glHint — specify implementation-specific hints
void glHint(GLenum target, GLenum mode);
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.
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.
The interpretation of hints depends on the implementation.
Some implementations ignore glHint settings.
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