glDrawTransformFeedbackInstanced

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Render multiple instances of primitives using a count derived from a transform feedback object.

C Specification[edit]

void glDrawTransformFeedbackInstanced( GLenum mode, GLuint id, GLsizei instancecount );


Parameters[edit]

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.
id - Specifies the name of a transform feedback object from which to retrieve a primitive count.
instancecount - Specifies the number of instances of the geometry to render.


Description[edit]

 glDrawTransformFeedbackInstanced draws multiple copies of a range of primitives of a type specified by mode using a count retrieved from the transform feedback stream specified by stream of the transform feedback object specified by id . Calling glDrawTransformFeedbackInstanced is equivalent to calling glDrawArraysInstanced with mode and instancecount as specified, first set to zero, and count set to the number of vertices captured on vertex stream zero the last time transform feedback was active on the transform feedback object named by id .

Calling glDrawTransformFeedbackInstanced is equivalent to calling glDrawTransformFeedbackStreamInstanced with stream set to zero.


Errors[edit]

 GL_INVALID_ENUM is generated if mode is not an accepted value.

 GL_INVALID_VALUE is generated if id is not the name of a transform feedback object.

 GL_INVALID_VALUE is generated if stream is greater than or equal to the value of GL_MAX_VERTEX_STREAMS .

 GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to an enabled array 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 is generated if glEndTransformFeedback has never been called while the transform feedback object named by id was bound.


Version Support[edit]

 glDrawTransformFeedbackInstanced  4.2+

See Also[edit]

 glDrawArrays , glDrawArraysInstanced , glDrawElements , glDrawRangeElements , glDrawTransformFeedback , glDrawTransformFeedbackStreamInstanced .


Copyright[edit]

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. http://opencontent.org/openpub/.