TheWebGL2RenderingContext.drawElementsInstanced() methodof theWebGL 2 API renders primitives fromarray data like thegl.drawElements() method. In addition, it can execute multiple instances of a setof elements.

Syntax

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

Parameters

mode

AGLenum specifying the type primitive to render. Possible valuesare:

• 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, andconnects 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

AGLsizei specifying the number of elements to be rendered.

type

AGLenum specifying the type of the values in the element arraybuffer. Possible values are:

• gl.UNSIGNED_BYTE
• gl.UNSIGNED_SHORT
• gl.UNSIGNED_INT When using theOES_element_index_uint extension.

offset

AGLintptr specifying an offset in the element array buffer. Must bea valid multiple of the size of the giventype.

instanceCount

AGLsizei specifying the number of instances of the set of elementsto execute.

Return value

None (undefined).

Exceptions

• Ifmode is not one of the accepted values, agl.INVALID_ENUM error is thrown.
• Ifoffset is a valid multiple of the size of the given type, agl.INVALID_OPERATION error is thrown.
• Ifcount orinstanceCount are negative, agl.INVALID_VALUE error is thrown.

Examples

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

Specifications

Browser compatibility

See also

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