GL_MESA_packed_depth_stencil extension spec

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+XXX - Not complete yet!!!
+
+Name
+
+    MESA_packed_depth_stencil
+
+Name Strings
+
+    GL_MESA_packed_depth_stencil
+
+Contact
+
+    Keith Whitwell, VA Linux Systems Inc. (keithw 'at' valinux.com)
+    Brian Paul, VA Linux Systems Inc. (brianp 'at' valinux.com)
+
+Status
+
+    Not yet shipping.
+
+Version
+
+    $Id: MESA_packed_depth_stencil.spec,v 1.1 2000/11/03 14:58:45 brianp Exp $
+
+Number
+
+    ???
+
+Dependencies
+
+    EXT_abgr affects the definition of this extension
+    SGIS_texture4D affects the definition of this extension
+    EXT_cmyka affects the definition of this extension
+    ARB_packed_pixels affects the definition of this extension
+
+Overview
+	
+    Provides a mechanism for DrawPixels and ReadPixels to efficiently
+    transfer depth and stencil image data.  Specifically, we defined new
+    packed pixel formats and types which pack both stencil and depth
+    into one value.
+
+Issues:
+
+    1. Is this the right way to distinguish between 24/8 and 8/24
+       pixel formats?  Should we instead provide both:
+	
+       GL_DEPTH_STENCIL_MESA
+       GL_STENCIL_DEPTH_MESA
+
+       And perhaps just use GL_UNSIGNED_INT, GL_UNSIGNED_SHORT ?
+
+    2. If not, is it correct to use _REV to indicate that stencil
+       preceeds depth in the 1_15 and 8_24 formats?
+
+    3. Do we really want the GL_UNSIGNED_SHORT formats?  
+
+	
+New Procedures and Functions
+
+    None.
+
+New Tokens
+    
+    Accepted by the <format> parameter of ReadPixels and DrawPixels:
+
+	GL_DEPTH_STENCIL_MESA		0x8750
+
+    Accepted by the <type> parameter of ReadPixels and DrawPixels:
+
+	GL_UNSIGNED_INT_24_8_MESA	0x8751
+	GL_UNSIGNED_INT_8_24_REV_MESA	0x8752
+	GL_UNSIGNED_SHORT_15_1_MESA	0x8753
+	GL_UNSIGNED_SHORT_1_15_REV_MESA	0x8754
+
+Additions to Chapter 2 of the 1.1 Specification (OpenGL Operation)
+
+    None
+
+Additions to Chapter 3 of the 1.1 Specification (Rasterization)
+
+    One entry is added to table 3.5 (DrawPixels and ReadPixels formats).
+    The new table is:
+
+			Target
+	Format Name	Buffer	Element Meaning and Order
+	-----------	------	-------------------------
+	COLOR_INDEX	Color	Color index
+	STENCIL_INDEX	Stencil Stencil index
+	DEPTH_COMPONENT Depth	Depth component
+	RED		Color	R component
+	GREEN		Color	G component
+	BLUE		Color	B component
+	ALPHA		Color	A component
+	RGB		Color	R, G, B components
+	RGBA		Color	R, G, B, A components
+	BGRA	        Color   B, G, R, A components
+	ABGR_EXT	Color	A, B, G, R components
+	CMYK_EXT	Color	Cyan, Magenta, Yellow, Black components
+	CMYKA_EXT	Color	Cyan, Magenta, Yellow, Black, A components
+	LUMINANCE	Color	Luminance component
+	LUMINANCE_ALPHA Color	Luminance, A components
+	DEPTH_STENCIL   Depth,  Depth component, stencil index.
+			Stencil
+
+	Table 3.5: DrawPixels and ReadPixels formats.  The third column
+	gives a description of and the number and order of elements in a
+	group.
+
+    Add to the description of packed pixel formats:
+
+	<type> Parameter		Data	of	  Matching
+	Token Name			Type	Elements  Pixel Formats
+	----------------		----	--------  -------------
+
+	UNSIGNED_BYTE_3_3_2	      ubyte   3	      RGB
+	UNSIGNED_BYTE_2_3_3_REV       ubyte   3	      RGB
+	UNSIGNED_SHORT_5_6_5	      ushort  3	      RGB
+	UNSIGNED_SHORT_5_6_5_REV      ushort  3	      RGB
+	UNSIGNED_SHORT_4_4_4_4	      ushort  4	      RGBA,BGRA,ABGR_EXT,CMYK_EXT
+	UNSIGNED_SHORT_4_4_4_4_REV    ushort  4	      RGBA,BGRA
+	UNSIGNED_SHORT_5_5_5_1	      ushort  4	      RGBA,BGRA,ABGR_EXT,CMYK_EXT
+	UNSIGNED_SHORT_1_5_5_5_REV    ushort  4	      RGBA,BGRA
+	UNSIGNED_INT_8_8_8_8	      uint    4	      RGBA,BGRA,ABGR_EXT,CMYK_EXT
+	UNSIGNED_INT_8_8_8_8_REV      uint    4	      RGBA,BGRA
+	UNSIGNED_INT_10_10_10_2       uint    4	      RGBA,BGRA,ABGR_EXT,CMYK_EXT
+	UNSIGNED_INT_2_10_10_10_REV   uint    4	      RGBA,BGRA
+	UNSIGNED_SHORT_15_1_MESA      ushort  2       DEPTH_STENCIL_MESA
+	UNSIGNED_SHORT_1_15_REV_MESA  ushort  2       DEPTH_STENCIL_MESA
+	UNSIGNED_SHORT_24_8_MESA      ushort  2       DEPTH_STENCIL_MESA
+	UNSIGNED_SHORT_8_24_REV_MESA  ushort  2       DEPTH_STENCIL_MESA
+
+	UNSIGNED_INT_8_24:
+
+	     31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10	9  8  7  6  5  4  3  2	1  0
+	    +-----------------------+-----------------------------------------------------------------------+
+	    |			    |			     			    			    |
+	    +-----------------------+-----------------------------------------------------------------------+
+
+		    first					second		    
+		    element					element		    
+
+
+	UNSIGNED_INT_24_8:
+
+	     31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10	9  8  7  6  5  4  3  2	1  0
+	    +----------------------------------------------------------------------+------------------------+
+	    |			    			     			   | 			    |
+	    +----------------------------------------------------------------------+------------------------+
+
+		    first								  second		    
+		    element								  element		    
+
+	UNSIGNED_SHORT_15_1:
+
+	      15  14  13  12  11  10  9   8   7   6   5   4   3   2   1   0
+	    +-----------------------------------------------------------+---+
+	    |					    			|   |
+	    +-----------------------------------------------------------+---+
+
+	    		first						second	
+			element						element	
+
+
+	UNSIGNED_SHORT_1_15_REV:
+
+	      15  14  13  12  11  10  9   8   7   6   5   4   3   2   1   0
+	    +---+-----------------------------------------------------------+
+	    |	|		     					    |
+	    +---+-----------------------------------------------------------+
+
+	    second		    first
+	    element		    element
+
+    The assignment of elements to fields in the packed pixel is as
+    described in the table below:
+
+			   First       Second	Third	    Fourth
+	Format		   Element     Element	Element     Element
+	------		   -------     -------	-------     -------
+	RGB		   red	       green	blue
+	RGBA		   red	       green	blue	    alpha
+	BGRA		   blue	       green	red	    alpha
+	ABGR_EXT	   alpha       blue	green	    red
+	CMYK_EXT	   cyan	       magenta	yellow	    black
+	DEPTH_STENCIL_MESA depth       stencil
+
+Additions to Chapter 4 of the 1.1 Specification (Per-Fragment Operations
+and the Frame Buffer)
+
+    The new format is added to the discussion of Obtaining Pixels from the
+    Framebuffer.  It should read " If the <format> is one of RED, GREEN,
+    BLUE, ALPHA, RGB, RGBA, ABGR_EXT, LUMINANCE, or LUMINANCE_ALPHA, and
+    the GL is in color index mode, then the color index is obtained."
+
+    The new format is added to the discussion of Index Lookup.  It should
+    read "If <format> is one of RED, GREEN, BLUE, ALPHA, RGB, RGBA,
+    ABGR_EXT, LUMINANCE, or LUMINANCE_ALPHA, then the index is used to
+    reference 4 tables of color components: PIXEL_MAP_I_TO_R,
+    PIXEL_MAP_I_TO_G, PIXEL_MAP_I_TO_B, and PIXEL_MAP_I_TO_A."
+
+
+Additions to Chapter 5 of the 1.1 Specification (Special Functions)
+
+    None
+
+Additions to Chapter 6 of the 1.1 Specification (State and State Requests)
+
+    None
+
+Additions to the GLX Specification
+
+    None
+
+GLX Protocol
+
+    TBD
+
+Errors
+
+    None
+
+New State
+
+    None
+
+Revision History
+
+    Version 1.0 - 23 Sep 2000
+        Keith's original version.
+
+    Version 1.1 - 3 Nov 2000
+        Brian's edits, assigned values to new enums.
+