diff options
Diffstat (limited to 'doxygen/gallium.doc')
| -rw-r--r-- | doxygen/gallium.doc | 199 |
1 files changed, 191 insertions, 8 deletions
diff --git a/doxygen/gallium.doc b/doxygen/gallium.doc index 5fe04ba..de39573 100644 --- a/doxygen/gallium.doc +++ b/doxygen/gallium.doc @@ -1,17 +1,200 @@ /** \mainpage -\sa http://www.tungstengraphics.com/wiki/index.php/Gallium3D -\sa \ref glxgears + \section about About + + Gallium3D is <a href="http://www.tungstengraphics.com/">Tungsten Graphics</a>' + new architecture for building 3D graphics drivers. Initially + supporting Mesa and Linux graphics drivers, Gallium3D is designed to allow + portability to all major operating systems and graphics interfaces. + + Compared to existing Linux graphics drivers, Gallium3D will: + + - Make drivers smaller and simpler. + Current DRI drivers are rather complicated. They're large, contain + duplicated code and are burdened with implementing many concepts tightly + tied to the OpenGL 1.x/2.x API. + + - Model modern graphics hardware. + The new driver architecture is an abstraction of modern graphics hardware, + rather than an OpenGL->hardware translator. The new driver interface will + assume the presence of programmable vertex/fragment shaders and flexible + memory objects. + + - Support multiple graphics APIs. + The OpenGL 3.0 API will be very different from OpenGL 1.x/2.x. We'd like a + driver model that is API-neutral so that it's not tied to a specific + graphics API. + + \section contents Contents + + - \ref overview + + - \ref statetracker + + - Pipe drivers: + - \ref softpipe + - \ref i915simple + - \ref failover + - Cell driver (cell_context.h, cell_winsys.h) + + - Winsys drivers: + - X11 winsys driver (xm_winsys.c) + - Intel DRI winsys driver (intel_context.h, intel_winsys_pipe.c) + + - Ancillary Modules: + - \ref draw + - \ref tgsi + - LLVM TGSI backend (gallivm.h) + + - \ref callgraph + + \section external External documentation + + - <a href="http://www.tungstengraphics.com/gallium3D.htm">Gallium3D's Architectural Overview</a> + - <a href="http://www.tungstengraphics.com/wiki/index.php/Gallium3D">Technical Overview</a> + - <a href="http://www.tungstengraphics.com/wiki/files/gallium3d-xds2007.pdf">Gallium3D talk from XDS 2007</a> */ -/** \page glxgears glxgears example +/** \page overview Overview + + The public interface of a Gallium3D driver is described by the p_context.h + header file. The pipe_context structure is an abstract base class with + methods for: + + - Setting rendering state (texture sampler state, vertex array info, drawing surfaces, etc.) + + - Setting shader state, using the TGSI binary shader representation. + + - Vertex array and indexed vertex array drawing. + + - Region (memory) management for textures, renderbuffers, vertex buffers, etc. + + - Hardware queries (number of texture units, max texture size, etc). + + The p_state.h header defines all the state objects (such as polygon + rasterization options, blend modes, etc) and resources (drawing surfaces, + textures, memory buffers). The pipe interface uses "constant state" objects. + That is, state objects are created once and are immutable. State objects are + put into effect by binding them. This allows Gallium3D drivers to create + corresponding hardware state objects which can be quickly handled. + + The p_defines.h header defines numerous constants and tokens (blend modes, + texture wrap modes, surface formats, etc. + + The p_winsys.h header defines the window system and OS facilities which + Gallium3D drivers rely upon. For example, memory allocation is typically a + service the OS provides while window size/position information is provided by + the window system. Pipe drivers use the winsys interface to handle these + things. + + By abstracting OS and window system services, pipe drivers are portable to + other platforms (e.g. embedded devices). +*/ + +/** \page statetracker The State Tracker + + The state tracker is the piece which interfaces core Mesa to the Gallium3D + interface. It's responsible for translating Mesa state (blend modes, texture + state, etc) and drawing commands (like glDrawArrays and glDrawPixels) into + pipe objects and operations. + + Traditional fixed-function OpenGL components (such as lighting and texture + combining) are implemented with shaders. OpenGL commands such as glDrawPixels + are translated into textured quadrilateral rendering. Basically, any + rendering operation that isn't directly supported by modern graphics hardware + is translated into a hardware-friendly form. - Profile of the glxgears application with the Gallium3D's softpipe reference driver. + Future state trackers will be created for OpenGL 3.0 and OpenGL-ES 2.x. +*/ + +/** \page softpipe Softpipe Driver + + The softpipe driver is a software implementation of the Gallium3D interface. + It will be used as a reference implementation and as a fallback driver when a + hardware driver isn't available. The softpipe driver will make extensive use + of run-time code generation to efficiently execute vertex, fragment and + rasterization operations. - The functions in the graph below are clickable (in the HTML output). + \sa sp_winsys.h +*/ + +/** \page i915simple Simple i915 Driver + + The i915 Gallium3D Driver is an initial hardware driver implementation within + the Gallium3D driver architecture. We expect that once complete this driver + will have equivalent functionality and performance to the current Mesa + i915tex driver, but from a much smaller codebase. + + \sa i915_winsys.h +*/ + +/** \page failover Failover Module + + The failover module acts as a selector between a hardware driver and the + softpipe driver. When the hardware can't implement a particular rendering + operation, the failover module will pass the request to the softpipe driver. + This is a different solution to the "software fallbacks" scheme of previous + Mesa drivers. + + \sa fo_winsys.h +*/ + +/** \page draw Draw Module + The Draw module provides point/line/polygon rendering services such as + vertex transformation, polygon culling and clipping. It will be used by + drivers for hardware which lacks vertex transformation (such as the + i915/i945). It may also be instantiated and used directly by the state + tracker to implement some API functionality that doesn't map well to hardware + capabilities. + + The interface of this module corresponds closely to the subset of the Gallium + Driver Interface which is relevent to these steps in the pipeline. Specifically + there are calls for: + + - Vertex shader constant state objects + - Vertex buffer binding + - Vertex element layout (vertex fetch) constant state objects + - DrawArrays and DrawElements + - Rasterizer constant state objects. + + The Draw module is effectively the part of \ref softpipe which is concerned with + vertex processing, split off into a separate module so that it can be reused + by drivers for rasterization-only hardware. As such it is also instantiated + by the \ref i915simple driver. + + Additionally, there are cases in the Mesa OpenGL state_tracker where it is + required to obtain transformed vertices and yet it is anticipated that using + hardware transformation even if available would reduce performance, usually + because the setup costs or latency are prohibitive. For this reason the Mesa + state_tracker also instantiates a copy of this module. + + \sa draw_context.h +*/ + +/** \page tgsi TGSI + + The TGSI module provides a universal representation of shaders and + CPU-based execution of shaders. All Mesa vertex/fragment programs and shaders + are translated into the TGSI representation before being passed to the + driver. In turn, the driver will convert the TGSI instructions into + GPU-specific instructions. For hardware that lacks vertex or fragment shader + support, the TGSI's executor can be used. The TGSI executor includes support + for SSE code generation. Support for other processors (such as Cell) will be + added in the future. + + \sa tgsi_parse.h + \sa <a href="http://www.tungstengraphics.com/wiki/files/tgsi.pdf">TGSI specification</a> +*/ + +/** \page callgraph Glxgears callgraph example + + Below is a call graph of the glxgears application together with the Gallium3D's softpipe reference driver. + + \htmlonly + The functions in the graph below are clickable. + \endhtmlonly - Please from the top right of this page: =============================> \dot digraph { graph [fontname=Arial, fontsize=10]; @@ -134,5 +317,5 @@ digraph { \enddot - \sa http://code.google.com/p/jrfonseca/wiki/Gprof2Dot - */ + The graph above was generated by the <a href="http://code.google.com/p/jrfonseca/wiki/Gprof2Dot">gprof2dot.py script</a>. +*/ |