This patch series lays the groundwork for the i965 geometry shader back-end by separating the functions and data structures which are specific to vertex shaders from those that can also be used to compile geometry shaders. (Following a naming convention that is already present in the codebase, this common code is referred to as "vec4" code, since in the future we should be able to use it for any shader stage where the hardware expects a pair of vec4s to be stored in each register. This includes tessellation control and tessellation evaluation shaders.)
In particular, the following structs/classes have been split into a base class containing vec4-generic data, and a derived class containing VS-specific data: - brw_vs_compile (new base struct is brw_vec4_compile) - brw_vs_prog_key (new base struct is brw_vec4_prog_key) - brw_vs_prog_data (new base struct is brw_vec4_prog_data) - vec4_visitor (new derived class is vec4_vs_visitor) In the case of vec4_visitor, standard C++ inheritance is used, and VS-specific behaviours are moved into virtual functions. The other three cases use C-style inheritance (the derived struct has an explicit "base" element, and there are no virtual functions), since these structs need to be accessible from plain C code. In addition, small modifications have been made to the vec4_generator class and the brw_compute_vue_map() function to generalize them for use by both vertex and geometry shaders. To keep merge conflicts to a minimum (since this patch series has been in development for several weeks), I've tried to minimize the amount of code motion introduced by this change. As a result, the patch series leaves vec4_vs_visitor functions scattered in several files (brw_vec4.cpp, brw_vec4_visitor.cpp, and brw_vec4_vp.cpp). Once this series lands, I'd like to follow up with a patch series that moves all of the vec4_vs_visitor functions to a new brw_vec4_vs_visitor.cpp file, and moves the class declaration to a corresponding header. I'll wait until this patch series has landed before starting on that, and try not to do it while anyone is in the middle of major VS back-end work. Note that this patch series must be applied atop the patch "i965/vs: Fix DEBUG_SHADER_TIME when VS terminates with 2 URB writes", which I sent out for review this morning. You can find the complete series in context at branch "gs-backend-prep" of git://github.com/stereotype441/mesa.git. In order to verify that it's actually possible to build geometry shader functionality atop these changes, I have begun prototyping an implementation of geometry shaders which passes all existing geometry shader Piglit tests. (Sadly, there are many more tests left to write, and features left to implement!) I'll be sending out those patches in the coming month(s), as they mature. You can find that series in branch "gs" of git://github.com/stereotype441/mesa.git. Note that the "gs" branch is *highly volatile*, so if you want to base work on it, please let me know so we can coordinate. Piglit-tested on i965/Gen7--no regressions. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
