The WEBGL_multi_draw.multiDrawArraysInstancedWEBGL() method of the WebGL API renders multiple primitives from array data. It is identical to multiple calls to the gl.drawArraysInstanced() method.
On this page
WEBGL_multi_draw: multiDrawArraysInstancedWEBGL() method
Syntax
js
multiDrawArraysInstancedWEBGL(mode,
firstsList, firstsOffset,
countsList, countsOffset,
instanceCountsList, instanceCountsOffset,
drawCount);
Parameters
-
mode -
A
GLenumspecifying 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_STRIPgl.TRIANGLE_FANgl.TRIANGLES: Draws a triangle for a group of three vertices.
-
firstsList -
An
Int32ArrayorArray(ofGLint) specifying a list of starting indices for the arrays of vector points. -
firstsOffset -
A
GLuintdefining the starting point into thefirstsListsarray. -
countsList -
An
Int32ArrayorArray(ofGLsizei) specifying a list of numbers of indices to be rendered. -
countsOffset -
A
GLuintdefining the starting point into thecountsListarray. -
instanceCountsList -
An
Int32ArrayorArray(ofGLsizei) specifying a list of numbers of instances of the range of elements to execute. -
instanceCountsOffset -
A
GLuintdefining the starting point into theinstanceCountsListarray. -
drawCount -
A
GLsizeispecifying the number of instances of the range of elements to execute.
Return value
None.
Exceptions
- If
modeis not one of the accepted values, agl.INVALID_ENUMerror is thrown. - If
drawCountor items infirstsList,countsList, orinstanceCountsListare negative, agl.INVALID_VALUEerror is thrown. - if
gl.CURRENT_PROGRAMisnull, agl.INVALID_OPERATIONerror is thrown.
Examples
js
const firsts = new Int32Array(/* … */);
const counts = new Int32Array(/* … */);
const instanceCounts = new Int32Array(/* … */);
ext.multiDrawArraysInstancedWEBGL(
gl.TRIANGLES,
firsts,
0,
counts,
0,
instanceCounts,
0,
firsts.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 | |
multiDrawArraysInstancedWEBGL |
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/multiDrawArraysInstancedWEBGL