CanvasRenderingContext2D.shadowOffsetX - Web APIs 编辑

The CanvasRenderingContext2D.shadowOffsetX property of the Canvas 2D API specifies the distance that shadows will be offset horizontally.

Note: Shadows are only drawn if the shadowColor property is set to a non-transparent value. One of the shadowBlur, shadowOffsetX, or shadowOffsetY properties must be non-zero, as well.

Syntax

ctx.shadowOffsetX = offset;

offset

A float specifying the distance that shadows will be offset horizontally. Positive values are to the right, and negative to the left. The default value is 0 (no horizontal offset). Infinity and NaN values are ignored.

Examples

Moving a shadow horizontally

This example adds a blurred shadow to a rectangle. The shadowColor property sets its color, shadowOffsetX sets its offset 25 units to the right, and shadowBlur gives it a blur level of 10.

HTML

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

JavaScript

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

// Shadow
ctx.shadowColor = 'red';
ctx.shadowOffsetX = 25;
ctx.shadowBlur = 10;

// Rectangle
ctx.fillStyle = 'blue';
ctx.fillRect(20, 20, 150, 100);

Result

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• The interface defining this property: CanvasRenderingContext2D
• CanvasRenderingContext2D.shadowOffsetY
• CanvasRenderingContext2D.shadowColor
• CanvasRenderingContext2D.shadowBlur