This commit is contained in:
elwrcl committed 2026-06-06 13:25:15 +03:00
1 parent 04d4dc8b09
commit 818cab85dc
12511 files changed
+6156641

No files matched your search

@@ -0,0 +1,564 @@
Name
MESA_screen_surface
Name Strings
EGL_MESA_screen_surface
Contact
Brian Paul
To discuss, join the [email protected] list.
Status
Obsolete.
Version
11 (27 January 2006)
Number
TBD
Dependencies
EGL 1.0 or later.
Overview
EGL 1.1 supports three types of drawing surfaces:
* Window surfaces
* Pixmap surfaces
* Pbuffer surfaces
This extension defines a fourth type of drawing surface:
* Screen surface
A screen surface is a surface for which the (front) color buffer can
be directly displayed (i.e. scanned out) on a monitor (such as a flat
panel or CRT). In particular the color buffer memory will be allocated
at a location in VRAM (and in a suitable format) which can be displayed
by the graphics hardware.
Note that the width and height of the screen surface need not exactly
match the monitor's current resolution. For example, while the monitor
may be configured to to show 1024x768 pixels, the associated screen
surface may be larger, such as 1200x1000. The "screen origin" attribute
will specify which region of the screen surface which is visible on the
monitor. The screen surface can be scrolled by changing this origin.
This extension also defines functions for controlling the monitor's
display mode (width, height, refresh rate, etc), and specifying which
screen surface is to be displayed on a monitor.
The new EGLModeMESA type and related functions are very similar to the
EGLConfig type and related functions. The user may get a list of
supported modes for a screen and specify the mode to be used when
displaying a screen surface.
Issues
1. Should EGL_INTERLACE be a supported mode attribute?
Arguments against:
No, this should be provided by another extension which would
also provide the mechanisms needed to play back interlaced video
material correctly on hardware that supports it.
This extension should prefer non-interlaced modes. [M. Danzer]
Arguments for:
An interlaced display can be of use without considering video
material. Being able to query whether a screen is operating in
interlaced mode can be used by applications to control their
drawing. For example: avoid drawing 1-pixel-wide horizontal lines
if screen is interlaced. [B. Paul]
Resolution: Defer for future extension?
2. Should EGL_REFRESH_RATE be a supported mode attribute?
Arguments for:
Yes, it's been shown that applications and/or users need to select
modes by this. [M. Danzer]
Many examples have been given in which it's desirable to let the
user choose from a variety of refresh rates without having to
restart/reconfigure. [B. Paul]
Arguments against:
TBD.
Resolution: Yes.
3. Exactly how should the list of modes returned by eglChooseConfigMESA
be sorted?
Current method is described in the text below. Subject to change.
Alternately, leave the sorting order undefined so that each
implementation can return the modes in order of "most desirable"
to "least desirable" which may depend on the display technology
(CRT vs LCD, etc) or other factors.
4. How should screen blanking be supported? Note that a screen can be
disabled or turned off by calling eglShowSurface(dpy, scrn,
EGL_NO_SURFACE, EGL_NO_MODE_MESA). But what about power-save mode?
I would defer this to other extensions that depend on this one.
I can imagine people wanting different semantics not just in
relation to the power management API being exposed (DPMS or whatever)
but also relating to what events can trigger EGL_CONTEXT_LOST. Also
I'm not sure whether power management commands are properly operations
on the Display or on a screen surface. [A. Jackson]
5. Should the EGL_PHYSICAL_SIZE_EGL query be kept? The size information
isn't always reliable (consider video projectors) but can still be
used to determine the pixel aspect ratio.
Resolution: Omit. The EGL 1.2 specification includes queries for
the display resolution and pixel aspect ratio.
6. Should detailed mode timing information be exposed by this API?
Probably not. Instead, offer that information in a layered extension.
7. How should the notion of a screen's "native" mode be expressed?
For example, LCD panels have a native resolution and refresh rate
that looks best but other sub-optimal resolutions may be supported.
The mode attribute EGL_OPTIMAL_MESA will be set for modes which
best match the screen. [M. Danzer]
8. Should eglQueryModeStringMESA() be included? This function returns
a human-readable string which corresponds to an EGLMode.
Arguments for:
A mode name such as "HDTV-720P" might mean more to users than
"1280x720@60Hz" if the later were generated via code.
Arguments against:
There's no standard syntax for the strings. May cause more
trouble than it's worth.
Postpone for future extension. [A. Jackson]
Latest discussion leaning toward omitting this function.
9. Should we use "Get" or "Query" for functions which return state?
The EGL 1.x specification doesn't seem to be totally consistent
in this regard, but "Query" is used more often.
Use "Get" for mode-related queries (as for EGLConfigs) but "Query"
for everything else.
10. What should be the default size for screen surfaces?
For Pbuffer surfaces the default width and height are zero.
We'll do the same for screen surfaces. Since there's no function
to resize surfaces it's useless to have a 0x0 screen, but this isn't
a situation that'll normally be encountered.
11. Should there be a function for resizing a screen surface?
Suppose one wants to change the screen's size in the EGL application.
Also suppose there's a hardware restriction such that only one screen
surface can exist at a time (either for lack of memory or because of
memory layout restrictions).
The basic idea is that the currently displayed screen surface must
be deallocated before a new one can be created. Perhaps a resize
function would work better?
12. How should sub-pixel LCD color information be made available?
What about the display's gamma value?
Perhaps expose as additional read-only mode attributes.
Perhaps postpone for a layered extension.
13. What happens if the user attempts to delete a screen surface that
is currently being shown?
Spec currently says that's illegal and that an error (TBD) will be
generated.
14. What if the physical screen size can't be determined? Should
a query of EGL_PHYSICAL_SIZE_MESA return [0,0]?
Obsolete: EGL_PHYSICAL_SIZE_MESA not used.
15. Suppose the device's number of RAMDACs is different from the
number of output ports. For example, a graphics card with
two RAMDACs but three ports (VGA, DVI, TV).
Address this in a follow-on extension. [Matthias Hopf]
16. How should we deal with on-the-fly device changes? For example,
the monitor being unplugged and replaced by another with different
characteristics?
A HAL event could be received via DBUS in the application [J. Smirl,
A. Jackson].
Should there be an EGL mechanism for detecting this? Maybe an
EGL_SCREEN_LOST error (similar to EGL_CONTEXT_LOST) can be recorded
when there's a screen change. At least then the application can
poll to detect this situation.
Maybe leave that to a future extension.
See also the EGL_SCREEN_COUNT_MESA query.
17. What if pixel-accurate panning is not supported (see
eglScreenPositionMESA)? [M. Danzer]
Is this a common problem? Can we ignore it for now?
18. Should eglShowSurfaceMESA be renamed to eglShowScreenSurfaceMESA?
Probably.
New Procedures and Functions
EGLBoolean eglChooseModeMESA(EGLDisplay dpy, EGLScreenMESA screen,
const EGLint *attrib_list,
EGLModeMESA *modes, EGLint modes_size,
EGLint *num_modes)
EGLBoolean eglGetModesMESA(EGLDisplay dpy, EGLScreenMESA screen,
EGLModeMESA *modes, EGLint modes_size,
EGLint *num_modes)
EGLBoolean eglGetModeAttribMESA(EGLDisplay dpy, EGLModeMESA mode,
EGLint attrib, EGLint *value)
EGLBoolean eglGetScreensMESA(EGLDisplay dpy, EGLScreenMESA *screens,
EGLint screens_size, EGLint *num_screens)
EGLSurface eglCreateScreenSurfaceMESA(EGLDisplay dpy, EGLConfig config,
const EGLint *attrib_list)
EGLBoolean eglShowSurfaceMESA(EGLDisplay dpy, EGLScreenMESA screen,
EGLSurface surface, EGLModeMESA mode)
EGLBoolean eglScreenPositionMESA(EGLDisplay dpy, EGLScreenMESA screen,
EGLint x, EGLint y)
EGLBoolean eglQueryScreenMESA(EGLDisplay dpy, EGLScreenMESA screen,
EGLint attrib, EGLint *value);
EGLBoolean eglQueryScreenSurfaceMESA(EGLDisplay dpy, EGLScreenMESA screen,
EGLSurface *surface)
EGLBoolean eglQueryScreenModeMESA(EGLDisplay dpy, EGLScreenMESA screen,
EGLModeMESA *mode)
const char *eglQueryModeStringMESA(EGLDisplay dpy, EGLMode mode);
New Types
EGLModeMESA
EGLScreenMESA
New Tokens
New error codes:
EGL_BAD_SCREEN_MESA
EGL_BAD_MODE_MESA
Screen-related tokens:
EGL_SCREEN_COUNT_MESA
EGL_SCREEN_POSITION_MESA
EGL_SCREEN_BIT_MESA
EGL_SCREEN_POSITION_GRANULARITY_MESA
Mode-related tokens:
EGL_MODE_ID_MESA
EGL_REFRESH_RATE_MESA
EGL_INTERLACED_MESA
EGL_OPTIMAL_MESA
EGL_NO_MODE_MESA
Additions to Chapter X of the EGL 1.1 Specification
[XXX this all has to be rewritten to fit into the EGL specification
and match the conventions of an EGL extension. For now, just list
all the functions with brief descriptions.]
EGLBoolean eglChooseModeMESA(EGLDisplay dpy, const EGLScreenMESA screen,
EGLint *attrib_list, EGLModeMESA *modes,
EGLint modes_size, EGLint *num_modes)
Like eglChooseConfig, returns a list of EGLModes which match the given
attribute list. This does not set the screen's current display mode.
The attribute list is a list of token/value pairs terminated with
EGL_NONE. Supported attributes include:
Name Description
--------------------- ---------------------------------------------
EGL_WIDTH Mode width (resolution)
EGL_HEIGHT Mode height (resolution)
EGL_REFRESH_RATE_MESA The mode's refresh rate, multiplied by 1000
EGL_INTERLACED_MESA 1 indicates an interlaced mode, 0 otherwise
EGL_OPTIMAL_MESA Set if the most is especially optimal for the
screen (ex. for particular LCD resolutions)
Any other token will generate the error EGL_BAD_ATTRIBUTE.
The list of modes returned by eglChooseModeMESA will be sorted
according to the following criteria. See the discussion of table 3.3
in the EGL specification for more information.
Selection Sort Sort
Attribute Default Criteria Order Priority
-------------------- -------------- ----------- ------ --------
EGL_OPTIMAL_MESA EGL_DONT_CARE Exact 1,0 1
EGL_INTERLACED_MESA EGL_DONT_CARE Exact 0,1 2
EGL_REFRESH_RATE EGL_DONT_CARE AtLeast Larger 3
EGL_WIDTH EGL_DONT_CARE AtLeast Larger 4
EGL_HEIGHT EGL_DONT_CARE AtLeast Larger 5
EGL_MODE_ID_MESA EGL_DONT_CARE Exact Smaller 6
EGLBoolean eglGetModesMESA(EGLDisplay dpy, EGLScreenMESA screen,
EGLModeMESA *modes, EGLint modes_size,
EGLint *num_modes)
Like eglGetConfigs, returns a list of all modes supported by the
given screen. The returned modes will be sorted in the same manner
as for eglChooseModeMESA().
EGLBoolean eglGetModeAttribMESA(EGLDisplay dpy, EGLModeMESA mode,
EGLint attrib, EGLint *value)
Used to query mode attributes. The following attributes are supported:
Name Return value description
--------------------- ----------------------------------------------
EGL_OPTIMAL_MESA 1 indicates an optimal mode, 0 otherwise
EGL_INTERLACED_MESA 1 indicates an interlaced mode, 0 otherwise
EGL_REFRESH_RATE_MESA The mode's refresh rate, multiplied by 1000
EGL_WIDTH Mode width (resolution)
EGL_HEIGHT Mode height (resolution)
EGL_MODE_ID_MESA A unique small integer identifier for the mode
Any other token will generate the error EGL_BAD_ATTRIBUTE.
EGLBoolean eglGetScreensMESA(EGLDisplay dpy, EGLScreenMESA *screens,
EGLint screens_size, EGLint *num_screens)
This function returns an array of all available screen handles.
<screens_size> is the maximum number of screens to return in the
<screens> array. <num_screens> will return the number of screen handles
placed in the array, even if <screens> is NULL.
The number of screens and the availability of each may change over
time (hot-plugging). Screen handles will not be reused. When a
screen handle becomes invalid, function calls which reference an
invalid handle will generate EGL_BAD_SCREEN_MESA.
The first screen handle returned will be considered to be the primary
one.
EGLSurface eglCreateScreenSurfaceMESA(EGLDisplay dpy, EGLConfig config,
const EGLint *attrib_list)
Create a surface that can be displayed on a screen. <attrib_list> is
an array of token/value pairs terminated with EGL_NONE. Valid tokens
include:
Name Description
---------------- --------------------------------
EGL_WIDTH desired surface width in pixels
EGL_HEIGHT desired surface height in pixels
Any other token will generate the error EGL_BAD_ATTRIBUTE.
The default width and height are zero.
EGLBoolean eglShowSurfaceMESA(EGLDisplay dpy, EGLScreenMESA screen,
EGLSurface surface, EGLModeMESA mode)
This function causes a screen to show the given surface (or more
precisely, the surface's front color buffer) with the given mode.
If the surface is in any way incompatible with the mode, the error
EGL_BAD_MATCH will be generated, EGL_FALSE will be returned, and the
previous screen state will remain in effect. This might occur when
the bandwidth of the video-out subsystem is exceeded, or if the mode
specifies a width or height that's greater than the width or height
of the surface.
To disable a screen, the values EGL_NO_SURFACE and EGL_NO_MODE_MESA
be passed as the <surface> and <mode> parameters.
The values of EGL_SCREEN_POSITION_MESA are clamped to the new valid
range computed from the screen size and surface size. If the new
surface is EGL_NO_SURFACE, EGL_SCREEN_POSITION_MESA is set to [0, 0].
Attempting to delete a screen surface which is currently being
displayed will result in the error EGL_BAD_ACCESS being generated.
EGLBoolean eglScreenPositionMESA(EGLDisplay dpy, EGLScreenMESA screen,
EGLint x, EGLint y)
Specifies the origin of the screen's view into the surface, if the
surface is larger than the screen. Valid values for x and y are
[0, surfaceWidth - screenWidth] and [0, surfaceHeight - screenHeight],
respectively.
The x and y values are also constrained to be integer multiples of the
EGL_SCREEN_POSITION_GRANULARITY_MESA values.
EGLBoolean eglQueryScreenMESA(EGLDisplay dpy, EGLScreenMESA screen,
EGLint attrib, EGLint *value);
Used to query screen attributes. <attrib> may be one of the following:
Name Return value description
------------------------ ---------------------------------------------
EGL_SCREEN_POSITION_MESA x, y position of the screen's origin with
respect to the surface. If no surface is
attached to the screen, [0, 0] is returned.
EGL_SCREEN_POSITION_GRANULARITY_MESA
Returns the granularity, in pixels, for
which the screen position is constrained.
Any other token will generate the error EGL_BAD_ATTRIBUTE.
EGLBoolean eglQueryScreenSurfaceMESA(EGLDisplay dpy, EGLScreenMESA screen,
EGLSurface *surface)
Returns the surface currently displayed on the given screen. <surface>
may be EGL_NO_SURFACE if the screen isn't currently showing any surface.
EGLBoolean eglQueryScreenModeMESA(EGLDisplay dpy, EGLScreenMESA screen,
EGLModeMESA *mode)
Returns the given screen's current display mode. The mode may be
EGL_NO_MODE_MESA if the screen is currently disabled.
const char *eglQueryModeStringMESA(EGLDisplay dpy, EGLModeMESA mode);
Returns a human-readable string for the given mode. The string is a
zero-terminated C string which the user should not attempt to free.
There is no standard syntax for mode strings. Applications should
not directly rely on mode strings.
Version History
1. 15 March 2005 - BrianP
Initial version
2. 16 March 2005 - BrianP
Removed EGL_DEPTH_MESA
Added EGL_PHYSICAL_WIDTH_MESA, EGL_PHYSICAL_HEIGHT_MESA queries
Added EGL_OPTIMAL_MESA for width/height/refresh rate selection
Added possible eglQueryModeStringMESA() function
More details of the new functions explained.
3. 18 March 2005 - BrianP
Added screen_number to eglChooseModeMESA().
Fix off by one mistake in value range for ORIGIN attributes
Added Issues section
4. 21 March 2005 - BrianP
Removed eglScreenAttribsMESA().
Added eglScreenPositionMESA() to set screen origin.
Replaced EGL_SCREEN_X/Y_OFFSET_MESA with EGL_SCREEN_POSITION_MESA.
Replaced EGL_PHYSICAL_WIDTH/HEIGHT_MESA with EGL_PHYSICAL_SIZE_MESA.
Use EGL_OPTIMAL_MESA as a new mode attribute. (Michel Danzer)
Added a few more issues.
5. 6 April 2005 - BrianP
More language for eglGetModeStringMESA().
Added issues 10, 11, 12, 13, 14.
Updated issue 3 discussion about mode sorting.
6. 22 April 2005 - BrianP
Fixed "LDC" typo.
Added issues 15, 16.
Changed dependency on EGL 1.1 to EGL 1.0
s/EGL_NUM_SCREENS_MESA/EGL_SCREEN_COUNT_MESA/
Added eglQueryDisplayMESA() to New Functions section.
Clarified language for the EGL_SCREEN_COUNT_MESA query.
7. 29 April 2005 - BrianP
Added EGLScreenMESA type and eglGetScreensMESA() function. [J. Smirl].
Replaced EGLint screen_number parameters with EGLScreenMESA screen.
Added issue 17 (pixel-accurate panning)
8. 2 May 2005 - BrianP
Removed eglQueryDisplayMESA.
Fixed a few more EGLint -> EGLScreenMESA changes.
9. 20 May 2005 - BrianP
Fixed a few typos.
Updated some open issues text.
10. 10 August 2005 - BrianP
Added EGL_SCREEN_POSITION_GRANULARITY_MESA.
11. 27 January 2006 - BrianP
EGL_PHYSICAL_SIZE_MESA removed since EGL 1.2 has a similar feature.
@@ -0,0 +1,94 @@
Name
MESA_agp_offset
Name Strings
GLX_MESA_agp_offset
Contact
Brian Paul, Tungsten Graphics, Inc. (brian.paul 'at' tungstengraphics.com)
Keith Whitwell, Tungsten Graphics, Inc. (keith 'at' tungstengraphics.com)
Status
Obsolete. Effectively superseded by ARB_vertex_buffer_object.
Version
1.0
Number
TBD
Dependencies
OpenGL 1.0 or later is required
GLX_NV_vertex_array_range is required.
This extensions is written against the OpenGL 1.4 Specification.
Overview
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
None
Issues
None
New Procedures and Functions
unsigned int glXGetAGPOffsetMESA( const void *pointer )
New Tokens
None
Additions to the OpenGL 1.4 Specification
None
Additions to Chapter 3 the GLX 1.4 Specification (Functions and Errors)
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
aperture. 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
None. This is a client side-only extension.
Errors
glXGetAGPOffsetMESA will return ~0 if the pointer does not point to
an AGP memory region.
New State
None
Revision History
20 September 2002 - Initial draft
2 October 2002 - finished GLX chapter 3 additions
27 July 2004 - use unsigned int instead of GLuint, void instead of GLvoid
@@ -0,0 +1,158 @@
Name
MESA_multithread_makecurrent
Name Strings
GLX_MESA_multithread_makecurrent
Contact
Eric Anholt ([email protected])
Status
Obsolete.
Version
Last Modified Date: 21 February 2011
Number
TBD
Dependencies
OpenGL 1.0 or later is required.
GLX 1.3 or later is required.
Overview
The GLX context setup encourages multithreaded applications to
create a context per thread which each operate on their own
objects in parallel, and leaves synchronization for write access
to shared objects up to the application.
For some applications, maintaining per-thread contexts and
ensuring that the glFlush happens in one thread before another
thread starts working on that object is difficult. For them,
using the same context across multiple threads and protecting its
usage with a mutex is both higher performance and easier to
implement. This extension gives those applications that option by
relaxing the context binding requirements.
This new behavior matches the requirements of AGL, while providing
a feature not specified in WGL.
IP Status
Open-source; freely implementable.
Issues
None.
New Procedures and Functions
None.
New Tokens
None.
Changes to Chapter 2 of the GLX 1.3 Specification (Functions and Errors)
Replace the following sentence from section 2.2 Rendering Contexts:
In addition, a rendering context can be current for only one
thread at a time.
with:
In addition, an indirect rendering context can be current for
only one thread at a time. A direct rendering context may be
current to multiple threads, with synchronization of access to
the context through the GL managed by the application through
mutexes.
Changes to Chapter 3 of the GLX 1.3 Specification (Functions and Errors)
Replace the following sentence from section 3.3.7 Rendering Contexts:
If ctx is current to some other thread, then
glXMakeContextCurrent will generate a BadAccess error.
with:
If ctx is an indirect context current to some other thread,
then glXMakeContextCurrent will generate a BadAccess error.
Replace the following sentence from section 3.5 Rendering Contexts:
If ctx is current to some other thread, then
glXMakeCurrent will generate a BadAccess error.
with:
If ctx is an indirect context current to some other thread,
then glXMakeCurrent will generate a BadAccess error.
GLX Protocol
None. The GLX extension only extends to direct rendering contexts.
Errors
None.
New State
None.
Issues
(1) What happens if the app binds a context/drawable in multiple
threads, then binds a different context/thread in one of them?
As with binding a new context from the current thread, the old
context's refcount is reduced and the new context's refcount is
increased.
(2) What happens if the app binds a context/drawable in multiple
threads, then binds None/None in one of them?
The GLX context is unreferenced from that thread, and the other
threads retain their GLX context binding.
(3) What happens if the app binds a context/drawable in 7 threads,
then destroys the context in one of them?
As with GLX context destruction previously, the XID is destroyed
but the context remains usable by threads that have the context
current.
(4) What happens if the app binds a new drawable/readable with
glXMakeCurrent() when it is already bound to another thread?
The context becomes bound to the new drawable/readable, and
further rendering in either thread will use the new
drawable/readable.
(5) What requirements should be placed on the user managing contexts
from multiple threads?
The intention is to allow multithreaded access to the GL at the
minimal performance cost, so requiring that the GL do general
synchronization (beyond that already required by context sharing)
is not an option, and synchronizing of GL's access to the GL
context between multiple threads is left to the application to do
across GL calls. However, it would be unfortunate for a library
doing multithread_makecurrent to require that other libraries
share in synchronization for binding of their own contexts, so the
refcounting of the contexts is required to be threadsafe.
(6) Does this apply to indirect contexts?
This was ignored in the initial revision of the spec. Behavior
for indirect contexts is left as-is.
Revision History
20 November 2009 Eric Anholt - initial specification
22 November 2009 Eric Anholt - added issues from Ian Romanick.
3 February 2011 Eric Anholt - updated with resolution to issues 1-3
3 February 2011 Eric Anholt - added issue 4, 5
21 February 2011 Eric Anholt - Include glXMakeCurrent() sentence
along with glXMakeContextCurrent() for removal.
@@ -0,0 +1,230 @@
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
Obsolete.
Version
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.
@@ -0,0 +1,356 @@
Name
MESA_program_debug
Name Strings
GL_MESA_program_debug
Contact
Brian Paul (brian.paul 'at' tungstengraphics.com)
Status
Obsolete.
Version
Last Modified Date: July 20, 2003
Author Revision: 1.0
Number
TBD
Dependencies
OpenGL 1.4 is required
The extension is written against the OpenGL 1.4 specification.
ARB_vertex_program or ARB_fragment_program or NV_vertex_program
or NV_fragment_program is required.
Overview
The extension provides facilities for implementing debuggers for
vertex and fragment programs.
The concept is that vertex and fragment program debuggers will be
implemented outside of the GL as a utility package. This extension
only provides the minimal hooks required to implement a debugger.
There are facilities to do the following:
1. Have the GL call a user-specified function prior to executing
each vertex or fragment instruction.
2. Query the current program string's execution position.
3. Query the current values of intermediate program values.
The main feature is the ProgramCallbackMESA function. It allows the
user to register a callback function with the GL. The callback will
be called prior to executing each vertex or fragment program instruction.
From within the callback, the user may issue Get* commands to
query current GL state. The GetProgramRegisterfvMESA function allows
current program values to be queried (such as temporaries, input
attributes, and result registers).
There are flags for enabling/disabling the program callbacks.
The current execution position (as an offset from the start of the
program string) can be queried with
GetIntegerv(GL_FRAGMENT_PROGRAM_POSITION_MESA, &pos) or
GetIntegerv(GL_VERTEX_PROGRAM_POSITION_MESA, &pos).
IP Status
None
Issues
1. Is this the right model for a debugger?
It seems prudent to minimize the scope of this extension and leave
it up to the developer (or developer community) to write debuggers
that layer on top of this extension.
If the debugger were fully implemented within the GL it's not
clear how terminal and GUI-based interfaces would work, for
example.
2. There aren't any other extensions that register callbacks with
the GL. Isn't there another solution?
If we want to be able to single-step through vertex/fragment
programs I don't see another way to do it.
3. How do we prevent the user from doing something crazy in the
callback function, like trying to call glBegin (leading to
recursion)?
The rule is that the callback function can only issue glGet*()
functions and no other GL commands. It could be difficult to
enforce this, however. Therefore, calling any non-get GL
command from within the callback will result in undefined
results.
4. Is this extension amenable to hardware implementation?
Hopefully, but if not, the GL implementation will have to fall
back to a software path when debugging. This may be acceptable
for debugging.
5. What's the <data> parameter to ProgramCallbackMESA for?
It's a common programming practice to associate a user-supplied
value with callback functions.
6. Debuggers often allow one to modify intermediate program values,
then continue. Does this extension support that?
No.
New Procedures and Functions (and datatypes)
typedef void (*programcallbackMESA)(enum target, void *data)
void ProgramCallbackMESA(enum target, programcallbackMESA callback,
void *data)
void GetProgramRegisterfvMESA(enum target, sizei len,
const ubyte *registerName, float *v)
New Tokens
Accepted by the <cap> parameter of Enable, Disable, IsEnabled,
GetBooleanv, GetDoublev, GetFloatv and GetIntegerv:
FRAGMENT_PROGRAM_CALLBACK_MESA 0x8bb1
VERTEX_PROGRAM_CALLBACK_MESA 0x8bb4
Accepted by the <pname> parameter GetBooleanv, GetDoublev,
GetFloatv and GetIntegerv:
FRAGMENT_PROGRAM_POSITION_MESA 0x8bb0
VERTEX_PROGRAM_POSITION_MESA 0x8bb5
Accepted by the <pname> parameter of GetPointerv:
FRAGMENT_PROGRAM_CALLBACK_FUNC_MESA 0x8bb2
FRAGMENT_PROGRAM_CALLBACK_DATA_MESA 0x8bb3
VERTEX_PROGRAM_CALLBACK_FUNC_MESA 0x8bb6
VERTEX_PROGRAM_CALLBACK_DATA_MESA 0x8bb7
Additions to Chapter 2 of the OpenGL 1.4 Specification (OpenGL Operation)
None.
Additions to Chapter 3 of the OpenGL 1.4 Specification (Rasterization)
None.
Additions to Chapter 4 of the OpenGL 1.4 Specification (Per-Fragment
Operations and the Frame Buffer)
None.
Additions to Chapter 5 of the OpenGL 1.4 Specification (Special Functions)
In section 5.4 "Display Lists", page 202, add the following command
to the list of those that are not compiled into display lists:
ProgramCallbackMESA.
Add a new section 5.7 "Callback Functions"
The function
void ProgramCallbackMESA(enum target, programcallbackMESA callback,
void *data)
registers a user-defined callback function with the GL. <target>
may be FRAGMENT_PROGRAM_ARB or VERTEX_PROGRAM_ARB. The enabled
callback functions registered with these targets will be called
prior to executing each instruction in the current fragment or
vertex program, respectively. The callbacks are enabled and
disabled by calling Enable or Disable with <cap>
FRAGMENT_PROGRAM_ARB or VERTEX_PROGRAM_ARB.
The callback function's signature must match the typedef
typedef void (*programcallbackMESA)(enum target, void *data)
When the callback function is called, <target> will either be
FRAGMENT_PROGRAM_ARB or VERTEX_PROGRAM_ARB to indicate which
program is currently executing and <data> will be the value
specified when ProgramCallbackMESA was called.
From within the callback function, only the following GL commands
may be called:
GetBooleanv
GetDoublev
GetFloatv
GetIntegerv
GetProgramLocalParameter
GetProgramEnvParameter
GetProgramRegisterfvMESA
GetProgramivARB
GetProgramStringARB
GetError
Calling any other command from within the callback results in
undefined behaviour.
Additions to Chapter 6 of the OpenGL 1.4 Specification (State and
State Requests)
Add a new section 6.1.3 "Program Value Queries":
The command
void GetProgramRegisterfvMESA(enum target, sizei len,
const ubyte *registerName,
float *v)
Is used to query the value of program variables and registers
during program execution. GetProgramRegisterfvMESA may only be
called from within a callback function registered with
ProgramCallbackMESA.
<registerName> and <len> specify the name a variable, input
attribute, temporary, or result register in the program string.
The current value of the named variable is returned as four
values in <v>. If <name> doesn't exist in the program string,
the error INVALID_OPERATION is generated.
Additions to Appendix A of the OpenGL 1.4 Specification (Invariance)
None.
Additions to the AGL/GLX/WGL Specifications
None.
GLX Protocol
XXX TBD
Dependencies on NV_vertex_program and NV_fragment_program
If NV_vertex_program and/or NV_fragment_program are supported,
vertex and/or fragment programs defined by those extensions may
be debugged as well. Register queries will use the syntax used
by those extensions (i.e. "v[X]" to query vertex attributes,
"o[X]" for vertex outputs, etc.)
Errors
INVALID_OPERATION is generated if ProgramCallbackMESA is called
between Begin and End.
INVALID_ENUM is generated by ProgramCallbackMESA if <target> is not
a supported vertex or fragment program type.
Note: INVALID_OPERAION IS NOT generated by GetProgramRegisterfvMESA,
GetBooleanv, GetDoublev, GetFloatv, or GetIntegerv if called between
Begin and End when a vertex or fragment program is currently executing.
INVALID_ENUM is generated by ProgramCallbackMESA,
GetProgramRegisterfvMESA if <target> is not a program target supported
by ARB_vertex_program, ARB_fragment_program (or NV_vertex_program or
NV_fragment_program).
INVALID_VALUE is generated by GetProgramRegisterfvMESA if <registerName>
does not name a known program register or variable.
INVALID_OPERATION is generated by GetProgramRegisterfvMESA when a
register query is attempted for a program target that's not currently
being executed.
New State
XXX finish
(table 6.N, p. ###)
Initial
Get Value Type Get Command Value Description Sec. Attribute
--------- ---- ----------- ----- ----------- ---- ---------
FRAGMENT_PROGRAM_CALLBACK_MESA B IsEnabled FALSE XXX XXX enable
VERTEX_PROGRAM_CALLBACK_MESA B IsEnabled FALSE XXX XXX enable
FRAGMENT_PROGRAM_POSITION_MESA Z+ GetIntegerv -1 XXX XXX -
VERTEX_PROGRAM_POSITION_MESA Z+ GetIntegerv -1 XXX XXX -
FRAGMENT_PROGRAM_CALLBACK_FUNC_MESA P GetPointerv NULL XXX XXX -
VERTEX_PROGRAM_CALLBACK_FUNC_MESA P GetPointerv NULL XXX XXX -
FRAGMENT_PROGRAM_CALLBACK_DATA_MESA P GetPointerv NULL XXX XXX -
VERTEX_PROGRAM_CALLBACK_DATA_MESA P GetPointerv NULL XXX XXX -
XXX more?
New Implementation Dependent State
None.
Revision History
8 July 2003
Initial draft. (Brian Paul)
11 July 2003
Second draft. (Brian Paul)
20 July 2003
Third draft. Lots of fundamental changes. (Brian Paul)
23 July 2003
Added chapter 5 and 6 spec language. (Brian Paul)
Example Usage
The following is a very simple example of how this extension may
be used to print the values of R0, R1, R2 and R3 while executing
vertex programs.
/* This is called by the GL when the vertex program is executing.
* We can only make glGet* calls from within this function!
*/
void DebugCallback(GLenum target, GLvoid *data)
{
GLint pos;
GLuint i;
/* Get PC and current instruction string */
glGetIntegerv(GL_VERTEX_PROGRAM_POSITION_ARB, &pos);
printf("Current position: %d\n", pos);
printf("Current temporary registers:\n");
for (i = 0; i < 4; i++) {
GLfloat v[4];
char s[10];
sprintf(s, "R%d", i);
glGetProgramRegisterfvMESA(GL_VERTEX_PROGRAM_ARB, strlen(s), s, v);
printf("R%d = %g, %g, %g, %g\n", i, v[0], v[1], v[2], v[3]);
}
}
/*
* elsewhere...
*/
/* Register our debugger callback function */
glProgramCallbackMESA(GL_VERTEX_PROGRAM_ARB, DebugCallback, NULL);
glEnable(GL_VERTEX_PROGRAM_CALLBACK_MESA);
/* define/bind a vertex program */
glEnable(GL_VERTEX_PROGRAM);
/* render something */
glBegin(GL_POINTS);
glVertex2f(0, 0);
glEnd();
@@ -0,0 +1,81 @@
Name
MESA_resize_buffers
Name Strings
GL_MESA_resize_buffers
Contact
Brian Paul (brian.paul 'at' tungstengraphics.com)
Status
Obsolete.
Version
Number
196
Dependencies
Mesa 2.2 or later is required.
Overview
Mesa is often used as a client library with no integration with
the computer's window system (an X server, for example). And since
Mesa does not have an event loop nor window system callbacks, it
cannot properly respond to window system events. In particular,
Mesa cannot automatically detect when a window has been resized.
Mesa's glViewport command queries the current window size and updates
its internal data structors accordingly. This normally works fine
since most applications call glViewport in response to window size
changes.
In some situations, however, the application may not call glViewport
when a window size changes but would still like Mesa to adjust to
the new window size. This extension exports a new function to solve
this problem.
New Procedures and Functions
void glResizeBuffersMESA( void )
New Tokens
none
Additions to the OpenGL Specification (no particular section)
The glResizeBuffersMESA command may be called when the client
determines that a window has been resized. Calling
glResizeBuffersMESA causes Mesa to query the current window size
and adjust its internal data structures. This may include
reallocating depth, stencil, alpha and accumulation buffers.
Additions to the AGL/GLX/WGL Specifications
None
Errors
INVALID_OPERATION is generated if glResizeBuffersMESA is called between
Begin and End.
New State
None.
New Implementation Dependent State
None.
Revision History
* Revision 1.0 - Initial specification
@@ -0,0 +1,85 @@
Name
MESA_set_3dfx_mode
Name Strings
GLX_MESA_set_3dfx_mode
Contact
Brian Paul (brian.paul 'at' tungstengraphics.com)
Status
Obsolete.
Version
Last Modified Date: 8 June 2000
Number
218
Dependencies
OpenGL 1.0 or later is required.
GLX 1.0 or later is required.
Overview
The Mesa Glide driver allows full-screen rendering or rendering into
an X window. The glXSet3DfxModeMESA() function allows an application
to switch between full-screen and windowed rendering.
IP Status
Open-source; freely implementable.
Issues
None.
New Procedures and Functions
GLboolean glXSet3DfxModeMESA( GLint mode );
New Tokens
GLX_3DFX_WINDOW_MODE_MESA 0x1
GLX_3DFX_FULLSCREEN_MODE_MESA 0x2
Additions to Chapter 3 of the GLX 1.3 Specification (Functions and Errors)
The Mesa Glide device driver allows either rendering in full-screen
mode or rendering into an X window. An application can switch between
full-screen and window rendering with the command:
GLboolean glXSet3DfxModeMESA( GLint mode );
<mode> may either be GLX_3DFX_WINDOW_MODE_MESA to indicate window
rendering or GLX_3DFX_FULLSCREEN_MODE_MESA to indicate full-screen mode.
GL_TRUE is returned if <mode> is valid and the operation completed
normally. GL_FALSE is returned if <mode> is invalid or if the Glide
driver is not being used.
Note that only one drawable and context can be created at any given
time with the Mesa Glide driver.
GLX Protocol
None since this is a client-side extension.
Errors
None.
New State
None.
Revision History
8 June 2000 - initial specification
@@ -0,0 +1,264 @@
Name
MESA_shader_debug
Name Strings
GL_MESA_shader_debug
Contact
Brian Paul (brian.paul 'at' tungstengraphics.com)
Michal Krol (mjkrol 'at' gmail.com)
Status
Obsolete.
Version
Last Modified Date: July 30, 2006
Author Revision: 0.2
Number
TBD
Dependencies
OpenGL 1.0 is required.
The ARB_shader_objects extension is required.
The ARB_shading_language_100 extension is required.
The extension is written against the OpenGL 1.5 specification.
The extension is written against the OpenGL Shading Language 1.10
Specification.
Overview
This extension introduces a debug object that can be attached to
a program object to enable debugging. Vertex and/or fragment shader,
during execution, issue diagnostic function calls that are logged
to the debug object's log. A separate debug log for each shader type
is maintained. A debug object can be attached, detached and queried
at any time outside the Begin/End pair. Multiple debug objects can
be attached to a single program object.
IP Status
None
Issues
None
New Procedures and Functions
handleARB CreateDebugObjectMESA(void)
void ClearDebugLogMESA(handleARB obj, enum logType, enum shaderType)
void GetDebugLogMESA(handleARB obj, enum logType, enum shaderType,
sizei maxLength, sizei *length,
charARB *debugLog)
sizei GetDebugLogLengthMESA(handleARB obj, enum logType,
enum shaderType)
New Types
None
New Tokens
Returned by the <params> parameter of GetObjectParameter{fi}vARB:
DEBUG_OBJECT_MESA 0x8759
Accepted by the <logType> argument of ClearDebugLogMESA,
GetDebugLogLengthMESA and GetDebugLogMESA:
DEBUG_PRINT_MESA 0x875A
DEBUG_ASSERT_MESA 0x875B
Additions to Chapter 2 of the OpenGL 1.5 Specification
(OpenGL Operation)
None
Additions to Chapter 3 of the OpenGL 1.5 Specification (Rasterization)
None
Additions to Chapter 4 of the OpenGL 1.5 Specification (Per-Fragment
Operations and the Frame Buffer)
None
Additions to Chapter 5 of the OpenGL 1.5 Specification
(Special Functions)
None
Additions to Chapter 6 of the OpenGL 1.5 Specification (State and State
Requests)
None
Additions to Appendix A of the OpenGL 1.5 Specification (Invariance)
None
Additions to Chapter 1 of the OpenGL Shading Language 1.10 Specification
(Introduction)
None
Additions to Chapter 2 of the OpenGL Shading Language 1.10 Specification
(Overview of OpenGL Shading)
None
Additions to Chapter 3 of the OpenGL Shading Language 1.10 Specification
(Basics)
None
Additions to Chapter 4 of the OpenGL Shading Language 1.10 Specification
(Variables and Types)
None
Additions to Chapter 5 of the OpenGL Shading Language 1.10 Specification
(Operators and Expressions)
None
Additions to Chapter 6 of the OpenGL Shading Language 1.10 Specification
(Statements and Structure)
None
Additions to Chapter 7 of the OpenGL Shading Language 1.10 Specification
(Built-in Variables)
None
Additions to Chapter 8 of the OpenGL Shading Language 1.10 Specification
(Built-in Functions)
Add a new section 8.10 "Debug Functions":
Debug functions are available to both fragment and vertex shaders.
They are used to track the execution of a shader by logging
passed-in arguments to the debug object's log. Those values can be
retrieved by the application for inspection after shader execution
is complete.
The text, if any, produced by any of these functions is appended
to each debug object that is attached to the program object.
There are different debug log types
Add a new section 8.10.1 "Print Function":
The following printMESA prototypes are available.
void printMESA(const float value)
void printMESA(const int value)
void printMESA(const bool value)
void printMESA(const vec2 value)
void printMESA(const vec3 value)
void printMESA(const vec4 value)
void printMESA(const ivec2 value)
void printMESA(const ivec3 value)
void printMESA(const ivec4 value)
void printMESA(const bvec2 value)
void printMESA(const bvec3 value)
void printMESA(const bvec4 value)
void printMESA(const mat2 value)
void printMESA(const mat3 value)
void printMESA(const mat4 value)
void printMESA(const sampler1D value)
void printMESA(const sampler2D value)
void printMESA(const sampler3D value)
void printMESA(const samplerCube value)
void printMESA(const sampler1DShadow value)
void printMESA(const sampler2DShadow value)
The printMESA function writes the argument <value> to the "debug
print log" (XXX DEBUG_PRINT_MESA?). Each component is written in
text format (XXX format!) and is delimited by a white space (XXX 1
or more?).
Add a new section 8.10.2 "Assert Function":
The following assertMESA prototypes are available.
void assertMESA(const bool condition)
void assertMESA(const bool condition, const int cookie)
void assertMESA(const bool condition, const int cookie,
const int file, const int line)
The assertMESA function checks if the argument <condition> is
true or false. If it is true, nothing happens. If it is false,
a diagnostic message is written to the "debug assert log".
The message contains the argument <file>, <line>, <cookie> and
implementation dependent double-quoted string, each of this
delimited by a white space. If the argument <cookie> is not present,
it is meant as if it was of value 0. If the arguments <file> and
<line> are not present, they are meant as if they were of values
__FILE__ and __LINE__, respectively. The following three calls
produce the same output, assuming they were issued from the same
file and line.
assertMESA (false);
assertMESA (false, 0);
assertMESA (false, 0, __FILE__, __LINE__);
The diagnostic message examples follow.
1 89 0 ""
1 45 333 "all (lessThanEqual (fragColor, vec4 (1.0)))"
1 66 1 "assertion failed in file 1, line 66, cookie 1"
Additions to Chapter 9 of the OpenGL Shading Language 1.10 Specification
(Shading Language Grammar)
None
Additions to Chapter 10 of the OpenGL Shading Language 1.10
Specification (Issues)
None
Additions to the AGL/EGL/GLX/WGL Specifications
None
GLX Protocol
None
Errors
TBD
New State
TBD
New Implementation Dependent State
TBD
Sample Code
TBD
Revision History
29 May 2006
Initial draft. (Michal Krol)
30 July 2006
Add Overview, New Procedures and Functions, New Tokens sections.
Add sections 8.10.1, 8.10.2 to GLSL spec.
@@ -0,0 +1,190 @@
Name
MESA_sprite_point
Name Strings
GL_MESA_sprite_point
Contact
Brian Paul, VA Linux Systems Inc. (brianp 'at' valinux.com)
Status
Obsolete - see GL_ARB_point_sprite.
Version
Number
???
Dependencies
GL_EXT_point_parameters effects the definition of this extension
GL_ARB_multitexture effects the definition of this extension
Overview
This extension modifies the way in which points are rendered,
specifically when they're textured. When SPRITE_POINT_MESA is enabled
a point is rendered as if it were a quadrilateral with unique texture
coordinates at each vertex. This extension effectively turns points
into sprites which may be rendered more easily and quickly than using
conventional textured quadrilaterals.
When using point size > 1 or attenuated points this extension is an
effective way to render many small sprite images for particle systems
or other effects.
Issues:
1. How are the texture coordinates computed?
The lower-left corner has texture coordinate (0,0,r,q).
The lower-right, (1,0,r,q). The upper-right, (1,1,r,q).
The upper-left, (0,1,r,q).
2. What about texgen and texture matrices?
Texgen and the texture matrix have no effect on the point's s and t
texture coordinates. The r and q coordinates may have been computed
by texgen or the texture matrix. Note that with a 3D texture and/or
texgen that the r coordinate could be used to select a slice in the
3D texture.
3. What about point smoothing?
When point smoothing is enabled, a triangle fan could be rendered
to approximate a circular point. This could be problematic to
define and implement so POINT_SMOOTH is ignored when drawing sprite
points.
Smoothed points can be approximated by using an appropriate texture
images, alpha testing and blending.
POLYGON_SMOOTH does effect the rendering of the quadrilateral, however.
4. What about sprite rotation?
There is none. Sprite points are always rendered as window-aligned
squares. One could define rotated texture images if desired. A 3D
texture and appropriate texture r coordinates could be used to
effectively specify image rotation per point.
5. What about POLYGON_MODE?
POLYGON_MODE does not effect the rasterization of the quadrilateral.
6. What about POLYGON_CULL?
TBD. Polygon culling is normally specified and implemented in the
transformation stage of OpenGL. However, some rasterization hardware
implements it later during triangle setup.
Polygon culling wouldn't be useful for sprite points since the
quadrilaterals are always defined in counter-clockwise order in
window space. For that reason, polygon culling should probably be
ignored.
7. Should sprite points be alpha-attenuated if their size is below the
point parameter's threshold size?
8. Should there be an advertisized maximum sprite point size?
No. Since we're rendering the point as a quadrilateral there's no
need to limit the size.
New Procedures and Functions
None.
New Tokens
Accepted by the <pname> parameter of Enable, Disable, IsEnabled,
GetIntegerv, GetBooleanv, GetFloatv and GetDoublev:
SPRITE_POINT_MESA 0x????
MAX_SPRITE_POINT_SIZE_MESA 0x???? (need this?)
Additions to Chapter 2 of the 1.1 Specification (OpenGL Operation)
None
Additions to Chapter 3 of the 1.1 Specification (Rasterization)
Section ???.
When SPRITE_POINT_MESA is enabled points are rasterized as screen-
aligned quadrilaterals. If the four vertices of the quadrilateral
are labeled A, B, C, and D, starting at the lower-left corner and moving
counter-clockwise around the quadrilateral, then the vertex and
texture coordinates are computed as follows:
vertex window coordinate texture coordinate
A (x-r, y-r, z, w) (0, 0, r, q)
B (x+r, y-r, z, w) (1, 0, r, q)
C (x+r, y+r, z, w) (1, 1, r, q)
D (x-r, y+r, z, w) (0, 1, r, q)
where x, y, z, w are the point's window coordinates, r and q are the
point's 3rd and 4th texture coordinates and r is half the point's
size. The other vertex attributes (such as the color and fog coordinate)
are simply duplicated from the original point vertex.
Point size may either be specified with PointSize or computed
according to the EXT_point_parameters extension.
The new texture coordinates are not effected by texgen or the texture
matrix. Note, however, that the texture r and q coordinates are passed
unchanged and may have been computed with texgen and/or the texture
matrix.
If multiple texture units are present the same texture coordinate is
used for all texture units.
The point is then rendered as if it were a quadrilateral using the
normal point sampling rules. POLYGON_MODE does not effect the
rasterization of the quadrilateral but POLYGON_SMOOTH does.
POINT_SMOOTH has no effect when SPRITE_POINT_MESA is enabled.
Additions to Chapter 4 of the 1.1 Specification (Per-Fragment Operations
and the Frame Buffer)
None.
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
Add boolean variable SPRITE_POINT_MESA to the point attribute group.
Revision History
Version 1.0 - 4 Dec 2000
Original draft.
@@ -0,0 +1,201 @@
Name
MESA_swap_frame_usage
Name Strings
GLX_MESA_swap_frame_usage
Contact
Ian Romanick, IBM, idr at us.ibm.com
Status
Obsolete.
Version
Date: 5/1/2003 Revision: 1.1
Number
???
Dependencies
GLX_SGI_swap_control affects the definition of this extension.
GLX_MESA_swap_control affects the definition of this extension.
GLX_OML_sync_control affects the definition of this extension.
Based on WGL_I3D_swap_frame_usage version 1.3.
Overview
This extension allows an application to determine what portion of the
swap period has elapsed since the last swap operation completed. The
"usage" value is a floating point value on the range [0,max] which is
calculated as follows:
td
percent = ----
tf
where td is the time measured from the last completed buffer swap (or
call to enable the statistic) to when the next buffer swap completes, tf
is the entire time for a frame which may be multiple screen refreshes
depending on the swap interval as set by the GLX_SGI_swap_control or
GLX_OML_sync_control extensions.
The value, percent, indicates the amount of time spent between the
completion of the two swaps. If the value is in the range [0,1], the
buffer swap occurred within the time period required to maintain a
constant frame rate. If the value is in the range (1,max], a constant
frame rate was not achieved. The value indicates the number of frames
required to draw.
This definition of "percent" differs slightly from
WGL_I3D_swap_frame_usage. In WGL_I3D_swap_frame_usage, the measurement
is taken from the completion of one swap to the issuance of the next.
This representation may not be as useful as measuring between
completions, as a significant amount of time may pass between the
issuance of a swap and the swap actually occurring.
There is also a mechanism to determine whether a frame swap was
missed.
New Procedures and Functions
int glXGetFrameUsageMESA(Display *dpy,
GLXDrawable drawable,
float *usage)
int glXBeginFrameTrackingMESA(Display *dpy,
GLXDrawable drawable)
int glXEndFrameTrackingMESA(Display *dpy,
GLXDrawable drawable)
int glXQueryFrameTrackingMESA(Display *dpy,
GLXDrawable drawable,
int64_t *swapCount,
int64_t *missedFrames,
float *lastMissedUsage)
New Tokens
None
Additions to Chapter 2 of the 1.4 GL Specification (OpenGL Operation)
None
Additions to Chapter 3 of the 1.4 GL Specification (Rasterization)
None
Additions to Chapter 4 of the 1.4 GL Specification (Per-Fragment Operations
and the Framebuffer)
None
Additions to Chapter 5 of the 1.4 GL Specification (Special Functions)
None
Additions to Chapter 6 of the 1.4 GL Specification (State and State Requests)
None
Additions to the GLX 1.3 Specification
The frame usage is measured as the percentage of the swap period elapsed
between two buffer-swap operations being committed. In unextended GLX the
swap period is the vertical refresh time. If SGI_swap_control or
MESA_swap_control are supported, the swap period is the vertical refresh
time multiplied by the swap interval (or one if the swap interval is set
to zero).
If OML_sync_control is supported, the swap period is the vertical
refresh time multiplied by the divisor parameter to
glXSwapBuffersMscOML. The frame usage in this case is less than 1.0 if
the swap is committed before target_msc, and is greater than or equal to
1.0 otherwise. The actual usage value is based on the divisor and is
never less than 0.0.
int glXBeginFrameTrackingMESA(Display *dpy,
GLXDrawable drawable,
float *usage)
glXGetFrameUsageMESA returns a floating-point value in <usage>
that represents the current swap usage, as defined above.
Missed frame swaps can be tracked by calling the following function:
int glXBeginFrameTrackingMESA(Display *dpy,
GLXDrawable drawable)
glXBeginFrameTrackingMESA resets a "missed frame" count and
synchronizes with the next frame vertical sync before it returns.
If a swap is missed based in the rate control specified by the
<interval> set by glXSwapIntervalSGI or the default swap of once
per frame, the missed frame count is incremented.
The current missed frame count and total number of swaps since
the last call to glXBeginFrameTrackingMESA can be obtained by
calling the following function:
int glXQueryFrameTrackingMESA(Display *dpy,
GLXDrawable drawable,
int64_t *swapCount,
int64_t *missedFrames,
float *lastMissedUsage)
The location pointed to by <swapCount> will be updated with the
number of swaps that have been committed. This value may not match the
number of swaps that have been requested since swaps may be
queued by the implementation. This function can be called at any
time and does not synchronize to vertical blank.
The location pointed to by <missedFrames> will contain the number
swaps that missed the specified frame. The frame usage for the
last missed frame is returned in the location pointed to by
<lastMissedUsage>.
Frame tracking is disabled by calling the function
int glXEndFrameTrackingMESA(Display *dpy,
GLXDrawable drawable)
This function will not return until all swaps have occurred. The
application can call glXQueryFrameTrackingMESA for a final swap and
missed frame count.
If these functions are successful, zero is returned. If the context
associated with dpy and drawable is not a direct context,
GLX_BAD_CONTEXT is returned.
Errors
If the function succeeds, zero is returned. If the function
fails, one of the following error codes is returned:
GLX_BAD_CONTEXT The current rendering context is not a direct
context.
GLX Protocol
None. This extension only extends to direct rendering contexts.
New State
None
New Implementation Dependent State
None
Revision History
1.1, 5/1/03 Added contact information.
1.0, 3/17/03 Initial version based on WGL_I3D_swap_frame_usage.
@@ -0,0 +1,804 @@
Name
MESA_texture_array
Name Strings
GL_MESA_texture_array
Contact
Ian Romanick, IBM (idr 'at' us.ibm.com)
IP Status
No known IP issues.
Status
DEPRECATED - Support removed in Mesa 10.1.
Version
Number
TBD
Dependencies
OpenGL 1.2 or GL_EXT_texture3D is required.
Support for ARB_fragment_program is assumed, but not required.
Support for ARB_fragment_program_shadow is assumed, but not required.
Support for EXT_framebuffer_object is assumed, but not required.
Written based on the wording of the OpenGL 2.0 specification and
ARB_fragment_program_shadow but not dependent on them.
Overview
There are a number of circumstances where an application may wish to
blend two textures out of a larger set of textures. Moreover, in some
cases the selected textures may vary on a per-fragment basis within
a polygon. Several examples include:
1. High dynamic range textures. The application stores several
different "exposures" of an image as different textures. On a
per-fragment basis, the application selects which exposures are
used.
2. A terrain engine where the altitude of a point determines the
texture applied to it. If the transition is from beach sand to
grass to rocks to snow, the application will store each texture
in a different texture map, and dynamically select which two
textures to blend at run-time.
3. Storing short video clips in textures. Each depth slice is a
single frame of video.
Several solutions to this problem have been proposed, but they either
involve using a separate texture unit for each texture map or using 3D
textures without mipmaps. Both of these options have major drawbacks.
This extension provides a third alternative that eliminates the major
drawbacks of both previous methods. A new texture target,
TEXTURE_2D_ARRAY, is added that functions identically to TEXTURE_3D in
all aspects except the sizes of the non-base level images. In
traditional 3D texturing, the size of the N+1 LOD is half the size
of the N LOD in all three dimensions. For the TEXTURE_2D_ARRAY target,
the height and width of the N+1 LOD is halved, but the depth is the
same for all levels of detail. The texture then becomes an array of
2D textures. The per-fragment texel is selected by the R texture
coordinate.
References:
https://www.opengl.org/discussion_boards/cgi_directory/ultimatebb.cgi?ubb=get_topic;f=3;t=011557
https://www.opengl.org/discussion_boards/cgi_directory/ultimatebb.cgi?ubb=get_topic;f=3;t=000516
https://www.opengl.org/discussion_boards/cgi_directory/ultimatebb.cgi?ubb=get_topic;f=3;t=011903
http://www.delphi3d.net/articles/viewarticle.php?article=terraintex.htm
New Procedures and Functions
All functions come directly from EXT_texture_array.
void FramebufferTextureLayerEXT(enum target, enum attachment,
uint texture, int level, int layer);
New Tokens
All token names and values come directly from EXT_texture_array.
Accepted by the <cap> parameter of Enable, Disable, and IsEnabled, by
the <pname> parameter of GetBooleanv, GetIntegerv, GetFloatv, and
GetDoublev, and by the <target> parameter of TexImage3D, GetTexImage,
GetTexLevelParameteriv, GetTexLevelParameterfv, GetTexParameteriv, and
GetTexParameterfv:
TEXTURE_1D_ARRAY_EXT 0x8C18
TEXTURE_2D_ARRAY_EXT 0x8C1A
Accepted by the <target> parameter of TexImage2D, TexSubImage2D,
CopyTexImage2D, CopyTexSubImage2D, CompressedTexImage2D,
CompressedTexSubImage2D, GetTexLevelParameteriv, and
GetTexLevelParameterfv:
TEXTURE_1D_ARRAY_EXT
PROXY_TEXTURE_1D_ARRAY_EXT 0x8C19
Accepted by the <target> parameter of TexImage3D, TexSubImage3D,
CopyTexSubImage3D, CompressedTexImage3D, CompressedTexSubImage3D,
GetTexLevelParameteriv, and GetTexLevelParameterfv:
TEXTURE_2D_ARRAY_EXT
PROXY_TEXTURE_2D_ARRAY_EXT 0x8C1B
Accepted by the <pname> parameter of GetBooleanv, GetIntegerv,
GetFloatv, and GetDoublev
TEXTURE_BINDING_1D_ARRAY_EXT 0x8C1C
TEXTURE_BINDING_2D_ARRAY_EXT 0x8C1D
MAX_ARRAY_TEXTURE_LAYERS_EXT 0x88FF
Accepted by the <param> parameter of TexParameterf, TexParameteri,
TexParameterfv, and TexParameteriv when the <pname> parameter is
TEXTURE_COMPARE_MODE_ARB:
COMPARE_REF_DEPTH_TO_TEXTURE_EXT 0x884E
(Note: COMPARE_REF_DEPTH_TO_TEXTURE_EXT is simply an alias for the
existing COMPARE_R_TO_TEXTURE token in OpenGL 2.0; the alternate name
reflects the fact that the R coordinate is not always used.)
Accepted by the <internalformat> parameter of TexImage3D and
CompressedTexImage3D, and by the <format> parameter of
CompressedTexSubImage3D:
COMPRESSED_RGB_S3TC_DXT1_EXT
COMPRESSED_RGBA_S3TC_DXT1_EXT
COMPRESSED_RGBA_S3TC_DXT3_EXT
COMPRESSED_RGBA_S3TC_DXT5_EXT
Accepted by the <pname> parameter of
GetFramebufferAttachmentParameterivEXT:
FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER_EXT 0x8CD4
(Note: FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER is simply an alias for the
FRAMEBUFFER_ATTACHMENT_TEXTURE_3D_ZOFFSET_EXT token provided in
EXT_framebuffer_object. This extension generalizes the notion of
"<zoffset>" to include layers of an array texture.)
Additions to Chapter 2 of the OpenGL 2.0 Specification (OpenGL Operation)
None
Additions to Chapter 3 of the OpenGL 2.0 Specification (Rasterization)
-- Section 3.8.1 "Texture Image Specification"
Change the first paragraph (page 150) to say (spec changes identical to
EXT_texture_array):
"The command
void TexImage3D(enum target, int level, int internalformat,
sizei width, sizei height, sizei depth, int border,
enum format, enum type, void *data);
is used to specify a three-dimensional texture image. target must be one
one of TEXTURE_3D for a three-dimensional texture or
TEXTURE_2D_ARRAY_EXT for an two-dimensional array texture.
Additionally, target may be either PROXY_TEXTURE_3D for a
three-dimensional proxy texture, or PROXY_TEXTURE_2D_ARRAY_EXT for a
two-dimensional proxy array texture."
Change the fourth paragraph on page 151 to say (spec changes identical
to EXT_texture_array):
"Textures with a base internal format of DEPTH_COMPONENT are supported
by texture image specification commands only if target is TEXTURE_1D,
TEXTURE_2D, TEXTURE_1D_ARRAY_EXT, TEXTURE_2D_ARRAY_EXT,
PROXY_TEXTURE_1D, PROXY_TEXTURE_2D, PROXY_TEXTURE_1D_ARRAY_EXT, or
PROXY_TEXTURE_2D_ARRAY_EXT. Using this format in conjunction with any
other target will result in an INVALID_OPERATION error."
Change the fourth paragraph on page 156 to say (spec changes identical
to EXT_texture_array):
"The command
void TexImage2D(enum target, int level,
int internalformat, sizei width, sizei height,
int border, enum format, enum type, void *data);
is used to specify a two-dimensional texture image. target must be one
of TEXTURE_2D for a two-dimensional texture, TEXTURE_1D_ARRAY_EXT for a
one-dimensional array texture, or one of TEXTURE_CUBE_MAP_POSITIVE_X,
TEXTURE_CUBE_MAP_NEGATIVE_X, TEXTURE_CUBE_MAP_POSITIVE_Y,
TEXTURE_CUBE_MAP_NEGATIVE_Y, TEXTURE_CUBE_MAP_POSITIVE_Z, or
TEXTURE_CUBE_MAP_NEGATIVE_Z for a cube map texture. Additionally,
target may be either PROXY_TEXTURE_2D for a two-dimensional proxy
texture, PROXY_TEXTURE_1D_ARRAY_EXT for a one-dimensional proxy array
texture, or PROXY TEXTURE_CUBE_MAP for a cube map proxy texture in the
special case discussed in section 3.8.11. The other parameters match
the corresponding parameters of TexImage3D.
For the purposes of decoding the texture image, TexImage2D is
equivalent to calling TexImage3D with corresponding arguments and depth
of 1, except that
* The border depth, d_b, is zero, and the depth of the image is
always 1 regardless of the value of border.
* The border height, h_b, is zero if <target> is
TEXTURE_1D_ARRAY_EXT, and <border> otherwise.
* Convolution will be performed on the image (possibly changing its
width and height) if SEPARABLE 2D or CONVOLUTION 2D is enabled.
* UNPACK SKIP IMAGES is ignored."
-- Section 3.8.2 "Alternate Texture Image Specification Commands"
Change the second paragraph (page 159) (spec changes identical
to EXT_texture_array):
"The command
void CopyTexImage2D(enum target, int level,
enum internalformat, int x, int y, sizei width,
sizei height, int border);
defines a two-dimensional texture image in exactly the manner of
TexImage2D, except that the image data are taken from the framebuffer
rather than from client memory. Currently, target must be one of
TEXTURE_2D, TEXTURE_1D_ARRAY_EXT, TEXTURE_CUBE_MAP_POSITIVE_X,
TEXTURE_CUBE_MAP_NEGATIVE_X, TEXTURE_CUBE MAP_POSITIVE_Y,
TEXTURE_CUBE_MAP_NEGATIVE_Y, TEXTURE_CUBE_MAP_POSITIVE_Z, or
TEXTURE_CUBE_MAP_NEGATIVE_Z.
Change the last paragraph on page 160 to say (spec changes identical
to EXT_texture_array):
"Currently the target arguments of TexSubImage1D and CopyTexSubImage1D
must be TEXTURE_1D, the target arguments of TexSubImage2D and
CopyTexSubImage2D must be one of TEXTURE_2D, TEXTURE_1D_ARRAY_EXT,
TEXTURE_CUBE_MAP_POSITIVE_X, TEXTURE_CUBE_MAP_NEGATIVE_X,
TEXTURE_CUBE_MAP_POSITIVE_Y, TEXTURE_CUBE_MAP_NEGATIVE_Y,
TEXTURE_CUBE_MAP_POSITIVE_Z, or TEXTURE_CUBE_MAP_NEGATIVE_Z, and the
target arguments of TexSubImage3D and CopyTexSubImage3D must be
TEXTURE_3D or TEXTURE_2D_ARRAY_EXT. ..."
-- Section 3.8.4 "Texture Parameters"
Change the first paragraph (page 166) to say:
"Various parameters control how the texel array is treated when
specified or changed, and when applied to a fragment. Each parameter is
set by calling
void TexParameter{if}(enum target, enum pname, T param);
void TexParameter{if}v(enum target, enum pname, T params);
target is the target, either TEXTURE_1D, TEXTURE_2D, TEXTURE_3D,
TEXTURE_CUBE_MAP, TEXTURE_1D_ARRAY_EXT, or TEXTURE_2D_ARRAY_EXT."
-- Section 3.8.8 "Texture Minification" in the section "Scale Factor and Level of Detail"
Change the first paragraph (page 172) to say:
"Let s(x,y) be the function that associates an s texture coordinate
with each set of window coordinates (x,y) that lie within a primitive;
define t(x,y) and r(x,y) analogously. Let u(x,y) = w_t * s(x,y),
v(x,y) = h_t * t(x,y), and w(x,y) = d_t * r(x,y), where w_t, h_t,
and d_t are as defined by equations 3.15, 3.16, and 3.17 with
w_s, h_s, and d_s equal to the width, height, and depth of the
image array whose level is level_base. For a one-dimensional
texture or a one-dimensional array texture, define v(x,y) = 0 and
w(x,y) = 0; for a two-dimensional texture or a two-dimensional array
texture, define w(x,y) = 0..."
-- Section 3.8.8 "Texture Minification" in the section "Mipmapping"
Change the third paragraph (page 174) to say:
"For a two-dimensional texture, two-dimensional array texture, or
cube map texture,"
Change the fourth paragraph (page 174) to say:
"And for a one-dimensional texture or a one-dimensional array texture,"
After the first paragraph (page 175) add:
"For one-dimensional array textures, h_b and d_b are treated as 1,
regardless of the actual values, when performing mipmap calculations.
For two-dimensional array textures, d_b is always treated as one,
regardless of the actual value, when performing mipmap calculations."
-- Section 3.8.8 "Automatic Mipmap Generation" in the section "Mipmapping"
Change the third paragraph (page 176) to say (spec changes identical
to EXT_texture_array):
"The contents of the derived arrays are computed by repeated, filtered
reduction of the level_base array. For one- and two-dimensional array
textures, each layer is filtered independently. ..."
-- Section 3.8.8 "Manual Mipmap Generation" in the section "Mipmapping"
Change first paragraph to say (spec changes identical to
EXT_texture_array):
"Mipmaps can be generated manually with the command
void GenerateMipmapEXT(enum target);
where <target> is one of TEXTURE_1D, TEXTURE_2D, TEXTURE_CUBE_MAP,
TEXTURE_3D, TEXTURE_1D_ARRAY, or TEXTURE_2D_ARRAY. Mipmap generation
affects the texture image attached to <target>. ..."
-- Section 3.8.10 "Texture Completeness"
Change the second paragraph (page 177) to say (spec changes identical
to EXT_texture_array):
"For one-, two-, or three-dimensional textures and one- or
two-dimensional array textures, a texture is complete if the following
conditions all hold true:"
-- Section 3.8.11 "Texture State and Proxy State"
Change the second and third paragraphs (page 179) to say (spec changes
identical to EXT_texture_array):
"In addition to image arrays for one-, two-, and three-dimensional
textures, one- and two-dimensional array textures, and the six image
arrays for the cube map texture, partially instantiated image arrays
are maintained for one-, two-, and three-dimensional textures and one-
and two-dimensional array textures. Additionally, a single proxy image
array is maintained for the cube map texture. Each proxy image array
includes width, height, depth, border width, and internal format state
values, as well as state for the red, green, blue, alpha, luminance,
and intensity component resolutions. Proxy image arrays do not include
image data, nor do they include texture properties. When TexImage3D is
executed with target specified as PROXY_TEXTURE_3D, the
three-dimensional proxy state values of the specified level-of-detail
are recomputed and updated. If the image array would not be supported
by TexImage3D called with target set to TEXTURE 3D, no error is
generated, but the proxy width, height, depth, border width, and
component resolutions are set to zero. If the image array would be
supported by such a call to TexImage3D, the proxy state values are set
exactly as though the actual image array were being specified. No pixel
data are transferred or processed in either case.
Proxy arrays for one- and two-dimensional textures and one- and
two-dimensional array textures are operated on in the same way when
TexImage1D is executed with target specified as PROXY_TEXTURE_1D,
TexImage2D is executed with target specified as PROXY_TEXTURE_2D or
PROXY_TEXTURE_1D_ARRAY_EXT, or TexImage3D is executed with target
specified as PROXY_TETXURE_2D_ARRAY_EXT."
-- Section 3.8.12 "Texture Objects"
Change section (page 180) to say (spec changes identical to
EXT_texture_array):
"In addition to the default textures TEXTURE_1D, TEXTURE_2D,
TEXTURE_3D, TEXTURE_CUBE_MAP, TEXTURE_1D_ARRAY_EXT, and TEXTURE_2D_EXT,
named one-, two-, and three-dimensional, cube map, and one- and
two-dimensional array texture objects can be created and operated upon.
The name space for texture objects is the unsigned integers, with zero
reserved by the GL.
A texture object is created by binding an unused name to TEXTURE_1D,
TEXTURE_2D, TEXTURE_3D, TEXTURE_CUBE_MAP, TEXTURE_1D_ARRAY_EXT, or
TEXTURE_2D_ARRAY_EXT. The binding is effected by calling
void BindTexture(enum target, uint texture);
with <target> set to the desired texture target and <texture> set to
the unused name. The resulting texture object is a new state vector,
comprising all the state values listed in section 3.8.11, set to the
same initial values. If the new texture object is bound to TEXTURE_1D,
TEXTURE_2D, TEXTURE_3D, TEXTURE_CUBE_MAP, TEXTURE_1D_ARRAY_EXT, or
TEXTURE_2D_ARRAY_EXT, it is and remains a one-, two-,
three-dimensional, cube map, one- or two-dimensional array texture
respectively until it is deleted.
BindTexture may also be used to bind an existing texture object to
either TEXTURE_1D, TEXTURE_2D, TEXTURE_3D, TEXTURE_CUBE_MAP,
TEXTURE_1D_ARRAY_EXT, or TEXTURE_2D_ARRAY_EXT. The error
INVALID_OPERATION is generated if an attempt is made to bind a texture
object of different dimensionality than the specified target. If the
bind is successful no change is made to the state of the bound texture
object, and any previous binding to target is broken.
While a texture object is bound, GL operations on the target to which
it is bound affect the bound object, and queries of the target to which
it is bound return state from the bound object. If texture mapping of
the dimensionality of the target to which a texture object is bound is
enabled, the state of the bound texture object directs the texturing
operation.
In the initial state, TEXTURE_1D, TEXTURE_2D, TEXTURE_3D,
TEXTURE_CUBE_MAP, TEXTURE_1D_ARRAY_EXT, and TEXTURE_2D_ARRAY_EXT have
one-, two-, three-dimensional, cube map, and one- and two-dimensional
array texture state vectors respectively associated with them. In order
that access to these initial textures not be lost, they are treated as
texture objects all of whose names are 0. The initial one-, two-,
three-dimensional, cube map, one- and two-dimensional array textures
are therefore operated upon, queried, and applied as TEXTURE_1D,
TEXTURE_2D, TEXTURE_3D, TEXTURE_CUBE_MAP, TEXTURE_1D_ARRAY_EXT, and
TEXTURE_2D_ARRAY_EXT respectively while 0 is bound to the corresponding
targets.
Change second paragraph on page 181 to say (spec changes identical to
EXT_texture_array):
"... If a texture that is currently bound to one of the targets
TEXTURE_1D, TEXTURE_2D, TEXTURE_3D, TEXTURE_CUBE_MAP,
TEXTURE_1D_ARRAY_EXT, or TEXTURE_2D_ARRAY_EXT is deleted, it is as
though BindTexture had been executed with the same target and texture
zero. ..."
Change second paragraph on page 182 to say (spec changes identical to
EXT_texture_array):
"The texture object name space, including the initial one-, two-, and
three dimensional, cube map, and one- and two-dimensional array texture
objects, is shared among all texture units. ..."
-- Section 3.8.14 "Depth Texture Comparison Modes" in "Texture Comparison Modes"
Change second through fourth paragraphs (page 188) to say:
"Let D_t be the depth texture value, in the range [0, 1]. For
texture lookups from one- and two-dimensional, rectangle, and
one-dimensional array targets, let R be the interpolated <r>
texture coordinate, clamped to the range [0, 1]. For texture lookups
from two-dimensional array texture targets, let R be the interpolated
<q> texture coordinate, clamped to the range [0, 1]. Then the
effective texture value L_t, I_t, or A_t is computed as follows:
If the value of TEXTURE_COMPARE_MODE is NONE, then
r = Dt
If the value of TEXTURE_COMPARE_MODE is
COMPARE_REF_DEPTH_TO_TEXTURE_EXT), then r depends on the texture
comparison function as shown in table 3.27."
-- Section 3.8.15 "Texture Application"
Change the first paragraph (page 189) to say:
"Texturing is enabled or disabled using the generic Enable and Disable
commands, respectively, with the symbolic constants TEXTURE_1D,
TEXTURE_2D, TEXTURE_3D, TEXTURE_CUBE_MAP, TEXTURE_1D_ARRAY_EXT, or
TEXTURE_2D_ARRAY_EXT to enable one-, two-, three-dimensional, cube
map, one-dimensional array, or two-dimensional array texture,
respectively. If both two- and one-dimensional textures are enabled,
the two-dimensional texture is used. If the three-dimensional and
either of the two- or one-dimensional textures is enabled, the
three-dimensional texture is used. If the cube map texture and any of
the three-, two-, or one-dimensional textures is enabled, then cube map
texturing is used. If one-dimensional array texture is enabled and any
of cube map, three-, two-, or one-dimensional textures is enabled,
one-dimensional array texturing is used. If two-dimensional array
texture is enabled and any of cube map, three-, two-, one-dimensional
textures or one-dimensional array texture is enabled, two-dimensional
array texturing is used..."
-- Section 3.11.2 of ARB_fragment_program (Fragment Program Grammar and Restrictions):
(mostly add to existing grammar rules)
<optionName> ::= "MESA_texture_array"
<texTarget> ::= "1D"
| "2D"
| "3D"
| "CUBE"
| "RECT"
| <arrayTarget> (if program option is present)
| <shadowTarget> (if program option is present)
<arrayTarget> ::= "ARRAY1D"
| "ARRAY2D"
<shadowTarget> ::= "SHADOW1D"
| "SHADOW2D"
| "SHADOWRECT"
| <shadowArrayTarget> (if program option is present)
<shadowArrayTarget> ::= "SHADOWARRAY1D"
| "SHADOWARRAY2D"
-- Add Section 3.11.4.5.4 "Texture Stack Option"
"If a fragment program specifies the "MESA_texture_array" program
option, the <texTarget> rule is modified to add the texture targets
ARRAY1D and ARRAY2D (See Section 3.11.2)."
-- Section 3.11.6 "Fragment Program Texture Instruction Set"
(replace 1st and 2nd paragraphs with the following paragraphs)
"The first three texture instructions described below specify the
mapping of 4-tuple input vectors to 4-tuple output vectors.
The sampling of the texture works as described in section 3.8,
except that texture environments and texture functions are not
applicable, and the texture enables hierarchy is replaced by explicit
references to the desired texture target (i.e., 1D, 2D, 3D, cube map,
rectangle, ARRAY1D, ARRAY2D). These texture instructions specify
how the 4-tuple is mapped into the coordinates used for sampling. The
following function is used to describe the texture sampling in the
descriptions below:
vec4 TextureSample(vec4 coord, float lodBias, int texImageUnit,
enum texTarget);
Note that not all four components of the texture coordinates <coord>
are used by all texture targets. Component usage for each <texTarget>
is defined in table X.
coordinates used
texTarget Texture Type s t r layer shadow
---------------- --------------------- ----- ----- ------
1D TEXTURE_1D x - - - -
2D TEXTURE_2D x y - - -
3D TEXTURE_3D x y z - -
CUBE TEXTURE_CUBE_MAP x y z - -
RECT TEXTURE_RECTANGLE_ARB x y - - -
ARRAY1D TEXTURE_1D_ARRAY_EXT x - - y -
ARRAY2D TEXTURE_2D_ARRAY_EXT x y - z -
SHADOW1D TEXTURE_1D x - - - z
SHADOW2D TEXTURE_2D x y - - z
SHADOWRECT TEXTURE_RECTANGLE_ARB x y - - z
SHADOWARRAY1D TEXTURE_1D_ARRAY_EXT x - - y z
SHADOWARRAY2D TEXTURE_2D_ARRAY_EXT x y - z w
Table X: Texture types accessed for each of the <texTarget>, and
coordinate mappings. The "coordinates used" column indicate the
input values used for each coordinate of the texture lookup, the
layer selector for array textures, and the reference value for
texture comparisons."
-- Section 3.11.6.2 "TXP: Project coordinate and map to color"
Add to the end of the section:
"A program will fail to load if the TXP instruction is used in
conjunction with the SHADOWARRAY2D target."
Additions to Chapter 4 of the OpenGL 2.0 Specification (Per-Fragment Operations)
-- Section 4.4.2.3 "Attaching Texture Images to a Framebuffer"
Add to the end of the section (spec changes identical to
EXT_texture_array):
"The command
void FramebufferTextureLayerEXT(enum target, enum attachment,
uint texture, int level, int layer);
operates identically to FramebufferTexture3DEXT, except that it
attaches a single layer of a three-dimensional texture or a one- or
two-dimensional array texture. <layer> is an integer indicating the
layer number, and is treated identically to the <zoffset> parameter in
FramebufferTexture3DEXT. The error INVALID_VALUE is generated if
<layer> is negative. The error INVALID_OPERATION is generated if
<texture> is non-zero and is not the name of a three dimensional
texture or one- or two-dimensional array texture. Unlike
FramebufferTexture3D, no <textarget> parameter is accepted.
If <texture> is non-zero and the command does not result in an error,
the framebuffer attachment state corresponding to <attachment> is
updated as in the other FramebufferTexture commands, except that
FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER_EXT is set to <layer>."
-- Section 4.4.4.1 "Framebuffer Attachment Completeness"
Add to the end of the list of completeness rules (spec changes
identical to EXT_texture_array):
"* If FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE_EXT is TEXTURE and
FRAMEBUFFER_ATTACHMENT_OBJECT_NAME_EXT names a one- or
two-dimensional array texture, then
FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER_EXT must be smaller than the
number of layers in the texture."
Additions to Chapter 5 of the OpenGL 2.0 Specification (Special Functions)
-- Section 5.4 "Display Lists"
Change the first paragraph on page 242 to say (spec changes
identical to EXT_texture_array):
"TexImage3D, TexImage2D, TexImage1D, Histogram, and ColorTable are
executed immediately when called with the corresponding proxy arguments
PROXY_TEXTURE_3D or PROXY_TEXTURE_2D_ARRAY_EXT; PROXY_TEXTURE_2D,
PROXY_TEXTURE_CUBE_MAP, or PROXY_TEXTURE_1D_ARRAY_EXT;
PROXY_TEXTURE_1D; PROXY_HISTOGRAM; and PROXY_COLOR_TABLE,
PROXY_POST_CONVOLUTION_COLOR_TABLE, or
PROXY_POST_COLOR_MATRIX_COLOR_TABLE."
Additions to Chapter 6 of the OpenGL 2.0 Specification (State and State Requests)
-- Section 6.1.3 "Enumerated Queries"
Add after the line beginning "If the value of
FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE_EXT is TEXTURE" (spec changes
identical to EXT_texture_array):
"If <pname> is FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER_EXT and the
texture object named FRAMEBUFFER_ATTACHMENT_OBJECT_NAME_EXT is a
three-dimensional texture or a one- or two-dimensional array texture,
then <params> will contain the number of texture layer attached to the
attachment point. Otherwise, <params> will contain the value zero."
-- Section 6.1.4 "Texture Queries"
Change the first three paragraphs (page 248) to say (spec changes
identical to EXT_texture_array):
"The command
void GetTexImage(enum tex, int lod, enum format,
enum type, void *img);
is used to obtain texture images. It is somewhat different from the
other get commands; tex is a symbolic value indicating which texture
(or texture face in the case of a cube map texture target name) is to
be obtained. TEXTURE_1D, TEXTURE_2D, TEXTURE_3D, TEXTURE_1D_ARRAY_EXT,
and TEXTURE_2D_ARRAY_EXT indicate a one-, two-, or three-dimensional
texture, or one- or two-dimensional array texture, respectively.
TEXTURE_CUBE_MAP_POSITIVE_X, ...
GetTexImage obtains... from the first image to the last for
three-dimensional textures. One- and two-dimensional array textures
are treated as two- and three-dimensional images, respectively, where
the layers are treated as rows or images. These groups are then...
For three-dimensional and two-dimensional array textures, pixel storage
operations are applied as if the image were two-dimensional, except
that the additional pixel storage state values PACK_IMAGE_HEIGHT and
PACK_SKIP_IMAGES are applied. ..."
Additions to Appendix A of the OpenGL 2.0 Specification (Invariance)
None
Additions to the AGL/GLX/WGL Specifications
None
GLX Protocol
None
Dependencies on ARB_fragment_program
If ARB_fragment_program is not supported, the changes to section 3.11
should be ignored.
Dependencies on EXT_framebuffer_object
If EXT_framebuffer_object is not supported, the changes to section
3.8.8 ("Manual Mipmap Generation"), 4.4.2.3, and 6.1.3 should be ignored.
Dependencies on EXT_texture_compression_s3tc and NV_texture_compression_vtc
(Identical dependency as EXT_texture_array.)
S3TC texture compression is supported for two-dimensional array textures.
When <target> is TEXTURE_2D_ARRAY_EXT, each layer is stored independently
as a compressed two-dimensional textures. When specifying or querying
compressed images using one of the S3TC formats, the images are provided
and/or returned as a series of two-dimensional textures stored
consecutively in memory, with the layer closest to zero specified first.
For array textures, images are not arranged in 4x4x4 or 4x4x2 blocks as in
the three-dimensional compression format provided in the
EXT_texture_compression_vtc extension. Pixel store parameters, including
those specific to three-dimensional images, are ignored when compressed
image data are provided or returned, as in the
EXT_texture_compression_s3tc extension.
S3TC compression is not supported for one-dimensional texture targets in
EXT_texture_compression_s3tc, and is not supported for one-dimensional
array textures in this extension. If compressed one-dimensional arrays
are needed, use a two-dimensional texture with a height of one.
This extension allows the use of the four S3TC internal format types in
TexImage3D, CompressedTexImage3D, and CompressedTexSubImage3D calls.
Errors
None
New State
(add to table 6.15, p. 276)
Initial
Get Value Type Get Command Value Description Sec. Attribute
---------------------------- ----- ----------- ----- -------------------- ------ ---------
TEXTURE_BINDING_1D_ARRAY_EXT 2*xZ+ GetIntegerv 0 texture object bound 3.8.12 texture
to TEXTURE_1D_ARRAY
TEXTURE_BINDING_2D_ARRAY_EXT 2*xZ+ GetIntegerv 0 texture object bound 3.8.12 texture
to TEXTURE_2D_ARRAY
New Implementation Dependent State
(add to Table 6.32, p. 293)
Minimum
Get Value Type Get Command Value Description Sec. Attribute
---------------------------- ---- ----------- ------- ------------------ ----- ---------
MAX_TEXTURE_ARRAY_LAYERS_EXT Z+ GetIntegerv 64 maximum number of 3.8.1 -
layers for texture
arrays
Issues
(1) Is "texture stack" a good name for this functionality?
NO. The name is changed to "array texture" to match the
nomenclature used by GL_EXT_texture_array.
(2) Should the R texture coordinate be treated as normalized or
un-normalized? If it were un-normalized, floor(R) could be thought
of as a direct index into the array texture. This may be more
convenient for applications.
RESOLVED. All texture coordinates are normalized. The issue of
un-normalized texture coordinates has been discussed in the ARB
before and should be left for a layered extension.
RE-RESOLVED. The R coordinate is un-normalized. Accessing an array
using [0, layers-1] coordinates is much more natural.
(3) How does LOD selection work for stacked textures?
RESOLVED. For 2D array textures the R coordinate is ignored, and
the LOD selection equations for 2D textures are used. For 1D
array textures the T coordinate is ignored, and the LOD selection
equations for 1D textures are used. The expected usage is in a
fragment program with an explicit LOD selection.
(4) What is the maximum size of a 2D array texture? Is it the same
as for a 3D texture, or should a new query be added? How about for 1D
array textures?
RESOLVED. A new query is added.
(5) How are array textures exposed in GLSL?
RESOLVED. Use GL_EXT_texture_array.
(6) Should a 1D array texture also be exposed?
RESOLVED. For orthogonality, yes.
(7) How are stacked textures attached to framebuffer objects?
RESOLVED. Layers of both one- and two-dimensional array textures
are attached using FreambufferTextureLayerEXT. Once attached, the
array texture layer behaves exactly as either a one- or
two-dimensional texture.
(8) How is this extension related to GL_EXT_texture_array?
This extension adapats GL_MESAX_texture_stack to the notation,
indexing, and FBO access of GL_EXT_texture_array. This extension
replaces the GLSL support of GL_EXT_texture_array with
GL_ARB_fragment_program support.
Assembly program support is also provided by GL_NV_gpu_program4.
GL_NV_gpu_program4 also adds support for other features that are
specific to Nvidia hardware, while this extension adds only support
for array textures.
Much of text of this extension that has changed since
GL_MESAX_texture_stack comes directly from either
GL_EXT_texture_array or GL_NV_gpu_program4.
Revision History
||2005/11/15||0.1||idr||Initial draft MESAX version.||
||2005/12/07||0.2||idr||Added framebuffer object interactions.||
||2005/12/12||0.3||idr||Updated fragment program interactions.||
||2007/05/16||0.4||idr||Converted to MESA_texture_array. Brought in line with EXT_texture_array and NV_gpu_program4.||
+359
View File
@@ -0,0 +1,359 @@
Name
MESA_trace
Name Strings
GL_MESA_trace
Contact
Bernd Kreimeier, Loki Entertainment, bk 'at' lokigames.com
Brian Paul, VA Linux Systems, Inc., brianp 'at' valinux.com
Status
Obsolete.
Version
Number
none yet
Dependencies
OpenGL 1.2 is required.
The extension is written against the OpenGL 1.2 Specification
Overview
Provides the application with means to enable and disable logging
of GL calls including parameters as readable text. The verbosity
of the generated log can be controlled. The resulting logs are
valid (but possibly incomplete) C code and can be compiled and
linked for standalone test programs. The set of calls and the
amount of static data that is logged can be controlled at runtime.
The application can add comments and enable or disable tracing of GL
operations at any time. The data flow from the application to GL
and back is unaffected except for timing.
Application-side implementation of these features raises namespace
and linkage issues. In the driver dispatch table a simple
"chain of responsibility" pattern (aka "composable piepline")
can be added.
IP Status
The extension spec is in the public domain. The current implementation
in Mesa is covered by Mesa's XFree86-style copyright by the authors above.
This extension is partially inspired by the Quake2 QGL wrapper.
Issues
(1) Is this Extension obsolete because it can
be implemented as a wrapper DLL?
RESOLVED: No. While certain operating systems (Win32) provide linkers
that facilitate this kind of solution, other operating systems
(Linux) do not support hierarchical linking, so a wrapper solution
would result in symbol collisions.
Further, IHV's might have builtin support for tracing GL execution
that enjoys privileged access, or that they do not wish to separate
the tracing code from their driver code base.
(2) Should the Trace API explicitly support the notion of "frames?
This would require hooking into glXSwapBuffers calls as well.
RESOLVED: No. The application can use NewTraceMESA/EndTraceMESA
and TraceComment along with external parsing tools to split the
trace into frames, in whatever way considered adequate.
(2a) Should GLX calls be traced?
PBuffers and other render-to-texture solutions demonstrate that
context level commands beyond SwapBuffers might have to be
traced. The GL DLL exports the entry points, so this would not
be out of the question.
(3) Should the specification mandate the actual output format?
RESOLVED: No. It is sufficient to guarantee that all data and commands
will be traced as requested by Enable/DisableTraceMESA, in the order
encountered. Whether the resulting trace is available as a readable
text file, binary metafile, compilable source code, much less which
indentation and formatting has been used, is up to the implementation.
For the same reason this specification does not enforce or prohibit
additional information added to the trace (statistics, profiling/timing,
warnings on possible error conditions).
(4) Should the comment strings associated with names and pointer (ranges)
be considered persistent state?
RESOLVED: No. The implementation is not forced to use this information
on subsequent occurrences of name/pointer, and is free to consider it
transient state.
(5) Should comment commands be prohibited between Begin/End?
RESOLVED: Yes, with the exception of TraceCommentMESA. TraceCommentMESA
is transient, the other commands might cause storage of persistent
data in the context. There is no need to have the ability mark names
or pointers between Begin and End.
New Procedures and Functions
void NewTraceMESA( bitfield mask, const ubyte * traceName )
void EndTraceMESA( void )
void EnableTraceMESA( bitfield mask )
void DisableTraceMESA( bitfield mask )
void TraceAssertAttribMESA( bitfield attribMask )
void TraceCommentMESA( const ubyte* comment )
void TraceTextureMESA( uint name, const ubyte* comment )
void TraceListMESA( uint name, const ubyte* comment )
void TracePointerMESA( void* pointer, const ubyte* comment )
void TracePointerRangeMESA( const void* first,
const void* last,
const ubyte* comment )
New Tokens
Accepted by the <mask> parameter of EnableTrace and DisableTrace:
TRACE_ALL_BITS_MESA 0xFFFF
TRACE_OPERATIONS_BIT_MESA 0x0001
TRACE_PRIMITIVES_BIT_MESA 0x0002
TRACE_ARRAYS_BIT_MESA 0x0004
TRACE_TEXTURES_BIT_MESA 0x0008
TRACE_PIXELS_BIT_MESA 0x0010
TRACE_ERRORS_BIT_MESA 0x0020
Accepted by the <pname> parameter of GetIntegerv, GetBooleanv,
GetFloatv, and GetDoublev:
TRACE_MASK_MESA 0x8755
Accepted by the <pname> parameter to GetString:
TRACE_NAME_MESA 0x8756
Additions to Chapter 2 of the OpenGL 1.2.1 Specification (OpenGL Operation)
None.
Additions to Chapter 3 of the OpenGL 1.2.1 Specification (OpenGL Operation)
None.
Additions to Chapter 4 of the OpenGL 1.2.1 Specification (OpenGL Operation)
None.
Additions to Chapter 5 of the OpenGL 1.2.1 Specification (Special Functions)
Add a new section:
5.7 Tracing
The tracing facility is used to record the execution of a GL program
to a human-readable log. The log appears as a sequence of GL commands
using C syntax. The primary intention of tracing is to aid in program
debugging.
A trace is started with the command
void NewTraceMESA( bitfield mask, const GLubyte * traceName )
<mask> may be any value accepted by PushAttrib and specifies a set of
attribute groups. The state values included in those attribute groups
is written to the trace as a sequence of GL commands.
<traceName> specifies a name or label for the trace. It is expected
that <traceName> will be interpreted as a filename in most implementations.
A trace is ended by calling the command
void EndTraceMESA( void )
It is illegal to call NewTraceMESA or EndTraceMESA between Begin and End.
The commands
void EnableTraceMESA( bitfield mask )
void DisableTraceMESA( bitfield mask )
enable or disable tracing of different classes of GL commands.
<mask> may be the union of any of TRACE_OPERATIONS_BIT_MESA,
TRACE_PRIMITIVES_BIT_MESA, TRACE_ARRAYS_BIT_MESA, TRACE_TEXTURES_BIT_MESA,
and TRACE_PIXELS_BIT_MESA. The special token TRACE_ALL_BITS_MESA
indicates all classes of commands are to be logged.
TRACE_OPERATIONS_BIT_MESA controls logging of all commands outside of
Begin/End, including Begin/End.
TRACE_PRIMITIVES_BIT_MESA controls logging of all commands inside of
Begin/End, including Begin/End.
TRACE_ARRAYS_BIT_MESA controls logging of VertexPointer, NormalPointer,
ColorPointer, IndexPointer, TexCoordPointer and EdgeFlagPointer commands.
TRACE_TEXTURES_BIT_MESA controls logging of texture data dereferenced by
TexImage1D, TexImage2D, TexImage3D, TexSubImage1D, TexSubImage2D, and
TexSubImage3D commands.
TRACE_PIXELS_BIT_MESA controls logging of image data dereferenced by
Bitmap and DrawPixels commands.
TRACE_ERRORS_BIT_MESA controls logging of all errors. If this bit is
set, GetError will be executed wherever applicable, and the result will
be added to the trace as a comment. The error returns are cached and
returned to the application on its GetError calls. If the user does not
wish the additional GetError calls to be performed, this bit should not
be set.
The command
void TraceCommentMESA( const ubyte* comment )
immediately adds the <comment> string to the trace output, surrounded
by C-style comment delimiters.
The commands
void TraceTextureMESA( uint name, const ubyte* comment )
void TraceListMESA( uint name, const ubyte* comment )
associates <comment> with the texture object or display list specified
by <name>. Logged commands which reference the named texture object or
display list will be annotated with <comment>. If IsTexture(name) or
IsList(name) fail (respectively) the command is quietly ignored.
The commands
void TracePointerMESA( void* pointer, const ubyte* comment )
void TracePointerRangeMESA( const void* first,
const void* last,
const ubyte* comment )
associate <comment> with the address specified by <pointer> or with
a range of addresses specified by <first> through <last>.
Any logged commands which reference <pointer> or an address between
<first> and <last> will be annotated with <comment>.
The command
void TraceAssertAttribMESA( bitfield attribMask )
will add GL state queries and assertion statements to the log to
confirm that the current state at the time TraceAssertAttrib is
executed matches the current state when the trace log is executed
in the future.
<attribMask> is any value accepted by PushAttrib and specifies
the groups of state variables which are to be asserted.
The commands NewTraceMESA, EndTraceMESA, EnableTraceMESA, DisableTraceMESA,
TraceAssertAttribMESA, TraceCommentMESA, TraceTextureMESA, TraceListMESA,
TracePointerMESA and TracePointerRangeMESA are not compiled into display lists.
Examples:
The command NewTraceMESA(DEPTH_BUFFER_BIT, "log") will query the state
variables DEPTH_TEST, DEPTH_FUNC, DEPTH_WRITEMASK, and DEPTH_CLEAR_VALUE
to get the values <test>, <func>, <mask>, and <clear> respectively.
Statements equivalent to the following will then be logged:
glEnable(GL_DEPTH_TEST); (if <test> is true)
glDisable(GL_DEPTH_TEST); (if <test> is false)
glDepthFunc(<func>);
glDepthMask(<mask>);
glClearDepth(<clear>);
The command TraceAssertAttribMESA(DEPTH_BUFFER_BIT) will query the state
variables DEPTH_TEST, DEPTH_FUNC, DEPTH_WRITEMASK, and DEPTH_CLEAR_VALUE
to get the values <test>, <func>, <mask>, and <clear> respectively.
The resulting trace might then look will like this:
{
GLboolean b;
GLint i;
GLfloat f;
b = glIsEnabled(GL_DEPTH_TEST);
assert(b == <test>);
glGetIntegerv(GL_DEPTH_FUNC, &i);
assert(i == <func>);
glGetIntegerv(GL_DEPTH_MASK, &i);
assert(i == <mask>);
glGetFloatv(GL_DEPTH_CLEAR_VALUE, &f);
assert(f == <clear>);
}
Additions to Chapter 6 of the OpenGL 1.2.1 Specification
(State and State Requests)
Querying TRACE_MASK_MESA with GetIntegerv, GetFloatv, GetBooleanv or
GetDoublev returns the current command class trace mask.
Querying TRACE_NAME_MESA with GetString returns the current trace name.
Additions to Appendix A of the OpenGL 1.2.1 Specification (Invariance)
The MESA_trace extension can be used in a way that does not affect data
flow from application to OpenGL, as well as data flow from OpenGL to
application, except for timing, possible print I/O. TRACE_ERRORS_BIT_MESA
will add additional GetError queries. Setting a trace mask with NewTraceMESA
as well as use of TraceAssertAttribMESA might cause additional state queries.
With the possible exception of performance, OpenGL rendering should not be
affected at all by a properly chosen logging operation.
Additions to the AGL/GLX/WGL Specifications
None.
GLX Protocol
None. The logging operation is carried out client-side, by exporting
entry points to the wrapper functions that execute the logging operation.
Errors
INVALID_OPERATION is generated if any trace command except TraceCommentMESA
is called between Begin and End.
New State
The current trace name and current command class mask are stored
per-context.
New Implementation Dependent State
None.
Revision History
* Revision 0.1 - Initial draft from template (bk000415)
* Revision 0.2 - Draft (bk000906)
* Revision 0.3 - Draft (bk000913)
* Revision 0.4 - Reworked text, fixed typos (bp000914)
* Revision 0.5 - Assigned final GLenum values (bp001103)
* Revision 0.6 - TRACE_ERRORS_BIT_MESA (bk000916)
* Revision 0.7 - Added MESA postfix (bk010126)