Signature
glDrawElementsInstancedBaseVertexBaseInstance(
GLenum (
mode
)
,
GLsizei (
count
)
,
GLenum (
type
)
,
void *(
indices
)
,
GLsizei (
instancecount
)
,
GLint (
basevertex
)
,
GLuint (
baseinstance
)
)-> void
glDrawElementsInstancedBaseVertexBaseInstance(
mode
,
count
,
type
,
indices
,
instancecount
,
basevertex
,
baseinstance
)
Parameters
| Variables | Description |
|---|---|
| mode |
Specifies what kind of primitives to render.
Symbolic constants
GL_POINTS
,
GL_LINE_STRIP
,
GL_LINE_LOOP
,
GL_LINES
,
GL_TRIANGLE_STRIP
,
GL_TRIANGLE_FAN
,
GL_TRIANGLES
,
GL_LINES_ADJACENCY
,
GL_LINE_STRIP_ADJACENCY
,
GL_TRIANGLES_ADJACENCY
,
GL_TRIANGLE_STRIP_ADJACENCY
and
GL_PATCHES
are accepted.
|
| count |
Specifies the number of elements to be rendered.
|
| type |
Specifies the type of the values in indices. Must be one of
GL_UNSIGNED_BYTE
,
GL_UNSIGNED_SHORT
, or
GL_UNSIGNED_INT
.
|
| indices |
Specifies a pointer to the location where the indices are stored.
|
| instancecount |
Specifies the number of instances of the indexed geometry that should be drawn.
|
| basevertex |
Specifies a constant that should be added to each element of
indices
when chosing elements from the enabled vertex arrays.
|
| baseinstance |
Specifies the base instance for use in fetching instanced vertex attributes.
|
Description
glDrawElementsInstancedBaseVertexBaseInstance
behaves identically to
glDrawElementsInstanced
except that the
i
th element
transferred by the corresponding draw call will be taken from element
indices
[i] +
basevertex
of each enabled array. If the resulting value is larger than the maximum value representable by
type
,
it is as if the calculation were upconverted to 32-bit unsigned integers (with wrapping on overflow conditions).
The operation is undefined if the sum would be negative.
Specific vertex attributes may be classified as
instanced
through the use of
glVertexAttribDivisor
. Instanced vertex attributes
supply per-instance vertex data to the vertex shader. The index of the vertex fetched from the enabled instanced vertex
attribute arrays is calculated as
. Note that
baseinstance
does not affect the shader-visible value of
gl_InstanceID
.
Notes
glDrawElementsInstancedBaseVertex
is only supported if the GL version is 3.2 or greater.
Errors
GL_INVALID_ENUM
is generated if
mode
is not an accepted value.
GL_INVALID_OPERATION
is generated if a geometry shader is active and
mode
is incompatible with the input primitive type of the geometry shader in the currently installed program object.
GL_INVALID_OPERATION
is generated if a non-zero buffer object name is bound to an
enabled array or the element array and the buffer object's data store is currently mapped.
Version Support
| glDrawElementsInstancedBaseVertexBaseInstance |
See Also
Copyright
Copyright
2011-2014 Khronos Group.
This material may be distributed subject to the terms and conditions set forth in
the Open Publication License, v 1.0, 8 June 1999.
http://opencontent.org/openpub/
.
