Web/API/WebGLRenderingContext/scissor

The WebGLRenderingContext.scissor() method of the WebGL API sets a scissor box, which limits the drawing to a specified rectangle.

Syntax

void gl.scissor(x, y, width, height);

Parameters

x: A GLint specifying the horizontal coordinate for the lower left corner of the box. Default value: 0.
y: A GLint specifying the vertical coordinate for the lower left corner of the box. Default value: 0.
width: A non-negative Glsizei specifying the width of the scissor box. Default value: width of the canvas.
height: A non-negative Glsizei specifying the height of the scissor box. Default value: height of the canvas.

Return value

None.

Exceptions

If either width or height is a negative value, a gl.INVALID_VALUE error is thrown.

Examples

When the scissor test is enabled, only pixels within the scissor box can be modified by drawing commands.

// turn on scissor test
gl.enable(gl.SCISSOR_TEST);

// set the scissor rectangle
gl.scissor(x, y, width, height);

// execute drawing commands in the scissor box (e.g. clear)

// turn off scissor test again
gl.disable(gl.SCISSOR_TEST);

To get the current scissor box dimensions, query the SCISSOR_BOX constant which returns an Int32Array.

gl.scissor(0, 0, 200, 200);
gl.getParameter(gl.SCISSOR_BOX);
// Int32Array[0, 0, 200, 200]

Specifications

Specification	Status	Comment
WebGL 1.0The definition of 'scissor' in that specification.	Recommendation	Initial definition.
OpenGL ES 2.0The definition of 'glScissor' in that specification.	Standard	Man page of the OpenGL API.

Browser compatibility

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`scissor`	Chrome Full support 9	Edge Full support 12	Firefox Full support 4	IE Full support 11	Opera Full support 12	Safari Full support 5.1	WebView Android Full support Yes	Chrome Android Full support 25	Firefox Android Full support Yes	Opera Android Full support 12	Safari iOS Full support 8	Samsung Internet Android Full support 1.5

Legend

Full support: Full support