CanvasRenderingContext2D.isPointInStroke()

The CanvasRenderingContext2D.isPointInStroke() method of the Canvas 2D API reports whether or not the specified point is inside the area contained by the stroking of a path.

Syntax

JavaScript
boolean <var>ctx.isPointInStroke(x, y);
<var>boolean <var>ctx.isPointInStroke(path, x, y);</var></var></var>

Parameters

x
The X coordinate of the point to check.
y
The Y coordinate of the point to check.
path
A Path2D path to use.

Return value

Boolean
A Boolean, which is true if the point is inside the area contained by the stroking of a path, otherwise false.

Examples

Using the isPointInStroke method

This is just a simple code snippet which uses the isPointInStroke method to check if a point is inside the area contained by the stroking of a path.

HTML

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

JavaScript

JavaScript
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");

ctx.rect(10, 10, 100, 100);
ctx.stroke();
console.log(ctx.isPointInStroke(10, 10)); // true

Edit the code below, see your changes update live in the canvas and watch for loggings in your console:

Playable code
HTML
<canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas>
<div class="playable-buttons">
  <input id="edit" type="button" value="Edit" />
  <input id="reset" type="button" value="Reset" />
</div>
<textarea id="code" class="playable-code">
ctx.rect(10, 10, 100, 100);
ctx.stroke();
console.log(ctx.isPointInStroke(10, 10)); // true</textarea>
JavaScript
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var textarea = document.getElementById("code");
var reset = document.getElementById("reset");
var edit = document.getElementById("edit");
var code = textarea.value;

function drawCanvas() {
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  eval(textarea.value);
}

reset.addEventListener("click", function() {
  textarea.value = code;
  drawCanvas();
});

edit.addEventListener("click", function() {
  textarea.focus();
})

textarea.addEventListener("input", drawCanvas);
window.addEventListener("load", drawCanvas);

Specifications

Specification Status Comment
WHATWG HTML Living Standard
The definition of 'CanvasRenderingContext2D.isPointInStroke' in that specification.
Living Standard  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) (Yes) (Yes) (Yes) (Yes)
Path parameter (Yes) 31 (31) Not supported (Yes) Not supported
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)
Path parameter ? ? 31.0 (31) ? ? ?

See also

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/canvasrenderingcontext2d/ispointinstroke

API Canvas CanvasRenderingContext2D Method Reference Référence