CanvasRenderingContext2D: createPattern() method
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The CanvasRenderingContext2D.createPattern()
method of the Canvas 2D API creates a pattern using the specified image and repetition.
This method returns a CanvasPattern
.
This method doesn't draw anything to the canvas directly.
The pattern it creates must be assigned to the CanvasRenderingContext2D.fillStyle
or CanvasRenderingContext2D.strokeStyle
properties, after which it is applied to any subsequent drawing.
Syntax
createPattern(image, repetition)
Parameters
image
-
An image to be used as the pattern's image. It can be any of the following:
HTMLImageElement
(<img>
)SVGImageElement
(<image>
)HTMLVideoElement
(<video>
, by using the capture of the video)HTMLCanvasElement
(<canvas>
)ImageBitmap
OffscreenCanvas
VideoFrame
repetition
-
A string indicating how to repeat the pattern's image. Possible values are:
"repeat"
(both directions)"repeat-x"
(horizontal only)"repeat-y"
(vertical only)"no-repeat"
(neither direction)
A
null
value is treated the same as the empty string (""
): both are synonyms of"repeat"
.
Return value
CanvasPattern
-
An opaque object describing a pattern.
If the image
is not fully loaded (HTMLImageElement.complete
is false
), then null
is returned.
Examples
Creating a pattern from an image
This example uses the createPattern()
method to create a CanvasPattern
with a repeating source image.
Once created, the pattern is assigned to the canvas context's fill style and applied to a rectangle.
The original image looks like this:
HTML
<canvas id="canvas" width="300" height="300"></canvas>
JavaScript
const canvas = document.getElementById("canvas");
const ctx = canvas.getContext("2d");
const img = new Image();
img.src = "canvas_create_pattern.png";
// Only use the image after it's loaded
img.onload = () => {
const pattern = ctx.createPattern(img, "repeat");
ctx.fillStyle = pattern;
ctx.fillRect(0, 0, 300, 300);
};
Creating a pattern from a canvas
In this example we create a pattern from the contents of an offscreen canvas. We then apply it to the fill style of our primary canvas, and fill that canvas with the pattern.
JavaScript
// Create a pattern, offscreen
const patternCanvas = document.createElement("canvas");
const patternContext = patternCanvas.getContext("2d");
// Give the pattern a width and height of 50
patternCanvas.width = 50;
patternCanvas.height = 50;
// Give the pattern a background color and draw an arc
patternContext.fillStyle = "#fec";
patternContext.fillRect(0, 0, patternCanvas.width, patternCanvas.height);
patternContext.arc(0, 0, 50, 0, 0.5 * Math.PI);
patternContext.stroke();
// Create our primary canvas and fill it with the pattern
const canvas = document.createElement("canvas");
const ctx = canvas.getContext("2d");
const pattern = ctx.createPattern(patternCanvas, "repeat");
ctx.fillStyle = pattern;
ctx.fillRect(0, 0, canvas.width, canvas.height);
// Add our primary canvas to the webpage
document.body.appendChild(canvas);
Result
Specifications
Specification |
---|
HTML Standard # dom-context-2d-createpattern-dev |
Browser compatibility
BCD tables only load in the browser
See also
- The interface defining this method:
CanvasRenderingContext2D
CanvasPattern