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 XXX Things To Do Yet XXXX
 105 -------------------------
 106
 107 Verify x86 code for normal transformation works with new 4-element normal
 108 vector arrays.  Pretty sure the SSE code is wrong.
 109
 110 Allow multiple points to be rendered into one sw_span.
 111
 112 improve point/line rendering speed.
 113
 114 glVertexAttrib*NV(index>15) should cause an error.
 115
 116 isosurf with vertex program exhibits some missing triangles (probably
 117 when recycling the vertex buffer for long prims).
 118
 119
 120
 121 Porting Info
 122 ------------
 123
 124 If you're porting a DRI or other driver from Mesa 4.0.x to Mesa 4.1 here
 125 are some things to change:
 126
 127 1. ctx->Texture._ReallyEnabled is obsolete.
 128
 129    Since there are now 5 texture targets (1D, 2D, 3D, cube and rect) that
 130    left room for only 6 units (6*5 < 32) in this field.
 131    This field is being replaced by ctx->Texture._EnabledUnits which has one
 132    bit per texture unit.  If the bit k of _EnabledUnits is set, that means
 133    ctx->Texture.Unit[k]._ReallyEnabled is non-zero.  You'll have to look at
 134    ctx->Texture.Unit[k]._ReallyEnabled to learn if the 1D, 2D, 3D, cube or
 135    rect texture is enabled for unit k.
 136
 137    This also means that the constants TEXTURE1_*, TEXTURE2_*, etc are
 138    obsolete.
 139
 140    The tokens TEXTURE0_* have been replaced as well (since there's no
 141    significance to the "0" part:
 142
 143    old token           new token
 144    TEXTURE0_1D         TEXTURE_1D_BIT
 145    TEXTURE0_2D         TEXTURE_2D_BIT
 146    TEXTURE0_3D         TEXTURE_3D_BIT
 147    TEXTURE0_CUBE       TEXTURE_CUBE_BIT
 148    <none>              TEXTURE_RECT_BIT
 149
 150    These tokens are only used for the ctx->Texture.Unit[i].Enabled and
 151    ctx->Texture.Unit[i]._ReallyEnabled fields.  Exactly 0 or 1 bits will
 152    be set in _ReallyEnabled at any time!
 153
 154    Q: "What's the purpose of Unit[i].Enabled vs Unit[i]._ReallyEnabled?"
 155    A: The user can enable GL_TEXTURE_1D, GL_TEXTURE_2D, etc for any
 156       texure unit all at once (an unusual thing to do).
 157       OpenGL defines priorities that basically say GL_TEXTURE_2D has
 158       higher priority than GL_TEXTURE_1D, etc.  Also, just because a
 159       texture target is enabled by the user doesn't mean we'll actually
 160       use that texture!  If a texture object is incomplete (missing mip-
 161       map levels, etc) it's as if texturing is disabled for that target.
 162       The _ReallyEnabled field will have a bit set ONLY if the texture
 163       target is enabled and complete.  This spares the driver writer from
 164       examining a _lot_ of GL state to determine which texture target is
 165       to be used.
 166
 167
 168 2. Tnl tokens changes
 169
 170    During the implementation of GL_NV_vertex_program some of the vertex
 171    buffer code was changed.  Specifically, the VERT_* bits defined in
 172    tnl/t_context.h have been renamed to better match the conventions of
 173    GL_NV_vertex_program.  The old names are still present but obsolete.
 174    Drivers should use the newer names.
 175
 176    For example:  VERT_RGBA is now VERT_BIT_COLOR0 and
 177    VERT_SPEC_RGB is now VERT_BIT_COLOR1.
 178
 179
 180
 181 3. Read/Draw Buffer changes
 182
 183    The business of setting the current read/draw buffers in Mesa 4.0.x
 184    was complicated.  It's much simpler now in Mesa 4.1.
 185
 186    Here are the changes:
 187
 188    - Rename ctx->Color.DrawDestMask to ctx->Color._DrawDestMask
 189    - Rename ctx->Color.DriverDrawBuffer to ctx->Color._DriverDrawBuffer
 190    - Rename ctx->Pixel.DriverReadBuffer to ctx->Pixel._DriverReadBuffer
 191    - Removed ctx->Color.MultiDrawBuffer
 192    - Removed ctx->Driver.SetDrawBuffer
 193    - Added ctx->Driver.DrawBuffer and ctx->Driver.ReadBuffer.  These functions
 194      exactly correspond to glDrawBuffer and glReadBuffer calls.
 195      Many drivers will set ctx->Driver.DrawBuffer = _swrast_DrawBuffer and
 196      leave ctx->Draw.ReadBuffer NULL.
 197      DRI drivers should implement their own function for ctx->Driver.DrawBuffer
 198      and use it to set the current hardware drawing buffer.  You'll probably
 199      also want to check for GL_FRONT_AND_BACK mode and fall back to software.
 200      Call _swrast_DrawBuffer() too, to update the swrast state.
 201    - Removed swrast->Driver.SetReadBuffer
 202    - Added swrast->Driver.SetBuffer.  This function should be implemented by
 203      _all_ device drivers.  Mesa will call it to specify the buffer to use
 204      for span reading AND writing and point/line/triangle rendering.  There
 205      should be no confusion between current read or draw buffer anymore.
 206
 207
 208 4. _mesa_create_context() changes.  This function now takes a pointer to
 209    a __GLimports object.  The __GLimports structure contains function
 210    pointers to system functions like fprintf(), malloc(), etc.
 211    The _mesa_init_default_imports() function can be used to initialize
 212    a __GLimports object.  Most device drivers (like the DRI drivers)
 213    should use this.
 214
 215
 216
 217 ----------------------------------------------------------------------
 218 $Id: RELNOTES-4.1,v 1.14 2002/08/01 15:16:46 brianp Exp $