fglEdgeFlagPointerEXT(3G) OpenGL Reference fglEdgeFlagPointerEXT(3G)NAME
fglEdgeFlagPointerEXT - define an array of edge flags
FORTRAN SPECIFICATION
SUBROUTINE fglEdgeFlagPointerEXT( INTEGER*4 stride,
INTEGER*4 count,
CHARACTER*8 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
fglEdgeFlagPointerEXT specifies the location and data format of an array
of boolean edge flags to use when rendering using the vertex array
extension. stride gives the byte stride from one edge flag to the next
allowing vertices 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 fglEnable and
fglDisable with the argument GL_EDGE_FLAG_ARRAY_EXT. If enabled, the edge
flag array is used when fglDrawArraysEXT or fglArrayElementEXT is called.
Use fglDrawArraysEXT to define a sequence of primitives (all of the same
type) from pre-specified vertex and vertex attribute arrays. Use
fglArrayElementEXT to specify primitives by indexing vertices and vertex
attributes.
NOTES
Non-static array elements are not accessed until fglArrayElementEXT or
fglDrawArraysEXT is executed.
By default the edge flag array is disabled and it won't be accessed when
fglArrayElementEXT or fglDrawArraysEXT is called.
Page 1
fglEdgeFlagPointerEXT(3G) OpenGL Reference fglEdgeFlagPointerEXT(3G)
Although it is not an error to call fglEdgeFlagPointerEXT between the
execution of fglBegin and the corresponding execution of fglEnd, the
results are undefined.
fglEdgeFlagPointerEXT 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 fglPushAttrib and fglPopAttrib.
fglEdgeFlagPointerEXT commands are not entered into display lists.
fglEdgeFlagPointerEXT 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.
ERRORS
GL_INVALID_ENUM is generated if stride or count is negative.
ASSOCIATED GETS
fglIsEnabled with argument GL_EDGE_FLAG_ARRAY_EXT
fglGet with argument GL_EDGE_FLAG_ARRAY_STRIDE_EXT
fglGet with argument GL_EDGE_FLAG_ARRAY_COUNT_EXT
fglGetPointervEXT with argument GL_EDGE_FLAG_ARRAY_POINTER_EXT
MACHINE DEPENDENCIES
On RealityEngine, RealityEngine2, and VTX systems, do not enable or
disable GL_VERTEX_ARRAY, GL_VERTEX_ARRAY_EXT, GL_NORMAL_ARRAY,
GL_NORMAL_ARRAY_EXT, GL_COLOR_ARRAY, GL_COLOR_ARRAY_EXT,
GL_INDEX_ARRAY,GL_INDEX_ARRAY_EXT, GL_TEXTURE_COORD_ARRAY,
GL_TEXTURE_COORD_ARRAY_EXT, GL_EDGE_FLAG_ARRAY or GL_EDGE_FLAG_ARRAY_EXT
between a call to fglNewList and the corresponding call to fglEndList.
Instead, enable or disable before the call to fglNewList.
SEE ALSO
fglArrayElementEXT, fglColorPointerEXT, fglDrawArraysEXT, fglEnable,
fglGetPointervEXT, fglIndexPointerEXT, fglNormalPointerEXT,
fglTexCoordPointerEXT, fglVertexPointerEXT
Page 2
