 'Z') {
ca.push({
command: 'z',
points: [],
start: undefined as any,
pathLength: 0,
});
}
}
return ca;
}
static calcLength(x, y, cmd, points) {
var len, p1, p2, t;
var path = Path;
switch (cmd) {
case 'L':
return path.getLineLength(x, y, points[0], points[1]);
case 'C':
return getCubicArcLength(
[x, points[0], points[2], points[4]],
[y, points[1], points[3], points[5]],
1
);
case 'Q':
return getQuadraticArcLength(
[x, points[0], points[2]],
[y, points[1], points[3]],
1
);
case 'A':
// Approximates by breaking curve into line segments
len = 0.0;
var start = points[4];
// 4 = theta
var dTheta = points[5];
// 5 = dTheta
var end = points[4] + dTheta;
var inc = Math.PI / 180.0;
// 1 degree resolution
if (Math.abs(start - end) < inc) {
inc = Math.abs(start - end);
}
// Note: for purpose of calculating arc length, not going to worry about rotating X-axis by angle psi
p1 = path.getPointOnEllipticalArc(
points[0],
points[1],
points[2],
points[3],
start,
0
);
if (dTheta < 0) {
// clockwise
for (t = start - inc; t > end; t -= inc) {
p2 = path.getPointOnEllipticalArc(
points[0],
points[1],
points[2],
points[3],
t,
0
);
len += path.getLineLength(p1.x, p1.y, p2.x, p2.y);
p1 = p2;
}
} else {
// counter-clockwise
for (t = start + inc; t < end; t += inc) {
p2 = path.getPointOnEllipticalArc(
points[0],
points[1],
points[2],
points[3],
t,
0
);
len += path.getLineLength(p1.x, p1.y, p2.x, p2.y);
p1 = p2;
}
}
p2 = path.getPointOnEllipticalArc(
points[0],
points[1],
points[2],
points[3],
end,
0
);
len += path.getLineLength(p1.x, p1.y, p2.x, p2.y);
return len;
}
return 0;
}
static convertEndpointToCenterParameterization(
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];
}
}
Path.prototype.className = 'Path';
Path.prototype._attrsAffectingSize = ['data'];
_registerNode(Path);
/**
* get/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
* @name Konva.Path#data
* @method
* @param {String} data svg path string
* @returns {String}
* @example
* // get data
* var data = path.data();
*
* // set data
* path.data('M200,100h100v50z');
*/
Factory.addGetterSetter(Path, 'data');