|Summary:||wrong addresses (?) for 3D drawing : clipping or what ?|
|Product:||Mesa||Reporter:||Pierre Nerzic <pierre.nerzic>|
|Component:||Drivers/DRI/Unichrome||Assignee:||Default DRI bug account <dri-devel>|
|Status:||RESOLVED MOVED||QA Contact:|
|i915 platform:||i915 features:|
Description Pierre Nerzic 2007-05-16 05:57:37 UTC
I own a VIA EPIA800ML, with unichrome graphic adapter. I am using Ubuntu 7.04 with mesa 6.5.2. Dri is installed and works. The problem appears when using blender or winehq with 3D OpenGL software : there seems to be an address (offset ???) wrong calculation or clipping when positionning the 3D window on the screen. Let me explain with ascii graphics : The big rectangle is the screen, the small one inside is a 3D window. The application tries to draw something inside the window, I can only see the part marked with V. The right and bottom part stays blank. +-----------------------------+ |xxxxxxxxxx | |xxxx+--------+ | |xxxx|VVVVV | | |xxxx|VVVVV | | | | | | | +--------+ | | | +-----------------------------+ The 3D scene should be fully visible inside the window BUT seems to be clipped by the area marked xxx, which has the same size than the window. So I can only see the part marked VVV - but its origins is correctly in the upper left corner of the window : it is not drawn in the screen coordinates. When I move the window, the clipping area stays in (0,0), masking a larger amount if I move to the right or bottom. The only way to see the full 3D view is to move the window at screen(0,0). There is also a same problem with the menus, for instance in blender. Every menu or widget appears corrupt or blank. I suspect the same problem : the menu would be cleanly displayed only if at screen(0,0) (?). Is this a problem with the stencil buffer, the clipping area, the hardware driver ? I was thinking of the hardware because : 1) there is generally a lot of noisy pixels around the 3D area : the border of the window is very dirty, with random lines and pixel patterns (there is no segmentation failure). 2) the mouse cursor (image) is draw very badly : I can see a white square around the previous position in the menus Very surprisingly, there is no problem with glxgears : I can move its window without any problem (560 fps). Does it use stencils or scissors ? I would be very interested to help in finding this bug, but I can find no explanations on the internals of mesa and dri/drm. Many thanks for all, Pierre pierre.nerzic domain free.fr (replace domain by at)
Comment 1 Alex Deucher 2007-05-16 06:02:53 UTC
You might try a newer mesa or mesa from git. IIRC, there were some via fixes for similar sounding problems.
Comment 2 GitLab Migration User 2019-09-18 20:34:45 UTC
-- GitLab Migration Automatic Message -- This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity. You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/openchrome/old-bug-database/issues/3.