WEBGL_multi_draw: multiDrawElementsWEBGL() method
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
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.drawElements()
method.
Syntax
multiDrawElementsWEBGL(mode,
countsList, countsOffset,
type,
firstsList, firstsOffset,
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.
countsList-
An
Int32ArrayorArray(ofGLint) specifying a list of numbers of indices to be rendered. countsOffset-
A
GLUintdefining the starting point into thecountsListarray. - type
-
A
GLenumspecifying the type of the values in the element array buffer. Possible values are:gl.UNSIGNED_BYTEgl.UNSIGNED_SHORT- When using the
OES_element_index_uintextension:gl.UNSIGNED_INT
offsetsList-
An
Int32ArrayorArray(ofGLsizei) specifying a list of starting indices for the arrays of vector points. offsetsOffset-
A
GLuintdefining the starting point into theoffsetsListarray. 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 incountsListoroffsetsListare negative, agl.INVALID_VALUEerror is thrown.
Examples
const counts = new Int32Array(/* … */);
const offsets = new Int32Array(/* … */);
ext.multiDrawElementsWEBGL(
gl.TRIANGLES,
counts,
0,
gl.UNSIGNED_SHORT,
offsets,
0,
counts.length,
);
Specifications
| Specification |
|---|
| WebGL WEBGL_multi_draw Extension Specification> |
Browser compatibility
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