GLHINT

NAME

glHint - specify implementation-specific hints

C SPECIFICATION

void f3glHintfP( GLenum fItargetfP,

f2targetfP
Specifies a symbolic constant indicating the behavior to be controlled.
%f3GL_FOG_HINTfP,
%f3GL_LINE_SMOOTH_HINTfP,
%f3GL_PERSPECTIVE_CORRECTION_HINTfP,
%f3GL_POINT_SMOOTH_HINTfP, and
%f3GL_POLYGON_SMOOTH_HINTfP are accepted. 

f2modefP
Specifies a symbolic constant indicating the desired behavior.
%f3GL_FASTESTfP, 
%f3GL_NICESTfP, and 
%f3GL_DONT_CAREfP 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. f2targetfP is a symbolic constant indicating the behavior to be controlled, and f2modefP is another symbolic constant indicating the desired behavior. The initial value for each f2targetfP is %f3GL_DONT_CAREfP. f2modefP can be one of the following:

%f3GL_FASTESTfP: The most efficient option should be chosen.
%f3GL_NICESTfP: The most correct, or highest quality, option should be chosen.
%f3GL_DONT_CAREfP: 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 f2targetfP, along with suggested semantics, are as follows:
%f3GL_FOG_HINTfP: Indicates the accuracy of fog calculation. If per-pixel fog calculation is not efficiently supported by the GL implementation, hinting %f3GL_DONT_CAREfP or %f3GL_FASTESTfP can result in per-vertex calculation of fog effects.
%f3GL_LINE_SMOOTH_HINTfP: Indicates the sampling quality of antialiased lines. If a larger filter function is applied, hinting %f3GL_NICESTfP can result in more pixel fragments being generated during rasterization,
%f3GL_PERSPECTIVE_CORRECTION_HINTfP: Indicates the quality of color and texture coordinate interpolation. If perspective-corrected parameter interpolation is not efficiently supported by the GL implementation, hinting %f3GL_DONT_CAREfP or %f3GL_FASTESTfP can result in simple linear interpolation of colors and/or texture coordinates.
%f3GL_POINT_SMOOTH_HINTfP: Indicates the sampling quality of antialiased points. If a larger filter function is applied, hinting %f3GL_NICESTfP can result in more pixel fragments being generated during rasterization,
%f3GL_POLYGON_SMOOTH_HINTfP: Indicates the sampling quality of antialiased polygons. Hinting %f3GL_NICESTfP 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 implementations ignore %f3glHintfP settings.

ERRORS

%f3GL_INVALID_ENUMfP is generated if either f2targetfP or f2modefP is not an accepted value. %f3GL_INVALID_OPERATIONfP is generated if %f3glHintfP is executed between the execution of %f3glBeginfP and the corresponding execution of %f3glEndfP.