NAME
glHint
- specify implementation-specific hints
C SPECIFICATION
void ggllHHiinntt(
GLenum _t_a_r_g_e_t,
GLenum _m_o_d_e )
PARAMETERS
-
_t_a_r_g_e_t
-
Specifies a symbolic constant indicating the behavior to be controlled.
GGLL__FFOOGG__HHIINNTT,
GGLL__LLIINNEE__SSMMOOOOTTHH__HHIINNTT,
GGLL__PPEERRSSPPEECCTTIIVVEE__CCOORRRREECCTTIIOONN__HHIINNTT,
GGLL__PPOOIINNTT__SSMMOOOOTTHH__HHIINNTT, and
GGLL__PPOOLLYYGGOONN__SSMMOOOOTTHH__HHIINNTT are accepted.
-
_m_o_d_e
-
Specifies a symbolic constant indicating the desired behavior.
GGLL__FFAASSTTEESSTT,
GGLL__NNIICCEESSTT, and
GGLL__DDOONNTT__CCAARREE 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.
_t_a_r_g_e_t is a symbolic
constant indicating the behavior to be controlled,
and _m_o_d_e is another symbolic constant indicating the desired
behavior. The initial value for each _t_a_r_g_e_t is GGLL__DDOONNTT__CCAARREE.
_m_o_d_e can be one of the following:
-
GGLL__FFAASSTTEESSTT
-
The most efficient option should be chosen.
-
GGLL__NNIICCEESSTT
-
The most correct,
or highest quality,
option should be chosen.
-
GGLL__DDOONNTT__CCAARREE
-
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 _t_a_r_g_e_t,
along with suggested semantics,
are as follows:
-
GGLL__FFOOGG__HHIINNTT
-
Indicates the accuracy of fog calculation.
If per-pixel fog calculation is not efficiently supported
by the GL implementation,
hinting GGLL__DDOONNTT__CCAARREE or GGLL__FFAASSTTEESSTT can result in per-vertex
calculation of fog effects.
-
GGLL__LLIINNEE__SSMMOOOOTTHH__HHIINNTT
-
Indicates the sampling quality of antialiased lines.
If a larger filter function is applied, hinting GGLL__NNIICCEESSTT can
result in more pixel fragments being generated during rasterization,
-
GGLL__PPEERRSSPPEECCTTIIVVEE__CCOORRRREECCTTIIOONN__HHIINNTT
-
Indicates the quality of color and texture coordinate interpolation.
If perspective-corrected parameter interpolation is not efficiently supported
by the GL implementation,
hinting GGLL__DDOONNTT__CCAARREE or GGLL__FFAASSTTEESSTT can result in simple linear
interpolation of colors and/or texture coordinates.
-
GGLL__PPOOIINNTT__SSMMOOOOTTHH__HHIINNTT
-
Indicates the sampling quality of antialiased points.
If a larger filter function is applied, hinting GGLL__NNIICCEESSTT can
result in more pixel fragments being generated during rasterization,
-
GGLL__PPOOLLYYGGOONN__SSMMOOOOTTHH__HHIINNTT
-
Indicates the sampling quality of antialiased polygons.
Hinting GGLL__NNIICCEESSTT 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 ggllHHiinntt settings.
ERRORS
GGLL__IINNVVAALLIIDD__EENNUUMM is generated if either _t_a_r_g_e_t or _m_o_d_e is not
an accepted value.
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllHHiinntt
is executed between the execution of ggllBBeeggiinn
and the corresponding execution of ggllEEnndd.