gdk-sharp2.6.0.0Gtk# is thread aware, but not thread safe; See the Gtk# Thread Programming for details.Describe the how pixel values are converted into RGB values for display.
Visuals are a very important concept that is often
overlooked. Roughly, a visual defines the memory
representation that a piece of hardware uses to store the
contents of an image. X supports different kinds of visuals to
suit the different kinds of hardware out there.
Some of this information comes from Federico Mena's excellent
"X Concepts" document from http://www.nuclecu.unam.mx/~federico/docs/x-concepts.
System.EnumGLib.GType(WrapperType=typeof(Gdk.VisualTypeGType))FieldGdk.VisualTypeStatic gray visuals are those in which you cannot change the gray intensities of the hardware.
Plain monochrome (B/W) displays or fixed 4-gray displays may
be of the static gray kind. Grayscale visuals are those in
which you can change the gray intensities used by the
hardware. Exotic 12-bit grayscale displays (as used for
medical visualization) that let you change the gray
intensities may be of the grayscale type.
FieldGdk.VisualTypeGrayscale visuals are used for displays that use a single channel of color information.
Black and white or grayscale monitors (including amber and
green monitors) may use this type of visual. These visuals
can be either static gray or grayscale.
FieldGdk.VisualTypeAn indexed color visual, where colors can not be changed.
Static color visuals are those in which you cannot change
the actual colors that the indexes correspond to (a static
palette). Remember the old CGA cards with four fixed colors
in graphics mode? These could be considered of the static
color type.
FieldGdk.VisualTypeAn indexed color visual, where colors can change.
Pseudo color visuals are those in which you can change the
actual colors that the indexes correspond to. Each index
maps to an RGB triplet that defines the color that will be
displayed on the screen. You can change these RGB triplets
for each index. Pseudo color visuals are very common in
graphics cards. Graphics cards with 256 colors that you can
change, for example, VGA cards, are of the pseudo color
type.
FieldGdk.VisualTypeTrue color visuals use the exact RGB values you specified
for a pixel
TrueColor visuals store explicit RGB values for every
pixel, instead of storing a single value like indexed
visuals.
TrueColor visuals map the RGB into the screens RGB values
without any changes. There is no transformation applied to
it.
FieldGdk.VisualTypeDirectColor visuals use RGB encoding, with a
correction palette.
TrueColor visuals store explicit RGB values for every
pixel, instead of storing a single value like indexed
visuals.
The values in a direct color visual go through an
indirection step before being sent to the display. Each of
the R/G/B values you specify is an index in separate
tables, and those tables contain a translated value. So an
RGB triplet gets translated into an R'G'B' triplet,
i.e. the three tables together define an f(r, g, b) ->
(r', g', b') function. For most purposes, your tables will
be filled by the identity function and you will get
linearly increasing intensity values for each of the RGB
channels. Things can become quite interesting, however,
when you modify the tables to have a nonlinear mapping. If
you fill them using an exponential function, you can do
color correction on hardware