On Mon, 11 Sep 2006, cckuo wrote: > HI: > After reading the HOWTO file, would you please help me to clarify some > questions about the meaning of the parameters that XAA pass to me? > (To minimize the difference, suppose all the flags I used below are > HARDWARE_PATTERN_SCREEN_ORIGIN | HARDWARE_PATTERN_PROGRAMMED_BITS > 1. What is the unit of (x,y) that pass by Subsequent function, bytes or > pixels? Since I have seen (0x312, 0x812) in hex pass to driver while my > resolution is (0x400, 0x300) in hex, that is (1024x768)? The XAA interface is always in pixels. If (0x312, 0x812) is the (x,y) then this is rendering offscreen to an offscreen pixmap or to the pixmap cache. > 2. Does HARDWARE_PATTERN_SCREEN_ORIGIN means the all the value of (x,y) that > pass subsequently are relative to upper-left corner of my on-screen memory, > that is, if on-screen is located from the physical memory, 0xd0000000, and > (x,y) is (0x10, 0), the destination address that HW should put the pattern > on after ropping is 0xd0000020, assuming the (x,y) is in pixel unit and the > screen depth is 16bpp. Is that right ? All x,y coordinates are relative to the upper-left of the on-screen memory in ALL cases. HARDWARE_PATTERN_SCREEN_ORIGIN refers to the source pattern alignment. It means the phase of the 8x8 pattern should be specified relative to the screen origin. Without that option it is relative to the origin of the rectangle being drawn. We are passing an 8x8 pattern to the hardware. If you want the first pixel in the pattern to correspond to the first pixel of the rectangle being drawn, then you do NOT want HARDWARE_PATTERN_SCREEN_ORIGIN to be set. Most hardware actually need the pattern specified relative to the origin of the surface being drawn on not the origin of the rectangle being drawn. At typical rendering case is where XAA needs to fill a large area with an 8x8 pattern but the destination is clipped by various occluding windows so the area ends up being filled with lots of smaller operations. If the pattern is specified relative to the destination surface then the pattern only needs to be specified once. If the pattern needs to be specified relative to each individual rectangle, then XAA needs to realign the 8x8 pattern for each rectangle. That is what happens when HARDWARE_PATTERN_SCREEN_ORIGIN is not set. A new realigned pattern is passed to the driver for every Subsequent call. Mark. > > Thanks for your help. > cckuo > > > The fail_pattern.jpg looks like the driver incorrectly sets > >the HARDWARE_PATTERN_SCREEN_ORIGIN flag. See section 2.6 of > >xc/programs/Xserver/hw/xfree86/xaa/XAA.HOWTO > > > > Mark. > > > > _______________________________________________ XFree86 mailing list XFree86@xxxxxxxxxxx http://XFree86.Org/mailman/listinfo/xfree86
