fglArrayElementEXT(3G) OpenGL Reference fglArrayElementEXT(3G)NAME
fglArrayElementEXT - specify the array elements used to render a vertex
FORTRAN SPECIFICATION
SUBROUTINE fglArrayElementEXT( INTEGER*4 i )
PARAMETERS
i Specifies an index in the enabled arrays.
DESCRIPTION
fglArrayElementEXT commands are used within fglBegin/fglEnd pairs to
specify vertex and/or attribute data for point, line and polygon
primitives. If GL_VERTEX_ARRAY_EXT is enabled when fglArrayElementEXT is
called, then a single vertex is drawn, using vertex and attribute data
taken from location i of the enabled arrays. If GL_VERTEX_ARRAY_EXT is
not enabled then no drawing occurs but the attributes corresponding to
the enabled arrays are modified.
Use fglArrayElementEXT 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.
NOTES
fglArrayElementEXT may be included in display lists. If
fglArrayElementEXT 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.
Static array data may be read and cached by the implementation at any
time. If static array elements are modified and the arrays are not
respecified, the results of any subsequent calls to fglArrayElementEXT
are undefined.
fglArrayElementEXT executes even if GL_VERTEX_ARRAY_EXT is not enabled.
No drawing occurs in this case, but the attributes corresponding to
enabled arrays are modified.
Although it is not an error to respecify an array between the execution
of fglBegin and the corresponding execution of fglEnd, the result of such
respecification is undefined.
fglArrayElementEXT is part of the EXT_vertex_array extension, not part of
the core GL command set. If GL_EXT_vertex_array is included in the string
returned by fglGetString, when called with argument GL_EXTENSIONS,
extension EXT_vertex_array is supported.
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fglArrayElementEXT(3G) OpenGL Reference fglArrayElementEXT(3G)SEE ALSO
fglColorPointerEXT, fglDrawArraysEXT, fglEdgeFlagPointerEXT,
fglGetPointervEXT, fglIndexPointerEXT, fglNormalPointerEXT,
fglTexCoordPointerEXT, fglVertexPointerEXT
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