| Title |
Get the color depth in bits
per pixel of the current Windows display |
| Description |
We're back to Windows API
to get the color depth of the current Windows display. Color depth will
be retrieved in bits per pixel, 8 bits per pixel means 256 colors, 16
bits per pixel is what Windows calls high density color, etc. |
| Date |
10/11/2000 |
| Last revision |
|
Sometimes you may
need to find out how many colors you can use in your application. Windows API
is again here to tell us. There is a function called GetDeviceCaps that can
provide information about the capabilities of any given display device in Windows,
such as the screen or a printer. This function needs two parameters, the first
one is the HDC (device-context handle) of the device you want to retrieve information
from, the second one is an index to the kind of information you want to retrieve.
Windows API defines several constants to use as indexes for the second parameter
such as DRIVERVERSION, HORZRES, VERTRES and, of course, BITSPIXEL. We can just
provide the function with the HDC of the desktop window, as we can find in the
help file "Win32 Developer's References":
"The desktop window covers the entire screen. The desktop window
is the area on top of which all icons and other windows are painted."
Good enough for us right now. We have now all the elements we need, the call
to GetDeviceCaps will be:
| bitsPerPixel := GetDeviceCaps( GetDc( GetDesktopWindow),
BITSPIXEL); |
