docs/RELNOTES-3.3

   1
   2                          Mesa 3.3 release notes
   3
   4                              PLEASE READ!!!!
   5
   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_ARB_transpose_matrix
  63         Adds glLoadTransposeMatrixARB() and glMultTransposeMatrixARB()
  64         functions.
  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 GL_SGI_color_table
  87         Adds additional color tables to the glDraw/Read/CopyPixels paths.
  88
  89 GL_EXT_histogram
  90         Compute histograms for glDraw/Read/CopyPixels.
  91
  92 GL_EXT_blend_func_separate
  93         This is the same as GL_INGR_blend_func_separate.
  94
  95 Documentation for all these functions can be found at
  96 http://oss.sgi.com/projects/ogl-sample/registry/
  97
  98
  99
 100 GLX_SGI_make_current_read functionality
 101 ---------------------------------------
 102
 103 The functionality of this extension is needed for GLX 1.3 (and required
 104 for the Linux/OpenGL standards base).
 105
 106 Implementing this function required a **DEVICE DRIVER CHANGE**.
 107 The old SetBuffer() function has been replaced by SetReadBuffer() and
 108 SetDrawBuffer().  All device drivers will have to be updated because
 109 of this change.
 110
 111 The new function, glXMakeContextCurrent(), in GLX 1.3 now works in Mesa.
 112 The xdemos/wincopy.c program demonstrates it.
 113
 114
 115
 116 Image-related code changes
 117 --------------------------
 118
 119 The imaging path code used by glDrawPixels, glTexImage[123]D,
 120 glTexSubImage[123], etc has been rewritten.  It's now faster,
 121 uses less memory and has several bug fixes.  This work was
 122 actually started in Mesa 3.1 with the glTexImage paths but has now
 123 been carried over to glDrawPixels as well.
 124
 125
 126
 127 Device driver interface changes
 128 -------------------------------
 129
 130 Added new functions for hardware stencil buffer support:
 131    WriteStencilSpan
 132    ReadStencilSpan
 133    WriteStencilPixels
 134    ReadStencilPixels
 135
 136
 137 Removed old depth buffer functions:
 138    AllocDepthBuffer
 139    DepthTestSpan
 140    DepthTestPixels
 141    ReadDepthSpanFloat
 142    ReadDepthSpanInt
 143
 144
 145 Added new depth buffer functions:
 146    WriteDepthSpan
 147    ReadDepthSpan
 148    WriteDepthPixels
 149    ReadDepthPixels
 150
 151    These functions always read/write 32-bit GLuints.  This will allow
 152    drivers to have anywhere from 0 to 32-bit Z buffers without
 153    recompiling for 16 vs 32 bits as was previously needed.
 154
 155
 156 New texture image functions
 157    The entire interface for texture image specification has been updated.
 158    With the new functions, it's optional for Mesa to keep an internal copy
 159    of all textures.  Texture download should be a lot faster when the extra
 160    copy isn't made.
 161
 162 Misc changes
 163    TexEnv now takes a target argument
 164    Removed UseGlobalTexturePalette (use Enable function instead)
 165
 166
 167 Also added
 168    ReadPixels
 169    CopyPixels
 170
 171
 172 The SetBufffer function has been replaced by SetDrawBuffer and
 173 SetReadBuffer functions.  This lets core Mesa independently
 174 specify which buffer is to be used for reading and which for
 175 drawing.
 176
 177 The Clear function's mask parameter has changed.  Instead of
 178 mask being the flags specified by the user to glClear, the
 179 mask is now a bitmask of the DD_*_BIT flags in dd.h.  Now
 180 multiple color buffers can be specified for clearing (ala
 181 glDrawBuffers).  The driver's Clear function must also
 182 check the glColorMask glIndexMask, and glStencilMask settings
 183 and do the right thing.  See the X/Mesa, OS/Mesa, or FX/Mesa
 184 drivers for examples.
 185
 186
 187 The depth buffer changes shouldn't be hard to make for existing
 188 drivers.  In fact, it should simply the code.  Be careful with
 189 the depthBits value passed to gl_create_context().  1 is a bad
 190 value!  It should normally be 0, 16, 24, or 32.
 191
 192
 193 gl_create_framebuffer() takes new arguments which explicitly tell
 194 core Mesa which ancillary buffers (depth, stencil, accum, alpha)
 195 should be implemented in software.  Mesa hardware drivers should
 196 carefully set these flags depending on which buffers are in the
 197 graphics card.
 198
 199
 200
 201 Internal constants
 202 ------------------
 203
 204 Point and line size range and granularity limits are now stored
 205 in the gl_constants struct, which is the Const member of GLcontext.
 206 The limits are initialized from values in config.h but may be
 207 overridden by device drivers to reflect the limits of that driver's
 208 hardware.
 209
 210 Also added constants for NumAuxBuffers and SubPixelBits.
 211
 212
 213
 214
 215 ----------------------------------------------------------------------
 216 $Id: RELNOTES-3.3,v 1.5 2000/05/22 18:47:29 brianp Exp $