Mesa source code tree overview
==============================

This is a brief summary of Mesa's directory tree and what's contained in
each directory.

-  **docs** - Documentation
-  **include** - Public OpenGL header files
-  **src**

   -  **compiler** - Common utility sources for different compilers.

      -  **glsl** - the GLSL IR and compiler
      -  **nir** - the NIR IR and compiler
      -  **spirv** - the SPIR-V compiler

   -  **egl** - EGL library sources

      -  **drivers** - EGL drivers
      -  **main** - main EGL library implementation. This is where all
         the EGL API functions are implemented, like ``eglCreateContext()``.

   -  **mapi** - Mesa APIs
   -  **glapi** - OpenGL API dispatch layer. This is where all the GL
      entrypoints like ``glClear``, ``glBegin``, etc. are generated, as well as
      the GL dispatch table. All GL function calls jump through the
      dispatch table to functions found in main/.
   -  **mesa** - Main Mesa sources

      -  **main** - The core Mesa code (mainly state management)
      -  **drivers** - Mesa drivers (not used with Gallium)

         -  **common** - code which may be shared by all drivers
         -  **dri** - Direct Rendering Infrastructure drivers

            -  **common** - code shared by all DRI drivers
            -  **i915** - driver for Intel i915/i945
            -  **i965** - driver for Intel i965
            -  **radeon** - driver for ATI R100
            -  **r200** - driver for ATI R200
            -  XXX more

         -  **x11** - Xlib-based software driver
         -  **osmesa** - off-screen software driver
         -  XXX more

      -  **math** - vertex array translation and transformation code
         (not used with Gallium)
      -  **program** - Vertex/fragment shader and GLSL compiler code
      -  **sparc** - Assembly code/optimizations for SPARC systems (not
         used with Gallium)
      -  **state\_tracker** - State tracker / driver for Gallium. This
         is basically a Mesa device driver that speaks to Gallium. This
         directory may be moved to src/mesa/drivers/gallium at some
         point.
      -  **swrast** - Software rasterization module. For drawing points,
         lines, triangles, bitmaps, images, etc. in software. (not used
         with Gallium)
      -  **swrast\_setup** - Software primitive setup. Does things like
         polygon culling, ``glPolygonMode``, polygon offset, etc. (not used
         with Gallium)
      -  **tnl** - Software vertex Transformation 'n Lighting. (not used
         with Gallium)
      -  **tnl\_dd** - TNL code for device drivers. (not used with
         Gallium)
      -  **vbo** - Vertex Buffer Object code. All drawing with
         ``glBegin/glEnd``, ``glDrawArrays``, display lists, etc. goes through
         this module. The results is a well-defined set of vertex arrays
         which are passed to the device driver (or tnl module) for
         rendering.
      -  **x86** - Assembly code/optimizations for 32-bit x86 systems
         (not used with Gallium)
      -  **x86-64** - Assembly code/optimizations for 64-bit x86 systems
         (not used with Gallium)

   -  **gallium** - Gallium3D source code

      -  **include** - Gallium3D header files which define the Gallium3D
         interfaces
      -  **drivers** - Gallium3D device drivers

         -  **i915** - Driver for Intel i915/i945.
         -  **llvmpipe** - Software driver using LLVM for runtime code
            generation.
         -  **nouveau** - Driver for NVIDIA GPUs.
         -  **radeon** - Shared module for the r600 and radeonsi
            drivers.
         -  **radeonsi** - Driver for AMD Southern Island.
         -  **r300** - Driver for ATI R300 - R500.
         -  **r600** - Driver for ATI/AMD R600 - Northern Island.
         -  **softpipe** - Software reference driver.
         -  **svga** - Driver for VMware's SVGA virtual GPU.
         -  **trace** - Driver for tracing Gallium calls.
         -  XXX more

      -  **auxiliary** - Gallium support code

         -  **draw** - Software vertex processing and primitive assembly
            module. This includes vertex program execution, clipping,
            culling and optional stages for drawing wide lines, stippled
            lines, polygon stippling, two-sided lighting, etc. Intended
            for use by drivers for hardware that does not have vertex
            shaders. Geometry shaders will also be implemented in this
            module.
         -  **cso\_cache** - Constant State Objects Cache. Used to
            filter out redundant state changes between state trackers
            and drivers.
         -  **gallivm** - LLVM module for Gallium. For LLVM-based
            compilation, optimization and code generation for TGSI
            shaders. Incomplete.
         -  **pipebuffer** - utility module for managing buffers
         -  **rbug** - Gallium remote debug utility
         -  **rtasm** - run-time assembly/machine code generation.
            Currently there's run-time code generation for x86/SSE,
            PowerPC and Cell SPU.
         -  **tgsi** - TG Shader Infrastructure. Code for encoding,
            manipulating and interpreting GPU programs.
         -  **translate** - module for translating vertex data from one
            format to another.
         -  **util** - assorted utilities for arithmetic, hashing,
            surface creation, memory management, 2D blitting, simple
            rendering, etc.
         -  XXX more

      -  **state\_trackers** -

         -  **clover** - OpenCL state tracker
         -  **dri** - Meta state tracker for DRI drivers
         -  **glx** - Meta state tracker for GLX
         -  **wgl** - Windows WGL state tracker
         -  **xa** - XA state tracker
         -  **xvmc** - XvMC state tracker
         -  **vdpau** - VDPAU state tracker
         -  **va** - VA-API state tracker
         -  **omx\_bellagio** - OpenMAX Bellagio state tracker

      -  **winsys** -

         -  **drm** -
         -  **gdi** -
         -  **xlib** -

   -  **glx** - The GLX library code for building libGL using DRI
      drivers.

-  **lib** - hardlinks to most binaries as produced by ``make``. These
   (shortcuts) are used for development purposes in conjunction with
   ``LD_LIBRARY_PATH`` and/or ``LIBGL_DRIVERS_PATH``.