On Thu, 11 Jul 2002, Brian Paul wrote: > Leif Delgass wrote: > > > > I just discovered that the glean failures in blendFunc, logicOp, > > orthoPosRandTris, orthoPosRandRects, orthoPosTinyQuads, and polygonOffset > > are the result of an off-by-one error in the y screen coordinates. If I > > add one to the Y coordinate in the viewport conversion to screen > > coordinates, these tests all pass. However, it breaks the scissor test > > and the orthoPos[H,V]Lines and orthoPosPoints tests still fail (which > > could be a result of the implementation of points and lines with > > triangles/quads). It also seems to leave a row of pixels at the top of > > the window which isn't drawn on, but is cleared. The stipple test still > > has the same problem because lines still aren't conformant. I'm still a > > little puzzled as to where the off-by-one error actually originates, but > > this narrows down the problem a lot. > > The Y-coordinate error may be less than one. Most of the DRI hardware > drivers need X/Y coordinates biased by a small amount in order to make > hardware rasterization and software rasterization coincide. > > So, something like 0.75 or 0.875 might work better.
Yeah, I just realized that. I'm playing with X and Y subpixel offsets to try and find a combination that fixes the most problems without breaking tests that worked. :) -- Leif Delgass http://www.retinalburn.net ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek PC Mods, Computing goodies, cases & more http://thinkgeek.com/sf _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
