CanvasRenderingContext2D: createPattern() method

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

js

createPattern(image, repetition)

Parameters

image

An image to be used as the pattern's image. It can be any of the following:

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)

If repetition is specified as an empty string ("") or null (but not undefined), a value of "repeat" will be used.

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:

A flowery pattern

HTML

html

<canvas id="canvas" width="300" height="300"></canvas>

JavaScript

js

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

const img = new Image();
img.src = "canvas_createpattern.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

js

// 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