Commit adc4d21d authored by Brian Paul's avatar Brian Paul
Browse files

finished the spec

parent efaa8be7
......@@ -13,7 +13,8 @@ Contact
Status
Shipping (Mesa 4.0.4 and later)
Shipping (Mesa 4.0.4 and later. Only implemented in particular
XFree86/DRI drivers.)
Version
......@@ -31,8 +32,11 @@ Dependencies
Overview
This extensions provides a way to convert pointers in an AGP memory region
into byte offsets into the AGP apeture.
This extensions provides a way to convert pointers in an AGP memory
region into byte offsets into the AGP aperture.
Note, this extension depends on GLX_NV_vertex_array_range, for which
no real specification exists. See GL_NV_vertex_array_range for more
information.
IP Status
......@@ -44,7 +48,7 @@ Issues
New Procedures and Functions
uint glXGetAGPOffsetMESA( const void *pointer )
GLuint glXGetAGPOffsetMESA( const GLvoid *pointer )
New Tokens
......@@ -54,10 +58,22 @@ Additions to the OpenGL 1.4 Specification
None
Additions to Chapter ??? the GLX 1.4 Specification (??? chapter name)
Additions to Chapter 3 the GLX 1.4 Specification (Functions and Errors)
XXX to do
Add a new section, 3.6 as follows:
3.6 AGP Memory Access
On "PC" computers, AGP memory can be allocated with glXAllocateMemoryNV
and freed with glXFreeMemoryNV. Sometimes it's useful to know where a
block of AGP memory is located with respect to the start of the AGP
aperature. The function
GLuint glXGetAGPOffsetMESA( const GLvoid *pointer )
Returns the offset of the given memory block from the start of AGP
memory in basic machine units (i.e. bytes). If pointer is invalid
the value ~0 will be returned.
GLX Protocol
......@@ -75,3 +91,4 @@ New State
Revision History
20 September 2002 - Initial draft
2 October 2002 - finished GLX chapter 3 additions
......@@ -27,10 +27,22 @@ Dependencies
OpenGL 1.0 or later is required
This extensions is written against the OpenGL 1.4 Specification.
NV_texture_rectangle effects the definition of this extension.
Overview
This extension supports texture images in the YCbCr format.
This extension supports texture images in the YCbCr format. There is
no support for converting YCbCr images to RGB or vice versa. The
intention is for YCbCr image data to be directly sent to the renderer
without any pixel transfer operations. Only 2D texture images are
supported (not glDrawPixels, glReadPixels, etc).
A YCbCr pixel (texel) is a 16-bit unsigned short with two components.
The first component is luminance (Y). For pixels in even-numbered
image columns, the second component is Cb. For pixels in odd-numbered
image columns, the second component is Cr. If one were to convert the
data to RGB one would need to examine two pixels from columns N and N+1
(where N is even) to deduce the RGB color.
IP Status
......@@ -62,7 +74,74 @@ Additions to Chapter 2 of the OpenGL 1.4 Specification (OpenGL Operation)
Additions to Chapter 3 of the OpenGL 1.4 Specification (Rasterization)
XXX update texture image section
In section 3.6.4, Rasterization of Pixel Rectangles, on page 102,
add the following to Table 3.8 (Packed pixel formats):
type Parameter GL Data Number of Matching
Token Name Type Components Pixel Formats
-------------- ------- ---------- -------------
UNSIGNED_SHORT_8_8_MESA ushort 3 YCBCR_422_MESA
UNSIGNED_SHORT_8_8_REV_MESA ushort 3 YCBCR_422_MESA
In section 3.6.4, Rasterization of Pixel Rectangles, on page 102,
add the following to Table 3.10 (UNSIGNED_SHORT formats):
UNSIGNED_SHORT_8_8_MESA:
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+-------------------------------+-------------------------------+
| 1st | 2nd |
+-------------------------------+-------------------------------+
UNSIGNED_SHORT_8_8_REV_MESA:
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+-------------------------------+-------------------------------+
| 2nd | 1st |
+-------------------------------+-------------------------------+
In section 3.6.4, Rasterization of Pixel Rectangles, on page 102,
add the following to Table 3.12 (Packed pixel fiedl assignments):
First Second Third Fourth
Format Element Element Element Element
------ ------- ------- ------- -------
YCBCR_422_MESA luminance chroma
In section 3.8.1, Texture Image Specification, on page 125, add
another item to the list of TexImage2D and TexImage3D equivalence
exceptions:
* The value of internalformat and format may be YCBCR_MESA to
indicate that the image data is in YCbCr format. type must
be either UNSIGNED_SHORT_8_8_MESA or UNSIGNED_SHORT_8_8_REV_MESA
as seen in tables 3.8 and 3.10. Table 3.12 describes the mapping
between Y and Cb/Cr to the components.
If NV_texture_rectangle is supported target may also be
TEXTURE_RECTANGLE_NV or PROXY_TEXTURE_RECTANGLE_NV.
All pixel transfer operations are bypassed. The texture is stored as
YCbCr, not RGB. Queries of the texture's red, green and blue component
sizes will return zero.
In section 3.8.1, Texture Image Specification, on page 126, add
another item to the list of TexImage1D and TexImage2D equivalence
exceptions:
* The value of internalformat and format can not be YCBCR_MESA.
In section 3.8.2, Alternate Texture Image Specification Commands, on
page 129, insert this paragraph after the first full paragraph on the
page:
"If the internal storage format of the image being updated by
TexSubImage2D is YCBCR_MESA then format must be YCBCR_MESA.
The error INVALID_OPERATION will be generated otherwise."
Additions to Chapter 4 of the OpenGL 1.4 Specification (Per-Fragment
Operations and the Frame Buffer)
......@@ -98,11 +177,20 @@ Errors
INVALID_ENUM is generated by TexImage2D if <format> is MESA_YCBCR but
<internalFormat> is not MESA_YCBCR.
XXX more
INVALID_VALUE is generated by TexImage2D if <format> is MESA_YCBCR and
<internalFormat> is MESA_YCBCR and <border> is not zero.
INVALID_OPERATION is generated by TexSubImage2D if the internal image
format is YCBCR_MESA and format is not YCBCR_MESA.
INVALID_OPERATION is generated by CopyTexSubImage2D if the internal
image is YCBCR_MESA.
New State
None
Edit table 6.16 on page 231: change the type of TEXTURE_INTERNAL_FORMAT
from n x Z42 to n x Z43 to indicate that internal format may also be
YCBCR_MESA.
Revision History
......
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