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GLHINT(3G)                                       OpenGL 3.3                                       GLHINT(3G)



NAME
       glHint - specify implementation-specific hints

C SPECIFICATION
       void glHint(GLenum target, GLenum mode);

PARAMETERS
       target
           Specifies a symbolic constant indicating the behavior to be controlled.  GL_LINE_SMOOTH_HINT,
           GL_POLYGON_SMOOTH_HINT, GL_TEXTURE_COMPRESSION_HINT, and GL_FRAGMENT_SHADER_DERIVATIVE_HINT are
           accepted.

       mode
           Specifies a symbolic constant indicating the desired behavior.  GL_FASTEST, GL_NICEST, and
           GL_DONT_CARE are accepted.

DESCRIPTION
       Certain aspects of GL behavior, when there is room for interpretation, can be controlled with hints.
       A hint is specified with two arguments.  target is a symbolic constant indicating the behavior to be
       controlled, and mode is another symbolic constant indicating the desired behavior. The initial value
       for each target is GL_DONT_CARE.  mode can be one of the following:

       GL_FASTEST

           The most efficient option should be chosen.

       GL_NICEST

           The most correct, or highest quality, option should be chosen.

       GL_DONT_CARE

           No preference.

       Though the implementation aspects that can be hinted are well defined, the interpretation of the
       hints depends on the implementation. The hint aspects that can be specified with target, along with
       suggested semantics, are as follows:

       GL_FRAGMENT_SHADER_DERIVATIVE_HINT

           Indicates the accuracy of the derivative calculation for the GL shading language fragment
           processing built-in functions: dFdx, dFdy, and fwidth.

       GL_LINE_SMOOTH_HINT

           Indicates the sampling quality of antialiased lines. If a larger filter function is applied,
           hinting GL_NICEST can result in more pixel fragments being generated during rasterization.

       GL_POLYGON_SMOOTH_HINT

           Indicates the sampling quality of antialiased polygons. Hinting GL_NICEST can result in more
           pixel fragments being generated during rasterization, if a larger filter function is applied.

       GL_TEXTURE_COMPRESSION_HINT

           Indicates the quality and performance of the compressing texture images. Hinting GL_FASTEST
           indicates that texture images should be compressed as quickly as possible, while GL_NICEST
           indicates that texture images should be compressed with as little image quality loss as possible.
           GL_NICEST should be selected if the texture is to be retrieved by glGetCompressedTexImage() for
           reuse.

NOTES
       The interpretation of hints depends on the implementation. Some implementations ignore glHint
       settings.

ERRORS
       GL_INVALID_ENUM is generated if either target or mode is not an accepted value.

COPYRIGHT
       Copyright (C) 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software
       B License. For details, see http://oss.sgi.com/projects/FreeB/.



OpenGL 3.3                                       03/08/2011                                       GLHINT(3G)