Signature
Parameters
| Variables | Description |
|---|---|
| i |
Specifies an index into the enabled vertex data arrays.
|
Description
glArrayElement
commands are used within
glBegin
/
glEnd
pairs to
specify vertex and attribute data for point, line, and polygon
primitives. If
GL_VERTEX_ARRAY
is enabled when
glArrayElement
is called, a
single vertex is drawn, using
vertex and attribute data taken from location
i
of the enabled
arrays. If
GL_VERTEX_ARRAY
is not enabled, no drawing occurs but
the attributes corresponding to the enabled arrays are modified.
Use
glArrayElement
to construct primitives by indexing vertex data, rather than
by streaming through arrays of data in first-to-last order. Because
each call specifies only a single vertex, it is possible to explicitly
specify per-primitive attributes such as a single normal for each
triangle.
Changes made to array data between the execution of
glBegin
and the
corresponding execution of
glEnd
may affect calls to
glArrayElement
that are made
within the same
glBegin
/
glEnd
period in nonsequential ways.
That is, a call to
glArrayElement
that precedes a change to array data may
access the changed data, and a call that follows a change to array data
may access original data.
Notes
glArrayElement
is available only if the GL version is 1.1 or greater.
glArrayElement
is included in display lists. If
glArrayElement
is entered into a
display list, the necessary array data (determined by the array
pointers and enables) is also entered into the display list. Because
the array pointers and enables are client-side state, their values
affect display lists when the lists are created, not when the lists
are executed.
Errors
GL_INVALID_VALUE
may be generated if
i
is negative.
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.
See Also
Copyright
Copyright
1991-2006
Silicon Graphics, Inc. This document is licensed under the SGI
Free Software B License. For details, see
http://oss.sgi.com/projects/FreeB/
.
Sample Code References
The following code samples have been found which appear to reference the functions described here. Take care that the code may be old, broken or not even use PyOpenGL.
glArrayElement