glHint(3) glHint(3)
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_FOG_HINT, GL_LINE_SMOOTH_HINT,
GL_PERSPECTIVE_CORRECTION_HINT, GL_POINT_SMOOTH_HINT, and
GL_POLYGON_SMOOTH_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_FOG_HINT Indicates the accuracy of fog calculation. If per-
pixel fog calculation is not efficiently supported
by the GL implementation, hinting GL_DONT_CARE or
GL_FASTEST can result in per-vertex calculation of
fog effects.
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 frag-
ments being generated during rasterization,
GL_PERSPECTIVE_CORRECTION_HINT
Indicates the quality of color and texture coordi-
nate interpolation. If perspective-corrected
parameter interpolation is not efficiently sup-
ported by the GL implementation, hinting
GL_DONT_CARE or GL_FASTEST can result in simple
linear interpolation of colors and/or texture coor-
dinates.
GL_POINT_SMOOTH_HINT
Indicates the sampling quality of antialiased
points. If a larger filter function is applied,
hinting GL_NICEST can result in more pixel frag-
ments being generated during rasterization,
GL_POLYGON_SMOOTH_HINT
Indicates the sampling quality of antialiased poly-
gons. Hinting GL_NICEST can result in more pixel
fragments being generated during rasterization, if
a larger filter function is applied.
NOTES
The interpretation of hints depends on the implementation. Some imple-
mentations ignore glHint settings.
ERRORS
GL_INVALID_ENUM is generated if either target or mode is not an
accepted value.
GL_INVALID_OPERATION is generated if glHint is executed between the
execution of glBegin and the corresponding execution of glEnd.
glHint(3)
Mac OS X 10.6 - Generated Thu Sep 17 20:20:23 CDT 2009