NAME¶

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

C SPECIFICATION¶

void glDispatchComputeIndirect(GLintptr indirect);

PARAMETERS¶

indirect

DESCRIPTION¶

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.

ERRORS¶

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.

ASSOCIATED GETS¶

glGet() with argument GL_MAX_COMPUTE_WORK_GROUP_COUNT

SEE ALSO¶

glDispatchCompute().

COPYRIGHT¶

Copyright © 2012 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/.

AUTHORS¶

opengl.org