From: Alexander Larsson <al...@redhat.com> I tracked down the power point 2007 scrollbar rendering issue today. Its caused by the scaling in pixman. When drawing the scrollbar ppt renders a 16x1 region of a larger image to the destination rect of the whole scrollbar. I.e. it will be scaling the 16x1 region to something like 16x481 (or whatever the height of the scrollbar is).
The problem is that we got the coordinates wrong when calculating the scaling in pixman, so we picked the row above the scrollbar theme region instead hitting something completely different (solid green). The core of the problem is that with pixman, when doing scaling we specify the source coordinates not in the source image coordinate system, but in the transformed space, meaning that the coordinate conversion is not trivial (which you might otherwise assume, since we're copying an integer rect area to another integer rect area). The actual scaling factor handed to pixman is a 16.16 fixed point value. This may be off by a bit from the real scaling factor, and we used to use the real (double) scaling factor to calculate the transformed source coordinates, which didn't match what pixman then did. The patch fixes this by doing the calculations in fixed point. However, there seems to be second issue causing tall enough scrollbars to become black at the bottom. This seems to be a related issue where the scaling factor makes pixman step past the 16x1 region into the row below that. However, I can't for the life of me figure out why this is happening. I think need some help from soeren here... Alexander Larsson (1): canvas: Better coordinate rounding in scaling common/sw_canvas.c | 64 +++++++++++++++++++++++++++++---------------------- 1 files changed, 36 insertions(+), 28 deletions(-) -- 1.7.2.1 _______________________________________________ Spice-devel mailing list Spice-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/spice-devel
