docs/RELNOTES-4.1

   1
   2                             Mesa 4.1 release notes
   3
   4                             <month>, <day>, 2002
   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 Even numbered versions (such as 4.0) designate stable releases.
  15 Odd numbered versions (such as 4.1) designate new developmental releases.
  16
  17
  18 New Features in Mesa 4.1
  19 ------------------------
  20
  21 New extensions.  Docs at http://oss.sgi.com/projects/ogl-sample/registry/
  22
  23 GL_NV_vertex_program
  24
  25     NVIDIA's vertex programming extension
  26
  27 GL_NV_vertex_program1_1
  28
  29     A few features built on top of GL_NV_vertex_program
  30
  31 GL_ARB_window_pos
  32
  33     This is the ARB-approved version of GL_MESA_window_pos
  34
  35 GL_ARB_depth_texture
  36
  37     This is the ARB-approved version of GL_SGIX_depth_texture.
  38     It allows depth (Z buffer) data to be stored in textures.
  39     This is used by GL_ARB_shadow
  40
  41 GL_ARB_shadow
  42
  43     Shadow mapping with depth textures.
  44     This is the ARB-approved version of GL_SGIX_shadow.
  45
  46 GL_ARB_shadow_ambient
  47
  48     Allows one to specify the luminance of shadowed pixels.
  49     This is the ARB-approved version of GL_SGIX_shadow_ambient.
  50
  51 GL_EXT_shadow_funcs
  52
  53     Extends the set of GL_ARB_shadow texture comparision functions to
  54     include all eight of standard OpenGL dept-test functions.
  55
  56 GL_ARB_point_parameters
  57
  58     This is basically the same as GL_EXT_point_parameters.
  59
  60 GL_ARB_texture_env_crossbar
  61
  62     Allows any texture combine stage to reference any texture source unit.
  63
  64 GL_NV_point_sprite
  65
  66     For rendering points as textured quads.  Useful for particle effects.
  67
  68 GL_NV_texture_rectangle
  69
  70     Allows one to use textures with sizes that are not powers of two.
  71     Note that mipmapping and several texture wrap modes are not allowed.
  72
  73 GL_EXT_multi_draw_arrays
  74
  75     Allows arrays of vertex arrays to be rendered with one call.
  76
  77
  78
  79 Device Driver Status
  80 --------------------
  81
  82 A number of Mesa's software drivers haven't been actively maintained for
  83 some time.  We rely on volunteers to maintain many of these drivers.
  84 Here's the current status of all included drivers:
  85
  86
  87 Driver                  Status
  88 ----------------------  ---------------------
  89 XMesa (Xlib)            implements OpenGL 1.3
  90 OSMesa (off-screen)     implements OpenGL 1.3
  91 FX (3dfx Voodoo1/2)     implements OpenGL 1.3
  92 SVGA                    implements OpenGL 1.3
  93 Wind River UGL          implements OpenGL 1.3
  94 Windows/Win32           implements OpenGL 1.3
  95 DOS/DJGPP               implements OpenGL 1.3
  96 GGI                     implements OpenGL 1.3
  97 BeOS                    needs updating (underway)
  98 Allegro                 needs updating
  99 D3D                     needs updating
 100 DOS                     needs updating
 101
 102
 103
 104 Porting Information
 105 -------------------
 106
 107 When moving from Mesa 4.0.x to Mesa 4.1 there are a number of things
 108 you may have to update.
 109
 110 1. _mesa_create_context() changes.  This function now takes a pointer to
 111    a __GLimports object.  The __GLimports structure contains function
 112    pointers to system functions like fprintf(), malloc(), etc.
 113    The _mesa_init_default_imports() function can be used to initialize
 114    a __GLimports object.  Most device drivers (like the DRI drivers)
 115    should use this.
 116
 117 2. more to come...
 118
 119
 120
 121 XXX Things To Do Yet XXXX
 122 -------------------------
 123
 124 Verify x86 code for normal transformation works with new 4-element normal
 125 vector arrays.  Pretty sure the SSE code is wrong.
 126
 127 Finish up NV_vertex_program support for evaluators.  Vertex arrays seem
 128 to work as of 4/21/2002.
 129
 130 Allow multiple points to be rendered into one sw_span.
 131
 132 improve point/line rendering speed.
 133
 134 _tnl_end() has flushing forced on.
 135
 136 readpixels from stencil/z should respect ctx->ReadBuffer
 137
 138 glVertexAttrib*NV(index>15) should cause an error.
 139
 140 isosurf with vertex program exhibits some missing triangles (probably
 141 when recycling the vertex buffer for long prims).
 142
 143
 144
 145 Porting Info
 146 ------------
 147
 148 If you're porting a DRI or other driver from Mesa 4.0.x to Mesa 4.1 here
 149 are some things to change:
 150
 151 1. ctx->Texture._ReallyEnabled is obsolete.
 152
 153    Since there are now 5 texture targets (1D, 2D, 3D, cube and rect) that
 154    left room for only 6 units (6*5 < 32) in this field.
 155    This field is being replaced by ctx->Texture._EnabledUnits which has one
 156    bit per texture unit.  If the bit k of _EnabledUnits is set, that means
 157    ctx->Texture.Unit[k]._ReallyEnabled is non-zero.  You'll have to look at
 158    ctx->Texture.Unit[k]._ReallyEnabled to learn if the 1D, 2D, 3D, cube or
 159    rect texture is enabled for unit k.
 160
 161    This also means that the constants TEXTURE1_*, TEXTURE2_*, etc are
 162    obsolete.
 163
 164    The tokens TEXTURE0_* have been replaced as well (since there's no
 165    significance to the "0" part:
 166
 167    old token           new token
 168    TEXTURE0_1D         TEXTURE_1D_BIT
 169    TEXTURE0_2D         TEXTURE_2D_BIT
 170    TEXTURE0_3D         TEXTURE_3D_BIT
 171    TEXTURE0_CUBE       TEXTURE_CUBE_BIT
 172    <none>              TEXTURE_RECT_BIT
 173
 174    These tokens are only used for the ctx->Texture.Unit[i].Enabled and
 175    ctx->Texture.Unit[i]._ReallyEnabled fields.  Exactly 0 or 1 bits will
 176    be set in _ReallyEnabled at any time!
 177
 178    Q: "What's the purpose of Unit[i].Enabled vs Unit[i]._ReallyEnabled?"
 179    A: The user can enable GL_TEXTURE_1D, GL_TEXTURE_2D, etc for any
 180       texure unit all at once (an unusual thing to do).
 181       OpenGL defines priorities that basically say GL_TEXTURE_2D has
 182       higher priority than GL_TEXTURE_1D, etc.  Also, just because a
 183       texture target is enabled by the user doesn't mean we'll actually
 184       use that texture!  If a texture object is incomplete (missing mip-
 185       map levels, etc) it's as if texturing is disabled for that target.
 186       The _ReallyEnabled field will have a bit set ONLY if the texture
 187       target is enabled and complete.  This spares the driver writer from
 188       examining a _lot_ of GL state to determine which texture target is
 189       to be used.
 190
 191
 192 2. Tnl tokens changes
 193
 194    During the implementation of GL_NV_vertex_program some of the vertex
 195    buffer code was changed.  Specifically, the VERT_* bits defined in
 196    tnl/t_context.h have been renamed to better match the conventions of
 197    GL_NV_vertex_program.  The old names are still present but obsolete.
 198    Drivers should use the newer names.
 199
 200    For example:  VERT_RGBA is now VERT_BIT_COLOR0 and
 201    VERT_SPEC_RGB is now VERT_BIT_COLOR1.
 202
 203
 204
 205 3. Read/Draw Buffer changes
 206
 207    The business of setting the current read/draw buffers in Mesa 4.0.x
 208    was complicated.  It's much simpler now in Mesa 4.1.
 209
 210    Here are the changes:
 211
 212    - Rename ctx->Color.DrawDestMask to ctx->Color._DrawDestMask
 213    - Rename ctx->Color.DriverDrawBuffer to ctx->Color._DriverDrawBuffer
 214    - Rename ctx->Pixel.DriverReadBuffer to ctx->Pixel._DriverReadBuffer
 215    - Removed ctx->Color.MultiDrawBuffer
 216    - Removed ctx->Driver.SetDrawBuffer
 217    - Added ctx->Driver.DrawBuffer and ctx->Driver.ReadBuffer.  These functions
 218      exactly correspond to glDrawBuffer and glReadBuffer calls.
 219      Many drivers will set ctx->Driver.DrawBuffer = _swrast_DrawBuffer and
 220      leave ctx->Draw.ReadBuffer NULL.
 221      DRI drivers should implement their own function for ctx->Driver.DrawBuffer
 222      and use it to set the current hardware drawing buffer.  You'll probably
 223      also want to check for GL_FRONT_AND_BACK mode and fall back to software.
 224      Call _swrast_DrawBuffer() too, to update the swrast state.
 225    - Removed swrast->Driver.SetReadBuffer
 226    - Added swrast->Driver.SetBuffer.  This function should be implemented by
 227      _all_ device drivers.  Mesa will call it to specify the buffer to use
 228      for span reading AND writing and point/line/triangle rendering.  There
 229      should be no confusion between current read or draw buffer anymore.
 230
 231
 232
 233
 234 ----------------------------------------------------------------------
 235 $Id: RELNOTES-4.1,v 1.13 2002/07/09 01:28:03 brianp Exp $