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

boolean ctx.isPointInStroke(x, y);
boolean ctx.isPointInStroke(path, x, y);

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

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

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:

<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>

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

Browser compatibility

See also

• The interface defining it, CanvasRenderingContext2D.