NAME
glGetMinmax
- get minimum and maximum pixel values
C SPECIFICATION
void ggllGGeettMMiinnmmaaxx(
GLenum _t_a_r_g_e_t,
GLboolean _r_e_s_e_t,
GLenum _f_o_r_m_a_t,
GLenum _t_y_p_e_s,
GLvoid _*_v_a_l_u_e_s )
PARAMETERS
-
_t_a_r_g_e_t
-
Must be
GGLL__MMIINNMMAAXX.
-
_r_e_s_e_t
-
If GGLL__TTRRUUEE, all entries in the minmax table that are actually
returned are reset to their initial values. (Other entries are unaltered.)
If GGLL__FFAALLSSEE, the minmax table is unaltered.
-
_f_o_r_m_a_t
-
The of the data to be returned in _v_a_l_u_e_s.
Must be one of
GGLL__RREEDD,
GGLL__GGRREEEENN,
GGLL__BBLLUUEE,
GGLL__AALLPPHHAA,
GGLL__RRGGBB,
GGLL__BBGGRR,
GGLL__RRGGBBAA,
GGLL__BBGGRRAA,
GGLL__LLUUMMIINNAANNCCEE, or
GGLL__LLUUMMIINNAANNCCEE__AALLPPHHAA.
-
_t_y_p_e_s
-
The type of the data to be returned in _v_a_l_u_e_s.
Symbolic constants
GGLL__UUNNSSIIGGNNEEDD__BBYYTTEE,
GGLL__BBYYTTEE,
GGLL__BBIITTMMAAPP,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT,
GGLL__SSHHOORRTT,
GGLL__UUNNSSIIGGNNEEDD__IINNTT,
GGLL__IINNTT,
GGLL__FFLLOOAATT,
GGLL__UUNNSSIIGGNNEEDD__BBYYTTEE__33__33__22,
GGLL__UUNNSSIIGGNNEEDD__BBYYTTEE__22__33__33__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__55__66__55,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__55__66__55__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__44__44__44__44,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__44__44__44__44__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__55__55__55__11,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__11__55__55__55__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__IINNTT__88__88__88__88,
GGLL__UUNNSSIIGGNNEEDD__IINNTT__88__88__88__88__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__IINNTT__1100__1100__1100__22, and
GGLL__UUNNSSIIGGNNEEDD__IINNTT__22__1100__1100__1100__RREEVV
are accepted.
-
_v_a_l_u_e_s
-
A pointer to storage for the returned values.
DESCRIPTION
ggllGGeettMMiinnmmaaxx returns the accumulated minimum and maximum pixel values (computed on a
per-component basis) in a one-dimensional image of width 2. The first set
of return values are the minima, and the second set of return values
are the maxima.
The of the return values is determined by _f_o_r_m_a_t, and their type is
determined by _t_y_p_e_s.
No pixel transfer operations are performed on the return values, but pixel
storage modes that are applicable to 1-dimensional images are performed.
Color components that are requested in the specified _f_o_r_m_a_t, but that
are not included in the internal of the minmax table, are
returned as zero. The assignment of internal color components to the
components requested by _f_o_r_m_a_t are as follows:
center;
lb lb
l l.
_
Internal ComponentResulting Component
_
Red Red
Green Green
Blue Blue
Alpha Alpha
Luminance Red
_
If _r_e_s_e_t is GGLL__TTRRUUEE, the minmax table entries corresponding
to the return values are reset to their initial
values. Minimum and maximum values that are not returned are not
modified, even if _r_e_s_e_t is GGLL__TTRRUUEE.
NOTES
ggllGGeettMMiinnmmaaxx 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 GGLL__MMIINNMMAAXX.
GGLL__IINNVVAALLIIDD__EENNUUMM is generated if _f_o_r_m_a_t is not one of the allowable
values.
GGLL__IINNVVAALLIIDD__EENNUUMM is generated if _t_y_p_e_s is not one of the allowable
values.
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllGGeettMMiinnmmaaxx is executed
between the execution of ggllBBeeggiinn and the corresponding
execution of ggllEEnndd.
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if _t_y_p_e_s is one of
GGLL__UUNNSSIIGGNNEEDD__BBYYTTEE__33__33__22,
GGLL__UUNNSSIIGGNNEEDD__BBYYTTEE__22__33__33__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__55__66__55, or
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__55__66__55__RREEVV
and _f_o_r_m_a_t is not GGLL__RRGGBB.
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if _t_y_p_e_s is one of
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__44__44__44__44,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__44__44__44__44__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__55__55__55__11,
GGLL__UUNNSSIIGGNNEEDD__SSHHOORRTT__11__55__55__55__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__IINNTT__88__88__88__88,
GGLL__UUNNSSIIGGNNEEDD__IINNTT__88__88__88__88__RREEVV,
GGLL__UUNNSSIIGGNNEEDD__IINNTT__1100__1100__1100__22, or
GGLL__UUNNSSIIGGNNEEDD__IINNTT__22__1100__1100__1100__RREEVV
and _f_o_r_m_a_t is neither GGLL__RRGGBBAA nor GGLL__BBGGRRAA.
SEE ALSO
ggllMMiinnmmaaxx((33GG)),
ggllRReesseettMMiinnmmaaxx((33GG)),
ggllGGeettMMiinnmmaaxxPPaarraammeetteerr((33GG))