.TH gDPSetColorDither 3P local "Silicon Graphics, Inc."
.SH NAME
.upperok
gDPSetColorDither, gsDPSetColorDither
\- enable or disable RGB color dithering
.SH C SPECIFICATION
.nf
\f3#include "gbi.h"

gDPSetColorDither(Gfx *gdl, unsigned int type)

gsDPSetColorDither(unsigned int type)

\fP
.fi
.SH PARAMETERS
.TP 10
.I *gdl
graphics display list pointer.
.TP
.I type
choose type of color dithering, either
\f3G_CD_MAGICSQ\fP,
\f3G_CD_BAYER\fP,
\f3G_CD_NOISE\fP,
\f3G_CD_ENABLE\fP,
or
\f3G_CD_DISABLE\fP.
.SH DESCRIPTION
This command selects (or disables) various types of color dithering.
The RDP pipeline keeps individual color component values in 8 bit precision until the Memory Interface.
The framebuffer can only accept color components in 5 bit precision when using 16 bit per pixel framebuffer format.
Therefore, dithering may be necessary to remove Mach bands.
.PP
Ordered dither has the effect of "scattering" the original complete information into a pixel neighborhood region.
The video interface (VI) contains logic to "gather" or recover the original information within the pixel neighborhood during video display; this feature can be enabled
or disabled by calling 
.I osViSetSpecialFeatures (3P)
with either OS_VI_DITHER_FILTER_ON or OS_VI_DITHER_FILTER_OFF, respectively.
This yields the best results in removing Mach bands in the low color resolution format (5/5/5 RGB).
.PP
.B G_CD_MAGICSQ
an ordered pattern dither, the preferred choice if the video dither filtering is enabled.
.PP
.B G_CD_BAYER,
an ordered pattern dither - the "standard" Bayer matrix, the preferred choice if the video dither filtering is disabled.
.PP
.B G_CD_NOISE,
random noise dither.
.PP
.B G_CD_DISABLE,
no dithering.
.PP
.B G_CD_ENABLE,
enable random noise dither.
This is for Hardware 1 compatiblity only.
For Hardware 2, please use 
\f3G_CD_MAGICSQ\fP,
\f3G_CD_BAYER\fP,
\f3G_CD_NOISE\fP,
or
\f3G_CD_DISABLE\fP.
.PP
.SH SEE ALSO
.IR gDPSetAlphaDither (3P),
.IR osViSetSpecialFeatures (3P)