glMultiDrawElementsIndirectCount — render indexed primitives from array data, taking parameters and count from memory
void glMultiDrawElementsIndirectCount(
|
GLenum mode, |
| GLenum type, | |
| const void *indirect, | |
| GLintptr drawcount, | |
| GLsizei maxdrawcount, | |
GLsizei stride); |
mode
Specifies what kind of primitives to render.
Symbolic constants
GL_POINTS,
GL_LINE_STRIP,
GL_LINE_LOOP,
GL_LINES,
GL_LINE_STRIP_ADJACENCY,
GL_LINES_ADJACENCY,
GL_TRIANGLE_STRIP,
GL_TRIANGLE_FAN,
GL_TRIANGLES,
GL_TRIANGLE_STRIP_ADJACENCY,
GL_TRIANGLES_ADJACENCY, and
GL_PATCHES
are accepted.
type
Specifies the type of data in the buffer bound to the GL_ELEMENT_ARRAY_BUFFER binding. Must be one of
GL_UNSIGNED_BYTE, GL_UNSIGNED_SHORT, or
GL_UNSIGNED_INT.
indirect
Specifies the address of a structure containing an array of draw parameters.
drawcount
Specifies an offset (in bytes) into the buffer object bound to the GL_PARAMETER_BUFFER
binding point at which a single sizei typed value is stored. Must be a multiple of four.
maxdrawcount
Specifies the maximum number of draws that are expected to be stored in the buffer.
If the value stored at drawcount into the buffer is greater than maxdrawcount,
the implementation stops processing draws after maxdrawcount parameter sets.
stride
Specifies the distance in basic machine units between elements of the draw parameter array.
glMultiDrawElementsIndirectCount specifies multiple geometric primitives
with very few subroutine calls. glMultiDrawElementsIndirectCount behaves
similarly to glMultiDrawElementsIndirect,
execept that the drawcount parameter is stored in the buffer bound to the
GL_PARAMETER_BUFFER binding at the offset specified by drawcount.
The parameters addressed by indirect are packed into a structure
that takes the form (in C):
typedef struct {
uint count;
uint instanceCount;
uint firstIndex;
int baseVertex;
uint baseInstance;
} DrawElementsIndirectCommand;
If a buffer is bound to the GL_DRAW_INDIRECT_BUFFER binding at the time
of a call to glMultiDrawElementsIndirectCount, indirect
is interpreted as an offset, in basic machine units, into that buffer and the parameter
data is read from the buffer rather than from client memory.
Note that indices stored in client memory are not supported. If no buffer is bound to the
GL_ELEMENT_ARRAY_BUFFER binding, an error will be generated.
The results of the operation are undefined if the reservedMustBeZero member
of the parameter structure is non-zero. However, no error is generated in this case.
Vertex attributes that are modified by glMultiDrawElementsIndirectCount have an
unspecified value after glMultiDrawElementsIndirectCount returns. Attributes that aren't
modified remain well defined.
GL_INVALID_ENUM is generated if mode is not an accepted value.
GL_INVALID_VALUE is generated if stride is not a multiple of four.
GL_INVALID_VALUE is generated if drawcount is negative.
GL_INVALID_OPERATION is generated if no buffer is bound to the GL_ELEMENT_ARRAY_BUFFER
binding, or if such a buffer's data store is currently mapped.
GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to an
enabled array or to the GL_DRAW_INDIRECT_BUFFER binding and the buffer object's data store is currently mapped.
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 mode is GL_PATCHES
and no tessellation control shader is active.
GL_INVALID_OPERATION error is generated if no buffer is bound to the GL_PARAMETER_BUFFER binding point.
GL_INVALID_OPERATION error is generated if drawcount is not a multiple of four.
GL_INVALID_OPERATION error is generated if reading a sizei typed value
from the buffer bound to the GL_PARAMETER_BUFFER target at the offset specified
by drawcount would result in an out-of-bounds access.
| OpenGL Version | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Function / Feature Name | 2.0 | 2.1 | 3.0 | 3.1 | 3.2 | 3.3 | 4.0 | 4.1 | 4.2 | 4.3 | 4.4 | 4.5 | 4.6 |
glMultiDrawElementsIndirectCount
|
- | - | - | - | - | - | - | - | - | - | - | - | ✔ |
glDrawArrays, glDrawArraysInstanced, glDrawArraysIndirect, glDrawElements, glDrawRangeElements, glDrawElementsIndirect, glMultiDrawArraysIndirect glMultiDrawArraysIndirectCount glMultiDrawElementsIndirect
Copyright © 2010-2014 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. https://opencontent.org/openpub/.