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.
18 New Features in Mesa 4.1
19 ------------------------
21 New extensions. Docs at http://oss.sgi.com/projects/ogl-sample/registry/
25 NVIDIA's vertex programming extension
27 GL_NV_vertex_program1_1
29 A few features built on top of GL_NV_vertex_program
33 This is the ARB-approved version of GL_MESA_window_pos
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
43 Shadow mapping with depth textures.
44 This is the ARB-approved version of GL_SGIX_shadow.
48 Allows one to specify the luminance of shadowed pixels.
49 This is the ARB-approved version of GL_SGIX_shadow_ambient.
53 Extends the set of GL_ARB_shadow texture comparision functions to
54 include all eight of standard OpenGL dept-test functions.
56 GL_ARB_point_parameters
58 This is basically the same as GL_EXT_point_parameters.
60 GL_ARB_texture_env_crossbar
62 Allows any texture combine stage to reference any texture source unit.
66 For rendering points as textured quads. Useful for particle effects.
68 GL_NV_texture_rectangle (new in 4.0.4 actually)
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.
73 GL_EXT_multi_draw_arrays
75 Allows arrays of vertex arrays to be rendered with one call.
77 GL_EXT_stencil_two_side
79 Separate stencil modes for front and back-facing polygons.
81 GLX_SGIX_fbconfig & GLX_SGIX_pbuffer
83 Off-screen rendering support.
90 A number of Mesa's software drivers haven't been actively maintained for
91 some time. We rely on volunteers to maintain many of these drivers.
92 Here's the current status of all included drivers:
96 ---------------------- ---------------------
97 XMesa (Xlib) implements OpenGL 1.3
98 OSMesa (off-screen) implements OpenGL 1.3
99 FX (3dfx Voodoo1/2) implements OpenGL 1.3
100 SVGA implements OpenGL 1.3
101 Wind River UGL implements OpenGL 1.3
102 Windows/Win32 implements OpenGL 1.3
103 DOS/DJGPP implements OpenGL 1.3
104 GGI implements OpenGL 1.3
105 BeOS needs updating (underway)
106 Allegro needs updating
115 1. Frames per second printing
117 GLUT now looks for an environment variable called "GLUT_FPS". If it's
118 set, GLUT will print out a frames/second statistic to stderr when
119 glutSwapBuffers() is called. By default, frames/second is computed
120 and displayed once every 5 seconds. You can specify a different
121 interval (in milliseconds) when you set the env var. For example
122 'export GLUT_FPS=1000' or 'setenv GLUT_FPS 1000' will set the interval
125 NOTE: the demo or application must call the glutInit() function for
126 this to work. Otherwise, the env var will be ignored.
128 Finally, this feature may not be reliable in multi-window programs.
131 2. glutGetProcAddress() function
135 void *glutGetProcAddress(const char *procName)
137 is a wrapper for glXGetProcAddressARB() and wglGetProcAddress(). It
138 lets you dynamically get the address of an OpenGL function at runtime.
139 The GLUT_API_VERSION has been bumped to 5, but I haven't bumped the
140 GLUT version number from 3.7 since that's probably Mark Kilgard's role.
142 This function should probably also be able to return the address of
143 GLUT functions themselves, but it doesn't do that yet.
147 XXX Things To Do Yet XXXX
148 -------------------------
150 isosurf with vertex program exhibits some missing triangles (probably
151 when recycling the vertex buffer for long prims).
158 If you're porting a DRI or other driver from Mesa 4.0.x to Mesa 4.1 here
159 are some things to change:
161 1. ctx->Texture._ReallyEnabled is obsolete.
163 Since there are now 5 texture targets (1D, 2D, 3D, cube and rect) that
164 left room for only 6 units (6*5 < 32) in this field.
165 This field is being replaced by ctx->Texture._EnabledUnits which has one
166 bit per texture unit. If the bit k of _EnabledUnits is set, that means
167 ctx->Texture.Unit[k]._ReallyEnabled is non-zero. You'll have to look at
168 ctx->Texture.Unit[k]._ReallyEnabled to learn if the 1D, 2D, 3D, cube or
169 rect texture is enabled for unit k.
171 This also means that the constants TEXTURE1_*, TEXTURE2_*, etc are
174 The tokens TEXTURE0_* have been replaced as well (since there's no
175 significance to the "0" part:
178 TEXTURE0_1D TEXTURE_1D_BIT
179 TEXTURE0_2D TEXTURE_2D_BIT
180 TEXTURE0_3D TEXTURE_3D_BIT
181 TEXTURE0_CUBE TEXTURE_CUBE_BIT
182 <none> TEXTURE_RECT_BIT
184 These tokens are only used for the ctx->Texture.Unit[i].Enabled and
185 ctx->Texture.Unit[i]._ReallyEnabled fields. Exactly 0 or 1 bits will
186 be set in _ReallyEnabled at any time!
188 Q: "What's the purpose of Unit[i].Enabled vs Unit[i]._ReallyEnabled?"
189 A: The user can enable GL_TEXTURE_1D, GL_TEXTURE_2D, etc for any
190 texure unit all at once (an unusual thing to do).
191 OpenGL defines priorities that basically say GL_TEXTURE_2D has
192 higher priority than GL_TEXTURE_1D, etc. Also, just because a
193 texture target is enabled by the user doesn't mean we'll actually
194 use that texture! If a texture object is incomplete (missing mip-
195 map levels, etc) it's as if texturing is disabled for that target.
196 The _ReallyEnabled field will have a bit set ONLY if the texture
197 target is enabled and complete. This spares the driver writer from
198 examining a _lot_ of GL state to determine which texture target is
202 2. Tnl tokens changes
204 During the implementation of GL_NV_vertex_program some of the vertex
205 buffer code was changed. Specifically, the VERT_* bits defined in
206 tnl/t_context.h have been renamed to better match the conventions of
207 GL_NV_vertex_program. The old names are still present but obsolete.
208 Drivers should use the newer names.
210 For example: VERT_RGBA is now VERT_BIT_COLOR0 and
211 VERT_SPEC_RGB is now VERT_BIT_COLOR1.
215 3. Read/Draw Buffer changes
217 The business of setting the current read/draw buffers in Mesa 4.0.x
218 was complicated. It's much simpler now in Mesa 4.1.
220 Here are the changes:
222 - Renamed ctx->Color.DrawDestMask to ctx->Color._DrawDestMask
223 - Removed ctx->Color.DriverDrawBuffer
224 - Removed ctx->Pixel.DriverReadBuffer
225 - Removed ctx->Color.MultiDrawBuffer
226 - Removed ctx->Driver.SetDrawBuffer()
227 - Removed swrast->Driver.SetReadBuffer().
228 - Added ctx->Color._DrawDestMask - a bitmask of FRONT/BACK_LEFT/RIGHT_BIT
229 values to indicate the current draw buffers.
230 - Added ctx->Pixel._ReadSrcMask to indicate the source for pixel reading.
231 The value is _one_ of the FRONT/BACK_LEFT/RIGHT_BIT values.
232 - Added ctx->Driver.DrawBuffer() and ctx->Driver.ReadBuffer().
233 These functions exactly correspond to glDrawBuffer and glReadBuffer calls.
234 Many drivers will set ctx->Driver.DrawBuffer = _swrast_DrawBuffer and
235 leave ctx->Draw.ReadBuffer NULL.
236 DRI drivers should implement their own function for ctx->Driver.DrawBuffer
237 and use it to set the current hardware drawing buffer. You'll probably
238 also want to check for GL_FRONT_AND_BACK mode and fall back to software.
239 Call _swrast_DrawBuffer() too, to update the swrast state.
240 - Added swrast->Driver.SetBuffer().
241 This function should be implemented by all device drivers that use swrast.
242 Mesa will call it to specify the buffer to use for span reading AND
243 writing and point/line/triangle rendering.
244 There should be no confusion between current read or draw buffer anymore.
245 - Added swrast->CurrentBuffer to indicate which color buffer to read/draw.
246 Will be FRONT_LEFT_BIT, BACK_LEFT_BIT, FRONT_RIGHT_BIT or BACK_RIGHT_BIT.
247 This value is usually passed to swrast->Driver.SetBuffer().
250 4. _mesa_create_context() changes. This function now takes a pointer to
251 a __GLimports object. The __GLimports structure contains function
252 pointers to system functions like fprintf(), malloc(), etc.
253 The _mesa_init_default_imports() function can be used to initialize
254 a __GLimports object. Most device drivers (like the DRI drivers)
258 5. In tnl's struct vertex_buffer, the field "ProjectedClipCoords"
259 has been replaced by "NdcPtr" to better match the OpenGL spec's
263 6. Since GL_EXT_stencil_two_side has been implemented, many of the
264 ctx->Stencil fields are now 2-element arrays. For example,
265 "GLenum Ref" is now "GLenum Ref[2]" The [0] elements are the front-face
266 values and the [1] elements are the back-face values.
267 ctx->Stencil.ActiveFace is 0 or 1 to indicate the current face for
268 the glStencilOp/Func/Mask() functions.
269 ctx->Stencil.TestTwoSide controls whether or not 1 or 2-sided stenciling
273 7. Removed ctx->Polygon._OffsetAny. Removed ctx->Polygon.OffsetMRD.
276 8. GLfloat / GLchan changes:
278 - Changed ctx->Driver.ClearColor() to take GLfloat[4] instead of GLchan[4].
279 ctx->Color.ClearColor is now GLfloat[4] too.
280 - Changed ctx->Driver.AlphaRef() to take GLfloat instead of GLchan.
281 - ctx->Color.AlphaRef is now GLfloat.
282 - texObj->BorderColor is now GLfloat[4]. texObj->_BorderChan is GLchan[4].
284 This is part of an effort to remove all GLchan types from core Mesa so
285 that someday we can support 8, 16 and 32-bit color channels dynamically
286 at runtime, instead of at compile-time.
289 9. GLboolean ctx->Tranform.ClipEnabled[MAX_CLIP_PLANES] has been replaced
290 by GLuint ctx->Transform.ClipPlanesEnabled. The later is a bitfield.
293 10. There's a new matrix_stack type in mtypes.h used for the Modelview,
294 Projection, Color and Texcoord matrix stacks.
297 11. The ctx->Current.* fields have changed a lot. Now, there's a
298 ctx->Current.Attrib[] array for all vertex attributes which matches
299 the NV vertex program conventions.
302 ----------------------------------------------------------------------
303 $Id: RELNOTES-4.1,v 1.20 2002/10/11 17:42:48 brianp Exp $