NAME

glGetHistogram - get histogram table

C SPECIFICATION

void ggllGGeettHHiissttooggrraamm( 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,
                     GLvoid _*_v_a_l_u_e_s )

PARAMETERS

_t_a_r_g_e_t
Must be GGLL__HHIISSTTOOGGRRAAMM.
_r_e_s_e_t
If GGLL__TTRRUUEE, each component counter that is actually returned is reset to zero. (Other counters are unaffected.) If GGLL__FFAALLSSEE, none of the counters in the histogram table is modified.
_f_o_r_m_a_t
The of values 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
The type of values 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 histogram table.

DESCRIPTION

ggllGGeettHHiissttooggrraamm returns the current histogram table as a one-dimensional image with the same width as the histogram. No pixel transfer operations are performed on this image, but pixel storage modes that are applicable to 1D images are honored.

Color components that are requested in the specified _f_o_r_m_a_t, but which are not included in the internal of the histogram, are returned as zero. The assignments of internal color components to the components requested by _f_o_r_m_a_t are:

center;
lb lb
l l.
_
Internal Component   Resulting Component
_
Red                  Red
Green                Green
Blue                 Blue
Alpha                Alpha
Luminance            Red
_

NOTES

ggllGGeettHHiissttooggrraamm 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__HHIISSTTOOGGRRAAMM.

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 is not one of the allowable values.

GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllGGeettHHiissttooggrraamm is executed between the execution of ggllBBeeggiinn and the corresponding execution of ggllEEnndd.

GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if _t_y_p_e 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 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

ggllHHiissttooggrraamm((33GG)), ggllRReesseettHHiissttooggrraamm((33GG)), ggllGGeettHHiissttooggrraammPPaarraammeetteerr((33GG))