Mesa Introduction

# Introduction

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interactive 3D graphics.

A variety of device drivers allows Mesa to be used in many different environments ranging from software emulation to complete hardware acceleration for modern GPUs.

Mesa ties into several other open-source projects: the Direct Rendering Infrastructure and X.org to provide OpenGL support to users of X on Linux, FreeBSD and other operating systems.

# Project History

The Mesa project was originally started by Brian Paul. Here's a short history of the project.

August, 1993: I begin working on Mesa in my spare time. The project has no name at that point. I was simply interested in writing a simple 3D graphics library that used the then-new OpenGL API. I was partially inspired by the VOGL library which emulated a subset of IRIS GL. I had been programming with IRIS GL since 1991.

November 1994: I contact SGI to ask permission to distribute my OpenGL-like graphics library on the internet. SGI was generally receptive to the idea and after negotiations with SGI's legal department, I get permission to release it.

February 1995: Mesa 1.0 is released on the internet. I expected that a few people would be interested in it, but not thousands. I was soon receiving patches, new features and thank-you notes on a daily basis. That encouraged me to continue working on Mesa. The name Mesa just popped into my head one day. SGI had asked me not to use the terms "Open" or "GL" in the project name and I didn't want to make up a new acronym. Later, I heard of the Mesa programming language and the Mesa spreadsheet for NeXTStep.

In the early days, OpenGL wasn't available on too many systems. It even took a while for SGI to support it across their product line. Mesa filled a big hole during that time. For a lot of people, Mesa was their first introduction to OpenGL. I think SGI recognized that Mesa actually helped to promote the OpenGL API, so they didn't feel threatened by the project.

1995-1996: I continue working on Mesa both during my spare time and during my work hours at the Space Science and Engineering Center at the University of Wisconsin in Madison. My supervisor, Bill Hibbard, lets me do this because Mesa is now being using for the Vis5D project.

October 1996: Mesa 2.0 is released. It implements the OpenGL 1.1 specification.

March 1997: Mesa 2.2 is released. It supports the new 3dfx Voodoo graphics card via the Glide library. It's the first really popular hardware OpenGL implementation for Linux.

September 1998: Mesa 3.0 is released. It's the first publicly-available implementation of the OpenGL 1.2 API.

March 1999: I attend my first OpenGL ARB meeting. I contribute to the development of several official OpenGL extensions over the years.

September 1999: I'm hired by Precision Insight, Inc. Mesa is a key component of 3D hardware acceleration in the new DRI project for XFree86. Drivers for 3dfx, 3dLabs, Intel, Matrox and ATI hardware soon follow.

October 2001: Mesa 4.0 is released. It implements the OpenGL 1.3 specification.

November 2001: I cofound Tungsten Graphics, Inc. with Keith Whitwell, Jens Owen, David Dawes and Frank LaMonica. I continue to develop Mesa as part of my resposibilities with Tungsten Graphics and as a spare-time project.

November 2002: Mesa 5.0 is released. It implements the OpenGL 1.4 specification.

January 2003: Mesa 6.0 is released. It implements the OpenGL 1.5 specification as well as the GL_ARB_vertex_program and GL_ARB_fragment_program extensions.

June 2007: Mesa 7.0 is released, implementing the OpenGL 2.1 specification and OpenGL Shading Language.

Ongoing: Mesa is used as the core of many hardware OpenGL drivers for the XFree86 and X.org X servers within the DRI project. I continue to enhance Mesa with new extensions and features.

# Major Versions

This is a summary of the major versions of Mesa. Mesa's major version number has been incremented whenever a new version of the OpenGL specification is implemented.

## Version 7.x features

Version 7.x of Mesa implements the OpenGL 2.1 API. The main feature of OpenGL 2.x is the OpenGL Shading Language.

## Version 6.x features

Version 6.x of Mesa implements the OpenGL 1.5 API with the following extensions incorporated as standard features:

- GL_ARB_occlusion_query
- GL_ARB_vertex_buffer_object
- GL_EXT_shadow_funcs

Also note that several OpenGL tokens were renamed in OpenGL 1.5 for the sake of consistency. The old tokens are still available.

    New Token                   Old Token
    ------------------------------------------------------------
    GL_FOG_COORD_SRC            GL_FOG_COORDINATE_SOURCE
    GL_FOG_COORD                GL_FOG_COORDINATE
    GL_CURRENT_FOG_COORD        GL_CURRENT_FOG_COORDINATE
    GL_FOG_COORD_ARRAY_TYPE     GL_FOG_COORDINATE_ARRAY_TYPE
    GL_FOG_COORD_ARRAY_STRIDE   GL_FOG_COORDINATE_ARRAY_STRIDE
    GL_FOG_COORD_ARRAY_POINTER  GL_FOG_COORDINATE_ARRAY_POINTER
    GL_FOG_COORD_ARRAY          GL_FOG_COORDINATE_ARRAY
    GL_SRC0_RGB                 GL_SOURCE0_RGB
    GL_SRC1_RGB                 GL_SOURCE1_RGB
    GL_SRC2_RGB                 GL_SOURCE2_RGB
    GL_SRC0_ALPHA               GL_SOURCE0_ALPHA
    GL_SRC1_ALPHA               GL_SOURCE1_ALPHA
    GL_SRC2_ALPHA               GL_SOURCE2_ALPHA

See the OpenGL specification for more details.

## Version 5.x features

Version 5.x of Mesa implements the OpenGL 1.4 API with the following extensions incorporated as standard features:

- GL_ARB_depth_texture
- GL_ARB_shadow
- GL_ARB_texture_env_crossbar
- GL_ARB_texture_mirror_repeat
- GL_ARB_window_pos
- GL_EXT_blend_color
- GL_EXT_blend_func_separate
- GL_EXT_blend_logic_op
- GL_EXT_blend_minmax
- GL_EXT_blend_subtract
- GL_EXT_fog_coord
- GL_EXT_multi_draw_arrays
- GL_EXT_point_parameters
- GL_EXT_secondary_color
- GL_EXT_stencil_wrap
- GL_EXT_texture_lod_bias (plus, a per-texture LOD bias parameter)
- GL_SGIS_generate_mipmap

## Version 4.x features

Version 4.x of Mesa implements the OpenGL 1.3 API with the following extensions incorporated as standard features:

- GL_ARB_multisample
- GL_ARB_multitexture
- GL_ARB_texture_border_clamp
- GL_ARB_texture_compression
- GL_ARB_texture_cube_map
- GL_ARB_texture_env_add
- GL_ARB_texture_env_combine
- GL_ARB_texture_env_dot3
- GL_ARB_transpose_matrix

## Version 3.x features

Version 3.x of Mesa implements the OpenGL 1.2 API with the following features:

- BGR, BGRA and packed pixel formats
- New texture border clamp mode
- glDrawRangeElements()
- standard 3-D texturing
- advanced MIPMAP control
- separate specular color interpolation

## Version 2.x features

Version 2.x of Mesa implements the OpenGL 1.1 API with the following features.

- Texture mapping:
  - glAreTexturesResident
  - glBindTexture
  - glCopyTexImage1D
  - glCopyTexImage2D
  - glCopyTexSubImage1D
  - glCopyTexSubImage2D
  - glDeleteTextures
  - glGenTextures
  - glIsTexture
  - glPrioritizeTextures
  - glTexSubImage1D
  - glTexSubImage2D
- Vertex Arrays:
  - glArrayElement
  - glColorPointer
  - glDrawElements
  - glEdgeFlagPointer
  - glIndexPointer
  - glInterleavedArrays
  - glNormalPointer
  - glTexCoordPointer
  - glVertexPointer
- Client state management:
  - glDisableClientState
  - glEnableClientState
  - glPopClientAttrib
  - glPushClientAttrib
- Misc:
  - glGetPointer
  - glIndexub
  - glIndexubv
  - glPolygonOffset