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
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. instanceCountsList
-
An
Int32Array
orArray
(ofGLsizei
) specifying a list of numbers of instances of the range of elements to execute. instanceCountsOffset
-
A
GLuint
defining the starting point into theinstanceCountsList
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
,offsetsList
, orinstanceCountsList
are negative, agl.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
BCD tables only load in the browser