thomas@duteca (Thomas Okken) (04/23/91)
There seem to be a number of QuickDraw bugs in System 7.0b4. Although I am not a developer, and probably shouldn't even have a copy of 7.0b4, I still think, if you find a bug, you might as well report it. CopyBits with mode=ditherCopy doesn't work properly when copying an 8-bit offscreen pixmap to a 1- or 8-bit screen. A straight copy is performed instead of dithered. Copying to a 2- or 4-bit screen works OK. DrawPicture to a 16- or 32-bit offscreen pixmap doesn't work properly; the r, g and b components seem to be shifted left within the pixel, and the blue component is set to $FF (in case of 32-bit pixmaps; similar things go wrong with 16-bit pixmaps). Because of this, reading a 32-bit PICT file by using DrawPicture with a bottleneck QD proc that reads from the file, doesn't work: the image is recognizable but becomes almost entirely blue. Both the above problems disappear when swithing to System 6.0.5 or 6.0.7 with 32-bit QuickDraw 1.2, and my code follows all pertinent IM and TN guidelines, so it seems these are real 7.0b4 bugs. Has anyone else encountered these? Is Apple aware of them? Anyone know of workarounds or fixes? - Thomas (thomas@duteca.et.tudelft.nl)
clay@claris.com (Clay A. Maeckel) (04/24/91)
thomas@duteca (Thomas Okken) writes: >DrawPicture to a 16- or 32-bit offscreen pixmap doesn't work properly; the >r, g and b components seem to be shifted left within the pixel, and the >blue component is set to $FF (in case of 32-bit pixmaps; similar things go >wrong with 16-bit pixmaps). I have heard of this problem just recently. It seems that people using DeskPicture on System 7 machines with 32-bit deep screens are getting "blue" pictures on their desktops. I've just starting tracking this down and hopefully it can be fixed before the "final" final submit, but I'm afraid it may be already too late. --Clay (author of DeskPicture) -- Clay Maeckel * Internet: clay@claris.com * * * (I know nothing!) * CompuServe: 73057,255 * v Claris Corporation * AppleLink: MAECKEL1 * \_____/