docs/RELNOTES-3.3

   1
   2                          Mesa 3.3 release notes
   3
   4                              July 21, 2000
   5
   6                              PLEASE READ!!!!
   7
   8
   9
  10 Introduction
  11 ------------
  12
  13 Mesa uses an even/odd version number scheme like the Linux kernel.
  14 Odd numbered versions (such as 3.3) designate new developmental releases.
  15 Even numbered versions (such as 3.2.1) designate stable releases.
  16
  17 Mesa 3.3 has a undergone many internal changes since version 3.2
  18 and features a lot of new extensions.  3.3 is expected to be pretty
  19 stable, but perhaps not as stable as 3.2 which has been used by
  20 thousands of users over the past months.
  21
  22 Everyone is encouraged to try Mesa 3.3.  Bugs should be reported to
  23 the Mesa bug database on www.sourceforge.net.
  24
  25
  26
  27 Header file / GLenum changes
  28 ----------------------------
  29
  30 The gl.h and glu.h headers now use #defines to define all GL_* tokens
  31 instead of C-language enums.  This change improves Mesa/OpenGL
  32 interoperability.
  33
  34
  35
  36 New API dispatch code
  37 ---------------------
  38
  39 The core Mesa gl* functions are now implemented with a new dispatch
  40 (jump table) which will allow simultaneous direct/indirect rendering.
  41
  42 The code is found in the glapi*.[ch] files.
  43
  44 Of interest:  the actual "glFooBar" functions are generated with
  45 templatized code defined in glapitemp.h and included by glapi.c
  46 The glapitemp.h template should be reusable for all sorts of OpenGL
  47 projects.
  48
  49 The new dispatch code has also optimized with x86 assembly code.
  50 This optimization eliminates copying the function arguments during
  51 dispatch.
  52
  53
  54
  55 New thread support
  56 ------------------
  57
  58 Thread support in Mesa has been rewritten.  The glthread.[ch] files
  59 replace mthreads.[ch].  Thread safety is always enabled (on platforms
  60 which support threads, that is).  There is virtually no performance
  61 penalty for typical single-thread applications.  See the glapi.c
  62 file for details.
  63
  64 The Xlib driver (XMesa) is now thread-safe as well.  Be sure to
  65 call XInitThreads() in your app first.  See the xdemos/glthreads.c
  66 demo for an example.
  67
  68
  69
  70 Make configuration changes
  71 --------------------------
  72
  73 If you use the old-style (non GNU automake) method to build Mesa note
  74 that several of the configuration names have changed:
  75
  76    Old name        New name
  77    -------------   ----------------
  78    linux-elf       linux
  79    linux           linux-static
  80    linux-386-elf   linux-386
  81    linux-386       linux-386-static
  82    etc.
  83
  84
  85
  86 New extensions
  87 --------------
  88
  89 GL_ARB_transpose_matrix
  90         Adds glLoadTransposeMatrixARB() and glMultTransposeMatrixARB()
  91         functions.
  92
  93 GL_ARB_texture_cube_map
  94         For cube-based reflection mapping.
  95
  96 GL_EXT_texture_add_env
  97         Adds GL_ADD texture environment mode.
  98         See http://www.berkelium.com/OpenGL/EXT/texture_env_add.txt
  99
 100 GL_EXT_texture_lod_bias
 101         Allows mipmapped texture blurring and sharpening.
 102
 103 GLX_EXT_visual_rating extension
 104         This extension has no effect in stand-alone Mesa (used for DRI).
 105
 106 GL_HP_occlusion_test
 107         Used for bounding box occlusion testing (see demos/occlude.c).
 108
 109 GL_SGIX_pixel_texture / GL_SGIS_pixel_texture
 110         Lets glDraw/CopyPixels draw a texture coordinate image.
 111
 112 GL_SGI_color_matrix
 113         Adds a color matrix and another set of scale and bias parameters
 114         to the glDraw/CopyPixels paths.
 115
 116 GL_SGI_color_table
 117         Adds additional color tables to the glDraw/Read/CopyPixels paths.
 118
 119 GL_EXT_histogram
 120         Compute histograms for glDraw/Read/CopyPixels.
 121
 122 GL_EXT_blend_func_separate
 123         This is the same as GL_INGR_blend_func_separate.
 124
 125 GL_ARB_texture_cube_mapping
 126         6-face cube mapping, nicer than sphere mapping
 127
 128 GL_EXT_texture_env_combine
 129         For advanced texture environment effects.
 130
 131
 132 Documentation for all these functions can be found at
 133 http://oss.sgi.com/projects/ogl-sample/registry/
 134
 135
 136
 137 GLX_SGI_make_current_read functionality
 138 ---------------------------------------
 139
 140 The functionality of this extension is needed for GLX 1.3 (and required
 141 for the Linux/OpenGL standards base).
 142
 143 Implementing this function required a **DEVICE DRIVER CHANGE**.
 144 The old SetBuffer() function has been replaced by SetReadBuffer() and
 145 SetDrawBuffer().  All device drivers will have to be updated because
 146 of this change.
 147
 148 The new function, glXMakeContextCurrent(), in GLX 1.3 now works in Mesa.
 149 The xdemos/wincopy.c program demonstrates it.
 150
 151
 152
 153 Image-related code changes
 154 --------------------------
 155
 156 The imaging path code used by glDrawPixels, glTexImage[123]D,
 157 glTexSubImage[123], etc has been rewritten.  It's now faster,
 158 uses less memory and has several bug fixes.  This work was
 159 actually started in Mesa 3.1 with the glTexImage paths but has now
 160 been carried over to glDrawPixels as well.
 161
 162
 163
 164 Device driver interface changes
 165 -------------------------------
 166
 167 Added new functions for hardware stencil buffer support:
 168    WriteStencilSpan
 169    ReadStencilSpan
 170    WriteStencilPixels
 171    ReadStencilPixels
 172
 173
 174 Removed old depth buffer functions:
 175    AllocDepthBuffer
 176    DepthTestSpan
 177    DepthTestPixels
 178    ReadDepthSpanFloat
 179    ReadDepthSpanInt
 180
 181
 182 Added new depth buffer functions:
 183    WriteDepthSpan
 184    ReadDepthSpan
 185    WriteDepthPixels
 186    ReadDepthPixels
 187
 188    These functions always read/write 32-bit GLuints.  This will allow
 189    drivers to have anywhere from 0 to 32-bit Z buffers without
 190    recompiling for 16 vs 32 bits as was previously needed.
 191
 192
 193 New texture image functions
 194    The entire interface for texture image specification has been updated.
 195    With the new functions, it's optional for Mesa to keep an internal copy
 196    of all textures.  Texture download should be a lot faster when the extra
 197    copy isn't made.
 198
 199 Misc changes
 200    TexEnv now takes a target argument
 201    Removed UseGlobalTexturePalette (use Enable function instead)
 202
 203
 204 Also added
 205    ReadPixels
 206    CopyPixels
 207
 208
 209 The SetBufffer function has been replaced by SetDrawBuffer and
 210 SetReadBuffer functions.  This lets core Mesa independently
 211 specify which buffer is to be used for reading and which for
 212 drawing.
 213
 214 The Clear function's mask parameter has changed.  Instead of
 215 mask being the flags specified by the user to glClear, the
 216 mask is now a bitmask of the DD_*_BIT flags in dd.h.  Now
 217 multiple color buffers can be specified for clearing (ala
 218 glDrawBuffers).  The driver's Clear function must also
 219 check the glColorMask glIndexMask, and glStencilMask settings
 220 and do the right thing.  See the X/Mesa, OS/Mesa, or FX/Mesa
 221 drivers for examples.
 222
 223
 224 The depth buffer changes shouldn't be hard to make for existing
 225 drivers.  In fact, it should simply the code.  Be careful with
 226 the depthBits value passed to gl_create_context().  1 is a bad
 227 value!  It should normally be 0, 16, 24, or 32.
 228
 229
 230 gl_create_framebuffer() takes new arguments which explicitly tell
 231 core Mesa which ancillary buffers (depth, stencil, accum, alpha)
 232 should be implemented in software.  Mesa hardware drivers should
 233 carefully set these flags depending on which buffers are in the
 234 graphics card.
 235
 236
 237
 238 Internal constants
 239 ------------------
 240
 241 Point and line size range and granularity limits are now stored
 242 in the gl_constants struct, which is the Const member of GLcontext.
 243 The limits are initialized from values in config.h but may be
 244 overridden by device drivers to reflect the limits of that driver's
 245 hardware.
 246
 247 Also added constants for NumAuxBuffers and SubPixelBits.
 248
 249
 250
 251 OpenGL Conformance
 252 ------------------
 253
 254 Mesa now passes all the OpenGL 1.1 conformance tests, except for
 255 antialiased lines.  AA lines fail on some, but not all, the tests.
 256 In order to fix the remaining failures, a new AA line algorithm will
 257 be needed (which computes coverage values for end-point fragments).
 258 This will be done for Mesa 3.5/3.6.
 259
 260
 261
 262 OpenGL 1.2 GL_ARB_imaging subset
 263 --------------------------------
 264
 265 Mesa 3.3 implements all the features of GL_ARB_imaging except for
 266 image convolution.  This will (hopefully) be done for Mesa 3.5/3.6.
 267
 268
 269
 270 ----------------------------------------------------------------------