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.