docs/RELNOTES-3.3

   1
   2                          Mesa 3.3 release notes
   3
   4                              PLEASE READ!!!!
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   6
   7
   8
   9 Header file / GLenum changes
  10 ----------------------------
  11
  12 The gl.h and glu.h headers now use #defines to define all GL_* tokens
  13 instead of C-language enums.  This change improves Mesa/OpenGL
  14 interoperability.
  15
  16
  17
  18 New API dispatch code
  19 ---------------------
  20
  21 The core Mesa gl* functions are now implemented with a new dispatch
  22 (jump table) which will allow simultaneous direct/indirect rendering.
  23
  24 The code is found in the glapi*.[ch] files.
  25
  26 Of interest:  the actual "glFooBar" functions are generated with
  27 templatized code defined in glapitemp.h and included by glapi.c
  28 The glapitemp.h template should be reusable for all sorts of OpenGL
  29 projects.
  30
  31
  32 New thread support
  33 ------------------
  34
  35 Thread support in Mesa has been rewritten.  The glthread.[ch] files
  36 replace mthreads.[ch].  Thread safety is always enabled (on platforms
  37 which support threads, that is).  There is virtually no performance
  38 penalty for typical single-thread applications.  See the glapi.c
  39 file for details.
  40
  41
  42
  43 Make configuration changes
  44 --------------------------
  45
  46 If you use the old-style (non GNU automake) method to build Mesa note
  47 that several of the configuration names have changed:
  48
  49    Old name        New name
  50    -------------   ----------------
  51    linux-elf       linux
  52    linux           linux-static
  53    linux-386-elf   linux-386
  54    linux-386       linux-386-static
  55    etc.
  56
  57
  58
  59 New extensions
  60 --------------
  61
  62 GL_EXT_transpose_matrix
  63         Adds glLoadTransposeMatrix() and glMultTransposeMatrix() functions.
  64         See http://reality.sgi.com/opengl/arb/extensions/ext_text/GL_EXT_transpose_matrix.txt
  65
  66 GL_EXT_texture_add_env
  67         Adds GL_ADD texture environment mode.
  68         See http://www.berkelium.com/OpenGL/EXT/texture_env_add.txt
  69
  70 GL_EXT_texture_lod_bias
  71         Allows mipmapped texture blurring and sharpening.
  72
  73 GLX_EXT_visual_rating extension
  74         This extension has no effect in stand-alone Mesa (used for DRI).
  75
  76 GL_HP_occlusion_test
  77         Used for bounding box occlusion testing (see demos/occlude.c).
  78
  79 GL_SGIX_pixel_texture / GL_SGIS_pixel_texture
  80         Lets glDraw/CopyPixels draw a texture coordinate image.
  81
  82 GL_SGI_color_matrix
  83         Adds a color matrix and another set of scale and bias parameters
  84         to the glDraw/CopyPixels paths.
  85
  86
  87 GLX_SGI_make_current_read functionality
  88 ---------------------------------------
  89
  90 The functionality of this extension is needed for GLX 1.3 (and required
  91 for the Linux/OpenGL standards base).
  92
  93 Implementing this function required a **DEVICE DRIVER CHANGE**.
  94 The old SetBuffer() function has been replaced by SetReadBuffer() and
  95 SetDrawBuffer().  All device drivers will have to be updated because
  96 of this change.
  97
  98 The new function, glXMakeContextCurrent(), in GLX 1.3 now works in Mesa.
  99 The xdemos/wincopy.c program demonstrates it.
 100
 101
 102
 103 Image-related code changes
 104 --------------------------
 105
 106 The imaging path code used by glDrawPixels, glTexImage[123]D,
 107 glTexSubImage[123], etc has been rewritten.  It's now faster,
 108 uses less memory and has several bug fixes.  This work was
 109 actually started in Mesa 3.1 with the glTexImage paths but has now
 110 been carried over to glDrawPixels as well.
 111
 112
 113
 114 Device driver interface changes
 115 -------------------------------
 116
 117 Added new functions for hardware stencil buffer support:
 118    WriteStencilSpan
 119    ReadStencilSpan
 120    WriteStencilPixels
 121    ReadStencilPixels
 122
 123
 124 Removed old depth buffer functions:
 125    AllocDepthBuffer
 126    DepthTestSpan
 127    DepthTestPixels
 128    ReadDepthSpanFloat
 129    ReadDepthSpanInt
 130
 131
 132 Added new depth buffer functions:
 133    WriteDepthSpan
 134    ReadDepthSpan
 135    WriteDepthPixels
 136    ReadDepthPixels
 137
 138    These functions always read/write 32-bit GLuints.  This will allow
 139    drivers to have anywhere from 0 to 32-bit Z buffers without
 140    recompiling for 16 vs 32 bits as was previously needed.
 141
 142
 143 New texture image functions
 144    The entire interface for texture image specification has been updated.
 145    With the new functions, it's optional for Mesa to keep an internal copy
 146    of all textures.  Texture download should be a lot faster when the extra
 147    copy isn't made.
 148
 149 Misc changes
 150    TexEnv now takes a target argument
 151    Removed UseGlobalTexturePalette (use Enable function instead)
 152
 153
 154 Also added
 155    ReadPixels
 156    CopyPixels
 157
 158
 159 The SetBufffer function has been replaced by SetDrawBuffer and
 160 SetReadBuffer functions.  This lets core Mesa independently
 161 specify which buffer is to be used for reading and which for
 162 drawing.
 163
 164 The Clear function's mask parameter has changed.  Instead of
 165 mask being the flags specified by the user to glClear, the
 166 mask is now a bitmask of the DD_*_BIT flags in dd.h.  Now
 167 multiple color buffers can be specified for clearing (ala
 168 glDrawBuffers).  The driver's Clear function must also
 169 check the glColorMask glIndexMask, and glStencilMask settings
 170 and do the right thing.  See the X/Mesa, OS/Mesa, or FX/Mesa
 171 drivers for examples.
 172
 173
 174 The depth buffer changes shouldn't be hard to make for existing
 175 drivers.  In fact, it should simply the code.  Be careful with
 176 the depthBits value passed to gl_create_context().  1 is a bad
 177 value!  It should normally be 0, 16, 24, or 32.
 178
 179
 180 gl_create_framebuffer() takes new arguments which explicitly tell
 181 core Mesa which ancillary buffers (depth, stencil, accum, alpha)
 182 should be implemented in software.  Mesa hardware drivers should
 183 carefully set these flags depending on which buffers are in the
 184 graphics card.
 185
 186
 187
 188 Internal constants
 189 ------------------
 190
 191 Point and line size range and granularity limits are now stored
 192 in the gl_constants struct, which is the Const member of GLcontext.
 193 The limits are initialized from values in config.h but may be
 194 overridden by device drivers to reflect the limits of that driver's
 195 hardware.
 196
 197 Also added constants for NumAuxBuffers and SubPixelBits.
 198
 199
 200
 201
 202 ----------------------------------------------------------------------
 203 $Id: RELNOTES-3.3,v 1.2 2000/04/08 18:58:05 brianp Exp $