indirect
glDispatchComputeIndirect launches one or more compute work groups using parameters stored in the buffer object currently bound to the GL_DISPATCH_INDIRECT_BUFFER target. Each work group is processed by the active program object for the compute shader stage. While the individual shader invocations within a work group are executed as a unit, work groups are executed completely independently and in unspecified order. indirect contains the offset into the data store of the buffer object bound to the GL_DISPATCH_INDIRECT_BUFFER target at which the parameters are stored.
The parameters addressed by indirect are packed a structure, which takes the form (in C):
typedef struct {
uint num_groups_x;
uint num_groups_y;
uint num_groups_z;
} DispatchIndirectCommand;
A call to glDispatchComputeIndirect is equivalent, assuming no errors are generated, to:
cmd = (const DispatchIndirectCommand *)indirect;
glDispatchComputeIndirect(cmd->num_groups_x, cmd->num_groups_y, cmd->num_groups_z);
Unlike glDispatchCompute(), no error is generated if any of the num_groups_x, num_groups_y or num_groups_z members of the DispatchIndirectCommand is larger than the value of GL_MAX_COMPUTE_WORK_GROUP_COUNT for the corresponding dimension. In such circumstances, behavior is undefined and may lead to application termination.
GL_INVALID_OPERATION is generated if there is no active program for the compute shader stage.
GL_INVALID_VALUE is generated if indirect is less than zero or not a multiple of four.
GL_INVALID_OPERATION is generated if no buffer is bound to the GL_DISPATCH_INDIRECT_BUFFER target or if the command would source data beyond the end of the buffer object's data store.
glGet() with argument GL_MAX_COMPUTE_WORK_GROUP_COUNT
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OpenGL Version
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| 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
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| glDispatchComputeIndirect | - | - | - | - | - | - | - | - | - | ✔ | ✔ |
✔
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Copyright © 2013-2014 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. m[blue]http://opencontent.org/openpub/m[].