NAME
glMinmax
- define minmax table
C SPECIFICATION
void ggllMMiinnmmaaxx(
GLenum _t_a_r_g_e_t,
GLenum _i_n_t_e_r_n_a_l_f_o_r_m_a_t,
GLboolean _s_i_n_k )
PARAMETERS
-
_t_a_r_g_e_t
-
The minmax table whose parameters are to be set.
Must be
GGLL__MMIINNMMAAXX.
-
_i_n_t_e_r_n_a_l_f_o_r_m_a_t
-
The of entries in the minmax table.
Must be one of
GGLL__AALLPPHHAA,
GGLL__AALLPPHHAA44,
GGLL__AALLPPHHAA88,
GGLL__AALLPPHHAA1122,
GGLL__AALLPPHHAA1166,
GGLL__LLUUMMIINNAANNCCEE,
GGLL__LLUUMMIINNAANNCCEE44,
GGLL__LLUUMMIINNAANNCCEE88,
GGLL__LLUUMMIINNAANNCCEE1122,
GGLL__LLUUMMIINNAANNCCEE1166,
GGLL__LLUUMMIINNAANNCCEE__AALLPPHHAA,
GGLL__LLUUMMIINNAANNCCEE44__AALLPPHHAA44,
GGLL__LLUUMMIINNAANNCCEE66__AALLPPHHAA22,
GGLL__LLUUMMIINNAANNCCEE88__AALLPPHHAA88,
GGLL__LLUUMMIINNAANNCCEE1122__AALLPPHHAA44,
GGLL__LLUUMMIINNAANNCCEE1122__AALLPPHHAA1122,
GGLL__LLUUMMIINNAANNCCEE1166__AALLPPHHAA1166,
GGLL__RR33__GG33__BB22,
GGLL__RRGGBB,
GGLL__RRGGBB44,
GGLL__RRGGBB55,
GGLL__RRGGBB88,
GGLL__RRGGBB1100,
GGLL__RRGGBB1122,
GGLL__RRGGBB1166,
GGLL__RRGGBBAA,
GGLL__RRGGBBAA22,
GGLL__RRGGBBAA44,
GGLL__RRGGBB55__AA11,
GGLL__RRGGBBAA88,
GGLL__RRGGBB1100__AA22,
GGLL__RRGGBBAA1122, or
GGLL__RRGGBBAA1166.
-
_s_i_n_k
-
If GGLL__TTRRUUEE, pixels will be consumed by the minmax
process and no drawing or texture loading will take place.
If GGLL__FFAALLSSEE, pixels will proceed to the final conversion process after
minmax.
DESCRIPTION
When GGLL__MMIINNMMAAXX is enabled, the RGBA components of incoming pixels are
compared to the minimum and maximum values for each component, which are
stored in the 2-element minmax table.
(The first element stores the minima, and the second element stores
the maxima.)
If a pixel component is greater than the corresponding component
in the maximum element, then the maximum element is updated with the
pixel component value.
If a pixel component is less than the corresponding component in
the minimum element, then the minimum element is updated with the
pixel component value.
(In both cases, if the internal of the minmax table includes
luminance, then the R color component of incoming pixels is used
for comparison.)
The contents of the minmax table may be retrieved at a later time
by calling ggllGGeettMMiinnmmaaxx.
The minmax operation is enabled or disabled by calling ggllEEnnaabbllee or
ggllDDiissaabbllee, respectively, with an argument of GGLL__MMIINNMMAAXX.
ggllMMiinnmmaaxx redefines the current minmax table to have entries of the
specified by _i_n_t_e_r_n_a_l_f_o_r_m_a_t.
The maximum element is initialized with the smallest possible component
values, and the minimum element is initialized with the largest possible
component values.
The values in the previous minmax table, if any, are lost.
If _s_i_n_k is GGLL__TTRRUUEE, then pixels are discarded after minmax;
no further processing of the pixels takes place, and no drawing,
texture loading, or pixel readback will result.
NOTES
ggllMMiinnmmaaxx is present only if GGLL__AARRBB__iimmaaggiinngg is returned when ggllGGeettSSttrriinngg
is called with an argument of GGLL__EEXXTTEENNSSIIOONNSS.
ERRORS
GGLL__IINNVVAALLIIDD__EENNUUMM is generated if _t_a_r_g_e_t is not one of the allowable
values.
GGLL__IINNVVAALLIIDD__EENNUUMM is generated if _i_n_t_e_r_n_a_l_f_o_r_m_a_t is not one of the
allowable values.
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllMMiinnmmaaxx is executed
between the execution of ggllBBeeggiinn and the corresponding
execution of ggllEEnndd.
ASSOCIATED GETS
ggllGGeettMMiinnmmaaxxPPaarraammeetteerr
SEE ALSO
ggllGGeettMMiinnmmaaxx((33GG)),
ggllRReesseettMMiinnmmaaxx((33GG))