[comp.windows.x] Setting and clearing planes

burdorf%zermatt@RAND.ORG (Chris Burdorf) (08/25/89)

In section 7.4.1 of "The Xlib Programming Manual", by Adrian Nye, there
is a discussion of allocating read/write colorcells for overlays.  The 
book gives an example on how to use XAllocColorCells to set up the colorcells.
It says "the underlying graphics won't be visible, but they can be refreshed by
simply setting or clearing one or more planes in the drawable."  The book then
gives code that builds the colorcells.   My question is how do you use these
colorcells to do the clearing and setting of the different planes?  It doesn't
look to me that I can use XClearArea or XClearWindow to do this.   
I tried using XSetPlaneMask with different planes, and also
used the values from the book's example (overlay_pixel_1, overlay_pixel_2,etc.)
as pixel arguments, but neither gave me the disired effect of drawing the
different colors into different planes.

Could someone please give me an example showing how the setting and clearing of
planes is done?

Thanks,

Chris Burdorf

burdorf@rand.org