Paul Berry
fffba41c68
Previously, we gave all of the URB space (other than the small amount that is used for push constants) to the vertex shader. However, when a geometry shader is active, we need to divide it up between the vertex and geometry shaders. The size of the URB entries for the vertex and geometry shaders can vary dramatically from one shader to the next. So it doesn't make sense to simply split the available space in two. In particular: - On Ivy Bridge GT1, this would not leave enough space for the worst case geometry shader, which requires 64k of URB space. - Due to hardware-imposed limits on the maximum number of URB entries, sometimes a given shader stage will only be capable of using a small amount of URB space. When this happens, it may make sense to allocate substantially less than half of the available space to that stage. Our algorithm for dividing space between the two stages is to first compute (a) the minimum amount of URB space that each stage needs in order to function properly, and (b) the amount of additional URB space that each stage "wants" (i.e. that it would be capable of making use of). If the total amount of space available is not enough to satisfy needs + wants, then each stage's "wants" amount is scaled back by the same factor in order to fit. When only a vertex shader is active, this algorithm produces equivalent results to the old algorithm (if the vertex shader stage can make use of all the available URB space, we assign all the space to it; if it can't, we let it use as much as it can). In the future, when we need to support tessellation control and tessellation evaluation pipeline stages, it should be straightforward to expand this algorithm to cover them. v2: Use "unsigned" rather than "GLuint". Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
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 osmesa mesagdi to build classic mesa Windows GDI drivers; or 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. 1) install python 2.7 2) install scons (latest) 3) install mingw, flex, and bison 4) install libxml2 from here: http://www.lfd.uci.edu/~gohlke/pythonlibs get libxml2-python-2.9.1.win-amd64-py2.7.exe 5) install pywin32 from here: http://www.lfd.uci.edu/~gohlke/pythonlibs get pywin32-218.4.win-amd64-py2.7.exe 6) install git 7) download mesa from git see http://www.mesa3d.org/repository.html 8) 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.