WebGLRenderingContext: drawArrays() 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.

Note: This feature is available in Web Workers.

The WebGLRenderingContext.drawArrays() method of the WebGL API renders primitives from array data.

Syntax

js
drawArrays(mode, first, count)

Parameters

mode

A GLenum specifying the type primitive to render. Possible values are:

  • gl.POINTS: Draws a single dot.
  • gl.LINE_STRIP: Draws a straight line to the next vertex.
  • gl.LINE_LOOP: Draws a straight line to the next vertex, and connects the last vertex back to the first.
  • gl.LINES: Draws a line between a pair of vertices.
  • gl.TRIANGLE_STRIP
  • gl.TRIANGLE_FAN
  • gl.TRIANGLES: Draws a triangle for a group of three vertices.

Note: If mode is POINTS, gl_PointSize may need to be set for drawArrays to render, as its value is unknown if not explicitly written. Only some GPUs set its default as 1.0.

first

A GLint specifying the starting index in the array of vector points.

count

A GLsizei specifying the number of indices to be rendered.

Return value

None (undefined).

Exceptions

  • If mode is not one of the accepted values, a gl.INVALID_ENUM error is thrown.
  • If first or count are negative, a gl.INVALID_VALUE error is thrown.
  • if gl.CURRENT_PROGRAM is null, a gl.INVALID_OPERATION error is thrown.

Examples

js
gl.drawArrays(gl.POINTS, 0, 8);

Specifications

Specification
WebGL Specification
# 5.14.11

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
drawArrays

Legend

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Full support
Full support

See also