WebGL2RenderingContext: drawElementsInstanced() method

The WebGL2RenderingContext.drawElementsInstanced() method of the WebGL 2 API renders primitives from array data like the gl.drawElements() method. In addition, it can execute multiple instances of a set of elements.

Note: When using WebGL 1, the ANGLE_instanced_arrays extension can provide this method, too.

Syntax

js
drawElementsInstanced(mode, count, type, offset, instanceCount)

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.
count

A GLsizei specifying the number of elements to be rendered.

type

A GLenum specifying the type of the values in the element array buffer. Possible values are:

offset

A GLintptr specifying an offset in the element array buffer. Must be a valid multiple of the size of the given type.

instanceCount

A GLsizei specifying the number of instances of the set of elements to execute.

Return value

None (undefined).

Exceptions

  • If mode is not one of the accepted values, a gl.INVALID_ENUM error is thrown.
  • If offset is a valid multiple of the size of the given type, a gl.INVALID_OPERATION error is thrown.
  • If count or instanceCount are negative, a gl.INVALID_VALUE error is thrown.

Examples

js
gl.drawElementsInstanced(gl.POINTS, 2, gl.UNSIGNED_SHORT, 0, 4);

Specifications

Specification
WebGL 2.0 Specification
# 3.7.9

Browser compatibility

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See also