GLARRAYELEMENT(3gl)GLARRAYELEMENT(3gl)NAME
glArrayElement - render a vertex using the specified vertex array ele‐
ment
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
GL_VERTEX_ARRAY is enabled when glArrayElement is called, a single ver‐
tex 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 modi‐
fied.
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, glFog‐
CoordPointer, glIndexPointer, glInterleavedArrays, glNormalPointer,
glSecondaryColorPointer, glTexCoordPointer, glVertexPointer
15 Mar 97 GLARRAYELEMENT(3gl)