Mesa 3.5 release notes

                             Month ??, 2000

                             PLEASE READ!!!!



Introduction
------------

Mesa uses an even/odd version number scheme like the Linux kernel.
Odd numbered versions (such as 3.3) designate new developmental releases.
Even numbered versions (such as 3.4) designate stable releases.

The internal structure of Mesa 3.5 is (will be) changed so that it
is more modular.  The motivation is better support of 3D hardware
such as T&L hardware in which much of core Mesa isn't needed.

Details to come...



New Extensions
--------------

GL_EXT_convolution
	Adds image convolution to glRead/Copy/DrawPixels/TexImage.

GL_ARB_imaging
	This is the optional imaging subset of OpenGL 1.2.
	It's the GL_EXT_convolution, GL_HP_convolution_border_modes,
	GL_EXT_histogram, GL_EXT_color_table, GL_EXT_color_subtable
	GL_EXT_blend_color, GL_EXT_blend_minmax, GL_EXT_blend_subtract
	and GL_SGI_color_matrix extensions all rolled together.
	This is supported in all software renderers but not in all
	hardware drivers (3dfx for example).

GL_ARB_texture_compression
	This is supported in Mesa but only used by the 3dfx DRI drivers
	for Voodoo4 and later.

GL_ARB_texture_env_add
	This is identical to GL_EXT_texture_env_add.

GL_NV_blend_square
	Adds extra blend source and dest factors which allow squaring
	of color values.



libOSMesa.so
------------

libOSMesa.so is a new library which contains the OSMesa interface for
off-screen rendering.  Apps which need the OSMesa interface should link
with both -lOSMesa and -lGL.  This change was made so that stand-alone
Mesa works the same way as XFree86/DRI's libGL.



Device Driver Changes / Core Mesa Changes
-----------------------------------------

The ctx->Driver.LogicOp() function has been removed.  It used to
be called during state update in order to determine if the driver
could do glLogicOp() operations, and if not, set the SWLogicOpEnabled
flag.  Drivers should instead examine the LogicOp state themselves
and choose specialized point, line, and triangle functions appropriately,
or fall back to software rendering.  The Xlib driver was the only driver
to use this function.  And since the Xlib driver no longer draws
points, lines or triangles using Xlib, the LogicOp function isn't needed.

The ctx->Driver.Dither() function has been removed.  Drivers should
detect dither enable/disable via ctx->Driver.Enable() instead.

The ctx->Driver.IndexMask() and ctx->Driver.ColorMask() functions
are now just called from glIndexMask and glColorMask like the other
GL state-changing functions.  They are no longer called from inside
gl_update_state().  Also, they now return void.  The change was made
mostly for sake of uniformity.

The NEW_DRVSTATE[0123] flags have been removed.  They weren't being used
and are obsolete w.r.t. the way state updates are done in DRI drivers.


Removed obsolete gl_create_visual() and gl_destroy_visual().

Renamed functions (new namespace):

old				new
gl_create_framebuffer		_mesa_create_framebuffer
gl_destroy_framebuffer		_mesa_destroy_framebuffer
gl_create_context		_mesa_create_context
gl_destroy_context		_mesa_destroy_context
gl_context_initialize		_mesa_context_initialize
gl_copy_context			_mesa_copy_context
gl_make_current			_mesa_make_current
gl_make_current2		_mesa_make_current2
gl_get_current_context		_mesa_get_current_context
gl_flush_vb			_mesa_flush_vb
gl_warning			_mesa_warning
gl_compile_error		_mesa_compile_error


All the drivers have been updated, but not all of them have been
tested since I can't test some platforms (DOS, Windows, Allegro, etc).


Multitexture
------------

Three texture units are now supported by default.  We'll allow more
than three texture units when we fix some bitfield issues.  In at least
one place we have a 32-bit bitfield which is fully allocated, leaving
no space for texture unit #3 or higher.

The TEXTURE1_1D, TEXTURE1_2D, etc constants may go away in the future.
Currently, they're only used in the ctx->Texture.ReallyEnabled field.
This bitfield is just a conglomerate of ctx->Texture.Unit[i].ReallyEnabled
for all <i> texture units.  ctx->Texture.ReallyEnabled may become a
GLboolean.  Then, drivers will have to loop over the texture units to
examine ctx->Texture.Unit[i].ReallyEnabled.




OpenGL SI related changes
-------------------------

In an effort to make Mesa's internal interfaces more like the OpenGL
SI interfaces, a number of changes have been made:

1. Importing the SI's glcore.h file which defines a number of
interface structures like __GLimports and __GLexports.

2. Renamed "struct gl_context" to "struct __GLcontextRec".

3. Added __glCoreCreateContext() and __glCoreNopDispatch() functions.

4. The GLcontext member Visual is no longer a pointer.

5. New file: imports.c to setup default import functions for Mesa.


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$Id: RELNOTES-3.5,v 1.6 2000/10/23 19:46:11 brianp Exp $