GLDISPATCHCOMPUTEIND(3G) [FIXME: manual] GLDISPATCHCOMPUTEIND(3G)

glDispatchComputeIndirect - launch one or more compute work groups using parameters stored in a buffer

void glDispatchComputeIndirect(GLintptr indirect);

indirect
The offset into the buffer object currently bound to the GL_DISPATCH_INDIRECT_BUFFER buffer target at which the dispatch parameters are stored.

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;
glDispatchCompute(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

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
glDispatchComputeIndirect - - - - - - - - -

glDispatchCompute().

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. http://opencontent.org/openpub/.

Copyright © 2013-2014 Khronos Group
05/17/2020 [FIXME: source]