glArrayElementEXT.3gl




Name

  glArrayElementEXT - specify the array	elements used to render	a vertex


C Specification

  void glArrayElementEXT( GLint	i )


Parameters


  i  Specifies an index	in the enabled arrays.

Description

  glArrayElementEXT commands are used within glBegin/glEnd pairs to specify
  vertex and attribute data for	point, line and	polygon	primitives. When
  glArrayElementEXT is called, a single	vertex is drawn, using vertex and
  attribute data taken from location i of the enabled arrays.

  Use glArrayElementEXT	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

  glArrayElementEXT may	be included in display lists. If glArrayElementEXT 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 glArrayElementEXT are undefined.

  glArrayElementEXT 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
  glBegin and the corresponding	execution of glEnd, the	result of such
  respecification is undefined.

  glArrayElementEXT 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 glGetString, when called with argument
  GL_EXTENSIONS, extension EXT_vertex_array is supported.

See Also

  glColorPointerEXT, glDrawArraysEXT, glEdgeFlagPointerEXT, glGetPointervEXT,
  glIndexPointerEXT, glNormalPointerEXT, glTexCoordPointerEXT,
  glVertexPointerEXT




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Last Edited: Mon, May 22, 1995

AFV