glDrawElementsInstancedBaseVertex

render multiple instances of a set of primitives from array data with a per-element offset

Signature

glDrawElementsInstancedBaseVertex( GLenum ( mode ) , GLsizei ( count ) , GLenum ( type ) , void *( indices ) , GLsizei ( instancecount ) , GLint ( basevertex ) )-> void
glDrawElementsInstancedBaseVertex( mode , count , type , indices , instancecount , basevertex )

Parameters

VariablesDescription
mode
Specifies what kind of primitives to render. Symbolic constants GL_POINTS , GL_LINE_STRIP , GL_LINE_LOOP , GL_LINES , GL_TRIANGLE_STRIP , GL_TRIANGLE_FAN , GL_TRIANGLES , GL_LINES_ADJACENCY , GL_LINE_STRIP_ADJACENCY , GL_TRIANGLES_ADJACENCY , GL_TRIANGLE_STRIP_ADJACENCY and GL_PATCHES are accepted.
count
Specifies the number of elements to be rendered.
type
Specifies the type of the values in indices. Must be one of GL_UNSIGNED_BYTE , GL_UNSIGNED_SHORT , or GL_UNSIGNED_INT .
indices
Specifies a pointer to the location where the indices are stored.
instancecount
Specifies the number of instances of the indexed geometry that should be drawn.
basevertex
Specifies a constant that should be added to each element of indices when chosing elements from the enabled vertex arrays.

Description

glDrawElementsInstancedBaseVertex behaves identically to glDrawElementsInstanced except that the i th element transferred by the corresponding draw call will be taken from element indices [i] + basevertex of each enabled array. If the resulting value is larger than the maximum value representable by type , it is as if the calculation were upconverted to 32-bit unsigned integers (with wrapping on overflow conditions). The operation is undefined if the sum would be negative.

Notes

glDrawElementsInstancedBaseVertex is only supported if the GL version is 3.2 or greater.

Errors

GL_INVALID_ENUM is generated if mode is not an accepted value.
GL_INVALID_VALUE is generated if count or instancecount is negative.
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 a non-zero buffer object name is bound to an enabled array or the element array and the buffer object's data store is currently mapped.

Version Support

glDrawElementsInstancedBaseVertex

See Also

Copyright

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. .