WebGL2RenderingContext.drawElementsInstanced

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.

Syntax

void gl.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:

• gl.UNSIGNED_BYTE
• gl.UNSIGNED_SHORT
• When using the OES_element_index_uint extension:
  • gl.UNSIGNED_INT

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.

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

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

Specifications

Specification	Status	Comment
WebGL 2.0 The definition of 'drawElementsInstanced' in that specification.	Editor's Draft	Initial definition for WebGL.
OpenGL ES 3.0 The definition of 'glDrawElementsInstanced' in that specification.	Standard	Man page of the (similar) OpenGL API.

Browser compatibility

See also

• ext.drawArraysInstancedANGLE()
• ext.vertexAttribDivisorANGLE()
• WebGLRenderingContext.drawArrays()
• WebGLRenderingContext.drawElements()
• WebGL2RenderingContext.drawArraysInstanced()
• WebGL2RenderingContext.vertexAttribDivisor()