glEdgeFlagPointerEXT.3gl




Name

  glEdgeFlagPointerEXT - define	an array of edge flags


C Specification

  void glEdgeFlagPointerEXT( GLsizei stride,
			     GLsizei count,
			     const GLboolean *pointer )


Parameters


  stride   Specifies the byte offset between consecutive edge flags.  If
	   stride is zero the edge flags are understood	to be tightly packed
	   in the array.

  count	   Specifies the number	of edge	flags, counting	from the first,	that
	   are static.

  pointer  Specifies a pointer to the first edge flag in the array.


Description

  glEdgeFlagPointerEXT specifies the location and data format of an array of
  boolean edge flags to use when rendering when using the vertex array
  extension. stride gives the byte stride from one edge flag to the next 
  allowing vertexes and attributes to be packed into a single array or stored 
  in separate arrays.  (Single-array storage may be more efficient on some 
  implementations.) count indicates the number of array elements (counting 
  from the first) that are static. Static elements may be modified by the 
  application, but once they are modified, the application must explicitly 
  respecify the array before using it for any rendering. When an edge flag 
  array is specified, stride, count and pointer are saved as client-side state, 
  and static array elements may be cached by the implementation.

  The edge flag	array is enabled and disabled using glEnable and glDisable
  with the argument GL_EDGE_FLAG_ARRAY_EXT. If enabled,	the edge flag array
  is used when glDrawArraysEXT or glArrayElementEXT is called.

  Use glDrawArraysEXT to define	a sequence of primitives (all of the same
  type)	from pre-specified vertex and vertex attribute arrays.	Use
  glArrayElementEXT to specify primitives by indexing vertexes and vertex
  attributes.

Notes

  Non-static array elements are	not accessed until glArrayElementEXT or
  glDrawArraysEXT is executed.

  By default the edge flag array is disabled and it won't be accessed when
  glArrayElementEXT or glDrawArraysEXT is called.



  Although it is not an error to call glEdgeFlagPointerEXT between the
  execution of glBegin and the corresponding execution of glEnd, the results
  are undefined.



  glEdgeFlagPointerEXT will typically be implemented on	the client side	with
  no protocol.


  Since	the edge flag array parameters are client side state, they are not
  saved	or restored by glPushAttrib and	glPopAttrib.


  glEdgeFlagPointerEXT commands	are not	entered	into display lists.


  glEdgeFlagPointerEXT 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.


Errors

  GL_INVALID_ENUM is generated if stride  or count is negative.

Associated Gets

  glIsEnabled with argument GL_EDGE_FLAG_ARRAY_EXT
  glGet	with argument GL_EDGE_FLAG_ARRAY_STRIDE_EXT
  glGet	with argument GL_EDGE_FLAG_ARRAY_COUNT_EXT
  glGetPointervEXT with	argument GL_EDGE_FLAG_ARRAY_POINTER_EXT

See Also

  glArrayElementEXT, glColorPointerEXT,	glDrawArraysEXT, glGetPointervEXT,
  glIndexPointerEXT, glNormalPointerEXT, glTexCoordPointerEXT,
  glVertexPointerEXT, glEnable



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Last Edited: Fri Feb 24, 1995

AFV