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WEBGL_multi_draw: multiDrawElementsInstancedWEBGL() method

The WEBGL_multi_draw.multiDrawElementsWEBGL() method of the WebGL API renders multiple primitives from array data. It is identical to multiple calls to the gl.drawElementsInstanced() method.

Syntax

js

multiDrawElementsInstancedWEBGL(mode,
    countsList, countsOffset,
    type,
    firstsList, firstsOffset,
    instanceCountsList, instanceCountsOffset,
    drawCount);

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.
countsList

An Int32Array or Array (of GLint) specifying a list of numbers of indices to be rendered.

countsOffset

A GLUint defining the starting point into the countsList array.

type

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

offsetsList

An Int32Array or Array (of GLsizei) specifying a list of starting indices for the arrays of vector points.

offsetsOffset

A GLuint defining the starting point into the offsetsList array.

instanceCountsList

An Int32Array or Array (of GLsizei) specifying a list of numbers of instances of the range of elements to execute.

instanceCountsOffset

A GLuint defining the starting point into the instanceCountsList array.

drawCount

A GLsizei specifying the number of instances of the range 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 drawCount or items in countsList, offsetsList, or instanceCountsList are negative, a gl.INVALID_VALUE error is thrown.

Examples

js

const counts = new Int32Array(/* … */);
const offsets = new Int32Array(/* … */);
const instanceCounts = new Int32Array(/* … */);
ext.multiDrawElementsInstancedWEBGL(
  gl.TRIANGLES,
  counts,
  0,
  gl.UNSIGNED_SHORT,
  offsets,
  0,
  instanceCounts,
  0,
  counts.length,
);

Specifications

Specification
WebGL WEBGL_multi_draw Extension Specification

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
multiDrawElementsInstancedWEBGL 86 86 No No 72 15 86 86 No No 15 14.0

See also

© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/WEBGL_multi_draw/multiDrawElementsInstancedWEBGL