kk@mcnc.org (Krzysztof Kozminski) (08/25/89)
In article <30894@ucbvax.BERKELEY.EDU> oster@dewey.soe.berkeley.edu.UUCP (David Phillip Oster) writes: >Conclusion: directly bit-twiddle an off-screen bitmap, then call CopyBits >to display it for you. It will save you much present pain, and still more >future pain. One more thing it may do is to speed up the screen refresh times. From my experiments, drawing rectangles and line segments into a bitmap that has rectangular clipRgn and visRgn is ~30% faster than doing the same drawing into a bitmap with either of these regions composed of two abutting rectangles (as you're likely to have if your window has its corner overlapped by another window). In one case, I managed to get 60-fold speedup of drawing (yup, that's sixty) by drawing into off-screen pixmap (with my own routines - no QD calls since I knew I did not have to clip anything and needed a nonstandard color merging mode) and then CopyBiting it. Summary: Off-screen bitmaps are great! KK -- Kris Kozminski kk@mcnc.org "The party was a masquerade; the guests were all wearing their faces."
boissier@irisa.irisa.fr (franck boissiere,externes ) (08/25/89)
From article <1357@speedy.mcnc.org>, by kk@mcnc.org (Krzysztof Kozminski): > One more thing it may do is to speed up the screen refresh times. From > my experiments, drawing rectangles and line segments into a bitmap that > has rectangular clipRgn and visRgn is ~30% faster than doing the same > drawing into a bitmap with either of these regions composed of two > abutting rectangles (as you're likely to have if your window has its > corner overlapped by another window). >a Does anyone know how clipping is handled for non rectangular clipRgn? Is it divied into a collection of rectangles? Franck Franck BOISSIERE boissier@irisa.irisa.fr Prototyping Lab Manager boissier@ccettix.UUCP C.C.E.T.T. B.P. 59 boissier%irisa.irisa.fr@uunet.uu.net 35512 CESSON SEVIGNE CEDEX FRANCE