fglPrioritizeTexturesEXT(3G)

NAME
     fglPrioritizeTexturesEXT - set texture residence priority


FORTRAN SPECIFICATION
     SUBROUTINE fglPrioritizeTexturesEXT( INTEGER*4 n,
                                          CHARACTER*8 textures,
                                          CHARACTER*8 priorities )


PARAMETERS
     n           The number of textures to be prioritized.

     textures    An array containing the names of the textures to be
                 prioritized.

     priorities  An array containing the texture priorities.  A priority given
                 in an element of priorities applies to the texture named by
                 the corresponding element of textures.

DESCRIPTION
     fglPrioritizeTexturesEXT assigns the n texture priorities given in
     priorities to the n textures named in textures.

     On machines with a limited amount of texture memory, OpenGL establishes a
     ``working set'' of textures that are resident in texture memory.  These
     textures may be bound to a texture target much more efficiently than
     textures that are not resident.  By specifying a priority for each
     texture, fglPrioritizeTexturesEXT allows applications to guide the OpenGL
     implementation in determining which textures should be resident.

     The priorities given in priorities are clamped to the range [0.0, 1.0]
     before being assigned.  Zero indicates the lowest priority, and hence
     textures with priority zero are least likely to be resident.  One
     indicates the highest priority, and hence textures with priority one are
     most likely to be resident.  However, textures are not guaranteed to be
     resident until they are bound.

     fglPrioritizeTexturesEXT silently ignores attempts to prioritize texture
     zero, or any texture name that does not correspond to an existing
     texture.

     fglPrioritizeTexturesEXT does not require that any of the textures named
     by textures be bound to a texture target.  fglTexParameter may also be
     used to set a texture's priority, but only if the texture is currently
     bound.  This is the only way to set the priority of a default texture.

     fglPrioritizeTexturesEXT is included in display lists.
NOTES
     fglPrioritizeTexturesEXT is part of the EXT_texture_object extension.
     See fglIntro for more information about using extensions.

ERRORS
     GL_INVALID_VALUE is generated if n is negative.

     GL_INVALID_OPERATION is generated if fglPrioritizeTexturesEXT is executed
     between the execution of fglBegin and the corresponding execution of
     fglEnd.

ASSOCIATED GETS
     fglGetTexParameter with parameter name GL_TEXTURE_PRIORITY_EXT retrieves
     the priority of a currently-bound texture.


SEE ALSO
     fglAreTexturesResidentEXT, fglBindTextureEXT, fglTexImage1D,
     fglTexImage2D, fglTexImage3DEXT, fglTexParameter.