About the Palette Manager and System 7.0
requirements of the Operating System, your application, and other
applications, and it can do so across multiple screens. You can use the Palette Manager to ensure that a set of colors is available whenever one of your application's windows is active.
System software versions 6.0.5 and later, or those using the 32-Bit
supplied with the original QuickDraw, or no color at all. • set up and maintain collections of colors or grays
• manage shared color resources
• provide exact colors for displaying images
• initiate color table animation
Your application can specify a color as an RGB value, and
available on the hardware at the time the color is needed. On direct hardware,
the match is virtually exact; on indexed hardware, the match depends both on
the capabilities of the video device and on the color needs of the Operating
System and other applications. By creating a palette of colors for your
application, you ensure that appropriate colors are available when its window
becomes frontmost.
for your application's windows and the color look-up tables (CLUTs) that
contain the colors an indexed device can display. When your window is opened
against those in the color tables of all devices the window touches. The Palette Manager then loads colors into the color tables as needed, taking into ac count the sizes of the color tables and the importance you have placed on various
colors in your palette.
You create palettes as resources of type 'pltt'. In the palette resource you
specify the RGB colors your application needs. You can also indicate whether
each color needs to be matched exactly and, if not, how close a match is
required. You can tailor your palettes to different possible video
devices-indicating, for example, that certain colors in the palette should be
used with 4-bit pixel depths, that a different set should be used with 8-bit
pixel depths, and that neither set should be used with gray-scale devices.
Palettes can also be created from color tables.
devices. If the user moves your application window so that it overlaps one
gray-scale, one indexed- pixel, and one direct-pixel screen, the Palette Manager chooses appropriate grays and colors for all three. throughout the system. A set of default color tables for devices of various
colors when an application terminates, and, when your application begins
executing, it executes in an environment equipped with as broad a range of
colors or grays as the hardware allows.