Topi Pohjolainen
0dcd9a09d1
Part of brw_try_draw_prims() is a check to validate textures
(brw_validate_textures()). In case of textures that currently have
only level zero but are marked for mipmap generation, i965 driver
will decide to replace the underlying buffer with a larger one
capable of holding also the additional levels. This results into
blit from the original buffer to the newly allocated (see
intel_miptree_copy_teximage()). This blit is currently handled with
blitter engine and hence it won't effect the ongoing draw operation.
However, this blit in turn may trigger color resolve on the source
buffer. In principle, this should be possible with fast cleared
buffers but I only started hitting it when I enabled lossless
compression (that reguires similar resolve to fast cleared buffers).
Now, the color resolve is a meta operation and uses the same drawing
path we are already in middle of. After quite a bit of debugging I
realized that the resolve will modify the current vbo setup but it
won't restore it afterwards resulting in the original draw call
using wrong vertex data.
When brw_try_draw_prims() gets called, the vbo logic in the Mesa
core (see vbo_draw_arrays()) has just bound the vbo (see
vbo_bind_arrays() and recalculate_input_bindings()). Color resolve
operation will overwrite the vbo setup by calling vbo_bind_arrays()
against the resolve rectangle (see brw_draw_rectlist()). Once the
color resolve is done the vbo setup is left to the resolve rectangle
state and the original drawing call yields bogus results.
This patch aims to restore the original state after the color
resolve by calling vbo_bind_arrays() yet again after the vertex
array state in the core context have been restored.
Now having said all this, I'd also like to state that I'm quite
uncomfortable with the nested meta operations. Ths original draw
call in this case is in fact a meta operation itself. It is a blit
from level zero to level one when generating the additional mipmap
levels (see _mesa_meta_GenerateMipmap()). Imagine the complexity
if the blit in the middle from buffer to another would go to meta
path also instead of blitter.
I would very tempted to try to move all the resolves to happen
before a meta operation is started.
Additionally I still feel that work I did earlier in the spring/
summer time moving meta operations to use direct state upload
bypassing the core context would make sense.
v2: Force input recalculation by setting the flag explicitly
v3: Do not attempt to restore vbo for opengles1 which doesn't
support vertex buffer objects.
Signed-off-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
File: docs/README.WIN32 Last updated: 21 June 2013 Quick Start ----- ----- Windows drivers are build with SCons. Makefiles or Visual Studio projects are no longer shipped or supported. Run scons libgl-gdi to build gallium based GDI driver. This will work both with MSVS or Mingw. Windows Drivers ------- ------- At this time, only the gallium GDI driver is known to work. Source code also exists in the tree for other drivers in src/mesa/drivers/windows, but the status of this code is unknown. Recipe ------ Building on windows requires several open-source packages. These are steps that work as of this writing. - install python 2.7 - install scons (latest) - install mingw, flex, and bison - install pywin32 from here: http://www.lfd.uci.edu/~gohlke/pythonlibs get pywin32-218.4.win-amd64-py2.7.exe - install git - download mesa from git see http://www.mesa3d.org/repository.html - run scons General ------- After building, you can copy the above DLL files to a place in your PATH such as $SystemRoot/SYSTEM32. If you don't like putting things in a system directory, place them in the same directory as the executable(s). Be careful about accidentially overwriting files of the same name in the SYSTEM32 directory. The DLL files are built so that the external entry points use the stdcall calling convention. Static LIB files are not built. The LIB files that are built with are the linker import files associated with the DLL files. The si-glu sources are used to build the GLU libs. This was done mainly to get the better tessellator code. If you have a Windows-related build problem or question, please post to the mesa-dev or mesa-users list.