CanvasRenderingContext2D.createLinearGradient()

The CanvasRenderingContext2D.createLinearGradient() method of the Canvas 2D API creates a gradient along the line given by the coordinates represented by the parameters. This method returns a linear CanvasGradient.

Syntax

CanvasGradient <var>ctx.createLinearGradient(x0, y0, x1, y1);</var>

Parameters

x0

The x axis of the coordinate of the start point.

y0

The y axis of the coordinate of the start point.

x1

The x axis of the coordinate of the end point.

y1

The y axis of the coordinate of the end point.

Return value

CanvasGradient

A linear CanvasGradient initialized with the specified line.

Examples

Using the createLinearGradient method

This is just a simple code snippet which uses the createLinearGradient method to create a CanvasGradient with the specified start and end points. Once created, you can use the CanvasGradient.addColorStop() method to define new stops on the gradient with specified offsets and colors. The gradient gets applied if you set it as the current fillStyle and gets drawn onto the canvas when using the fillRect() method, for example.

HTML

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

JavaScript

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

var gradient = ctx.createLinearGradient(0,0,200,0);
gradient.addColorStop(0,"green");
gradient.addColorStop(1,"white");
ctx.fillStyle = gradient;
ctx.fillRect(10,10,200,100);

Edit the code below and see your changes update live in the canvas:

<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">
var gradient = ctx.createLinearGradient(0,0,200,0);
gradient.addColorStop(0,"green");
gradient.addColorStop(1,"white");
ctx.fillStyle = gradient;
ctx.fillRect(10,10,200,100);</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

Gecko-specific notes

• Starting Gecko 2.0 (Firefox 4 / Thunderbird 3.3 / SeaMonkey 2.1), specifying non-finite values now throws NOT_SUPPORTED_ERR instead of SYNTAX_ERR.

See also

• The interface defining it, CanvasRenderingContext2D
• CanvasRenderingContext2D.createRadialGradient()