maunsell@cvs.rochester.edu (John Maunsell) (01/17/91)
I have several programs that save portions of the screen to an off-screen bitMap so that screen contents can be updated quickly at a later time. I've had no problems using bitMaps,i but I can't get off-screen pixMaps to work properly. The contents (lines, ovals, etc) of the restored region are returned intact, but the colors are often changed. My guess is that I am not handling the offscreen pixMap CLUT properly, but I don't know what to change. I am setting up the offscreen pixMap CLUT as described in Tech Note 120 (I haven't got a copy of Tech Note 277). Drawing off-screen and then copying to the screen seems to work. Any suggestions? John Maunsell University of Rochester maunsell@cvs.rochester.edu
hairston@henry.ece.cmu.edu (David Hairston) (01/17/91)
[maunsell@cvs.rochester.edu (John Maunsell) writes:] [] I have several programs that save portions of the screen to an [] off-screen bitMap so that screen contents can be updated quickly [] at a later time. I've had no problems using bitMaps,i but I can't [] get off-screen pixMaps to work properly. The contents (lines, ovals, [] etc) of the restored region are returned intact, but the colors are [] often changed. don't forget to set the high bit of <bitmap>.rowBytes to indicate that this bitmap is being used as a pixmap. i don't recall what TN.120 says but also don't forget to set the foreground color to black and the background color to white for CopyBits on PixMaps. (Ref. IM-V). i'm not sure this is your problem but these two areas are often overlooked. -dave- hairston@henry.ece.cmu.edu