glArrayElement(3G) OpenGL Reference glArrayElement(3G)
NAME
glArrayElement - render a vertex using the specified vertex array element
C SPECIFICATION
void glArrayElement( GLint i )
PARAMETERS
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
GLVERTEXARRAY 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 GLVERTEXARRAY 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 per
individual 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 non-sequential 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.
SEE ALSO
glColorPointer, glDrawArrays, glEdgeFlagPointer, glGetPointerv,
glIndexPointer, glInterleavedArrays, glNormalPointer, glTexCoordPointer,
glVertexPointer
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