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
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
orArray
(ofGLint
) specifying a list of numbers of indices to be rendered. countsOffset
-
A
GLUint
defining the starting point into thecountsList
array. - 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
-
offsetsList
-
An
Int32Array
orArray
(ofGLsizei
) specifying a list of starting indices for the arrays of vector points. offsetsOffset
-
A
GLuint
defining the starting point into theoffsetsList
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, agl.INVALID_ENUM
error is thrown. - If
drawCount
or items incountsList
oroffsetsList
are negative, agl.INVALID_VALUE
error 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
BCD tables only load in the browser