Web/API/CanvasRenderingContext2D/isPointInPath

From Get docs


The CanvasRenderingContext2D.isPointInPath() method of the Canvas 2D API reports whether or not the specified point is contained in the current path.

Syntax

ctx.isPointInPath(x, y [, fillRule]);
ctx.isPointInPath(path, x, y [, fillRule]);

Parameters

x
The x-axis coordinate of the point to check, unaffected by the current transformation of the context.
y
The y-axis coordinate of the point to check, unaffected by the current transformation of the context.
fillRule
The algorithm by which to determine if a point is inside or outside the path. Possible values:
"nonzero"
path
A Path2D path to check against. If unspecified, the current path is used.

Return value

Boolean
A Boolean, which is true if the specified point is contained in the current or specified path, otherwise false.

Examples

Checking a point in the current path

This example uses the isPointInPath() method to check if a point is within the current path.

HTML

<canvas id="canvas"></canvas>
<p>In path: <code id="result">false</code></p>

JavaScript

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
const result = document.getElementById('result');

ctx.rect(10, 10, 100, 100);
ctx.fill();
result.innerText = ctx.isPointInPath(30, 70);

Result

Checking a point in the specified path

Whenever you move the mouse, this example checks whether the cursor is in a circular Path2D path. If yes, the circle becomes green, otherwise it is red.

HTML

<canvas id="canvas"></canvas>

JavaScript

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');

// Create circle
const circle = new Path2D();
circle.arc(150, 75, 50, 0, 2 * Math.PI);
ctx.fillStyle = 'red';
ctx.fill(circle);

// Listen for mouse moves
canvas.addEventListener('mousemove', function(event) {
  // Check whether point is inside circle
  if (ctx.isPointInPath(circle, event.offsetX, event.offsetY)) {
    ctx.fillStyle = 'green';
  }
  else {
    ctx.fillStyle = 'red';
  }

  // Draw circle
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  ctx.fill(circle);
});

Result

Specifications

Specification Status Comment
HTML Living StandardThe definition of 'CanvasRenderingContext2D.isPointInPath' in that specification. Living Standard

Browser compatibility

Update compatibility data on GitHub

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
isPointInPath Chrome

Full support Yes

Edge

Full support 12

Firefox

Full support 2

IE

Full support Yes

Opera

Full support Yes

Safari

Full support Yes

WebView Android

Full support Yes

Chrome Android

Full support Yes

Firefox Android

Full support 4

Opera Android

Full support Yes

Safari iOS

Full support Yes

Samsung Internet Android

Full support Yes

Path parameter Chrome

Full support Yes

Edge

Full support ≤18

Firefox

Full support 31

IE

No support No

Opera

Full support Yes

Safari

No support No

WebView Android

Full support Yes

Chrome Android

Full support Yes

Firefox Android

Full support 31

Opera Android

?

Safari iOS

?

Samsung Internet Android

Full support Yes

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown


Gecko-specific note

  • Prior to Gecko 7.0 (Firefox 7.0 / Thunderbird 7.0 / SeaMonkey 2.4), this method incorrectly failed to multiply the specified point's coordinates by the current transformation matrix before comparing it to the path. Now this method works correctly even if the context is rotated, scaled, or otherwise transformed.

See also