* retrace OpenGL calls from a file;
-* visualize trace files, and inspect state.
+* inspect OpenGL state at any call while retracing;
+* visualize and edit trace files.
-Building from source
-====================
+Basic usage
+===========
-Requirements common for all platforms:
-* Python (requires version 2.6)
+Linux and Mac OS X
+------------------
-* CMake (tested with version 2.8)
+Run the application you want to trace as
-Requirements to build the GUI (optional):
+ /path/to/apitrace trace /path/to/application [args...]
-* Qt (tested with version 4.7)
+and it will generate a trace named `application.trace` in the current
+directory. You can specify the written trace filename by setting the
+`TRACE_FILE` environment variable before running.
-* QJSON (tested with version 0.7.1)
+View the trace with
+ /path/to/apitrace dump --color application.trace | less -R
-Linux / Mac OS X
-----------------
+Replay the trace with
-Build as:
+ /path/to/glretrace application.trace
- cmake -H. -Bbuild
- make -C build
+Pass the `-sb` option to use a single buffered visual. Pass `--help` to
+glretrace for more options.
-You can also build the 32bit GL wrapper on 64bit distro with a multilib gcc by
-doing:
+Start the GUI as
- cmake -H. -Bbuild32 -DCMAKE_C_FLAGS=-m32 -DCMAKE_CXX_FLAGS=-m32 -DCMAKE_EXE_LINKER_FLAGS=-m32
- make -C build32 glxtrace
+ /path/to/qapitrace application.trace
Windows
-------
-Additional requirements:
-
-* Microsoft Visual Studio (tested with 2008 version) or MinGW (tested with gcc version 4.4)
-
-* Microsoft DirectX SDK (tested with August 2007 release)
-
-To build with Visual Studio first invoke CMake GUI as:
-
- cmake-gui -H. -B%cd%\build
-
-and press the _Configure_ button.
+* Copy `opengl32.dll`, `d3d8.dll`, or `d3d9.dll` from build/wrappers directory
+ to the directory with the application you want to trace.
-It will try to detect most required/optional dependencies automatically. When
-not found automatically, you can manually specify the location of the
-dependencies from the GUI.
+* Run the application.
-If you are building with GUI support (i.e, with QT and QJSON), it should detect
-the official QT sdk automatically, but you will need to build QJSON yourself
-and also set the `QJSON_INCLUDE_DIR` and `QJSON_LIBRARIES` variables in the
-generated `CMakeCache.txt` when building apitrace and repeat the above
-sequence.
+* View the trace with
-After you've succesfully configured, you can start the build by opening the
-generated `build\apitrace.sln` solution file, or invoking `cmake` as:
+ \path\to\apitrace dump application.trace
- cmake --build build --config MinSizeRel
+* Replay the trace with
-The steps to build 64bit version are similar, but choosing _Visual Studio 9
-2008 Win64_ instead of _Visual Studio 9 2008_.
+ \path\to\glretrace application.trace
-It's also possible to instruct `cmake` build Windows binaries on Linux with
-[MinGW cross compilers](http://www.cmake.org/Wiki/CmakeMingw).
+Advanced command line usage
+===========================
-Usage
-=====
+Tracing manually
+----------------
-Linux
------
+### Linux ###
Run the application you want to trace as
- LD_PRELOAD=/path/to/glxtrace.so /path/to/application
+ LD_PRELOAD=/path/to/apitrace/wrappers/glxtrace.so /path/to/application
and it will generate a trace named `application.trace` in the current
directory. You can specify the written trace filename by setting the
`TRACE_FILE` environment variable before running.
-View the trace with
-
- /path/to/tracedump application.trace | less -R
-
-Replay the trace with
-
- /path/to/glretrace application.trace
-
-Pass the `-sb` option to use a single buffered visual. Pass `--help` to
-glretrace for more options.
-
-Start the GUI as
-
- /path/to/qapitrace application.trace
-
-
The `LD_PRELOAD` mechanism should work with most applications. There are some
applications, e.g., Unigine Heaven, which global function pointers with the
same name as GL entrypoints, living in a shared object that wasn't linked with
to trace by using `glxtrace.so` as an ordinary `libGL.so` and injecting into
`LD_LIBRARY_PATH`:
- ln -s glxtrace.so libGL.so
- ln -s glxtrace.so libGL.so.1
- ln -s glxtrace.so libGL.so.1.2
- export LD_LIBRARY_PATH=/path/to/directory/where/glxtrace/is:$LD_LIBRARY_PATH
+ ln -s glxtrace.so wrappers/libGL.so
+ ln -s glxtrace.so wrappers/libGL.so.1
+ ln -s glxtrace.so wrappers/libGL.so.1.2
+ export LD_LIBRARY_PATH=/path/to/apitrace/wrappers:$LD_LIBRARY_PATH
export TRACE_LIBGL=/path/to/real/libGL.so.1
/path/to/application
-See the 'ld.so' man page for more information about `LD_PRELOAD` and
+See the `ld.so` man page for more information about `LD_PRELOAD` and
`LD_LIBRARY_PATH` environment flags.
+### Mac OS X ###
+
+Run the application you want to trace as
+
+ DYLD_LIBRARY_PATH=/path/to/apitrace/wrappers /path/to/application
+
+Note that although Mac OS X has an `LD_PRELOAD` equivalent,
+`DYLD_INSERT_LIBRARIES`, it is mostly useless because it only works with
+`DYLD_FORCE_FLAT_NAMESPACE=1` which breaks most applications. See the `dyld` man
+page for more details about these environment flags.
+
+
+Emitting annotations to the trace from GL applications
+------------------------------------------------------
+
+You can emit string and frame annotations through the
+[`GL_GREMEDY_string_marker`](http://www.opengl.org/registry/specs/GREMEDY/string_marker.txt)
+and
+[`GL_GREMEDY_frame_terminator`](http://www.opengl.org/registry/specs/GREMEDY/frame_terminator.txt)
+GL extensions.
+
+**apitrace** will advertise and intercept these GL extensions independently of
+the GL implementation. So all you have to do is to use these extensions when
+available.
+
+For example, if you use [GLEW](http://glew.sourceforge.net/) to dynamically
+detect and use GL extensions, you could easily accomplish this by doing:
+
+ void foo() {
+
+ if (GLEW_GREMEDY_string_marker) {
+ glStringMarkerGREMEDY(0, __FUNCTION__ ": enter");
+ }
+
+ ...
+
+ if (GLEW_GREMEDY_string_marker) {
+ glStringMarkerGREMEDY(0, __FUNCTION__ ": leave");
+ }
+
+ }
+
+This has the added advantage of working equally well with gDEBugger.
+
+
+Dump GL state at a particular call
+----------------------------------
+
+You can get a dump of the bound GL state at call 12345 by doing:
+
+ /path/to/glretrace -D 12345 application.trace > 12345.json
+
+This is precisely the mechanism the GUI obtains its own state.
+
+You can compare two state dumps with the jsondiff.py script:
+
+ ./scripts/jsondiff.py 12345.json 67890.json
+
+
+Comparing two traces side by side
+---------------------------------
+
+ apitrace diff trace1.trace trace2.trace
+
+This works only on Unices, and it will truncate the traces due to performance
+limitations.
+
+
+Recording a video with FFmpeg
+-----------------------------
+
You can make a video of the output by doing
/path/to/glretrace -s - application.trace \
| ffmpeg -r 30 -f image2pipe -vcodec ppm -i pipe: -vcodec mpeg4 -y output.mp4
+Advanced usage for OpenGL implementors
+======================================
-Mac OS X
---------
+There are several advanced usage examples meant for OpenGL implementors.
-Usage on Mac OS X is similar to Linux above, except for the tracing procedure,
-which is instead:
- DYLD_LIBRARY_PATH=/path/to/apitrace/wrappers /path/to/application
+Regression testing
+------------------
-Note that although Mac OS X has an `LD_PRELOAD` equivalent,
-`DYLD_INSERT_LIBRARIES`, it is mostly useless because it only works with
-`DYLD_FORCE_FLAT_NAMESPACE=1` which breaks most applications. See the `dyld` man
-page for more details about these environment flags.
+These are the steps to create a regression test-suite around **apitrace**:
+* obtain a trace
-Windows
--------
+* obtain reference snapshots, by doing:
-* Copy `opengl32.dll`, `d3d8.dll`, or `d3d9.dll` from build/wrappers directory
- to the directory with the application you want to trace.
+ mkdir /path/to/snapshots/
+ /path/to/glretrace -s /path/to/reference/snapshots/ application.trace
-* Run the application.
+ on reference system.
-* View the trace with
+* prune the snapshots which are not interesting
- /path/to/tracedump application.trace
+* to do a regression test, do:
-* Replay the trace with
+ /path/to/glretrace -c /path/to/reference/snapshots/ application.trace
+
+ Alternatively, for a HTML summary, use the snapdiff script:
+
+ /path/to/glretrace -s /path/to/current/snapshots/ application.trace
+ ./scripts/snapdiff.py --output summary.html /path/to/reference/snapshots/ /path/to/current/snapshots/
+
+
+Automated git-bisection
+-----------------------
+
+With tracecheck.py it is possible to automate git bisect and pinpoint the
+commit responsible for a regression.
+
+Below is an example of using tracecheck.py to bisect a regression in the
+Mesa-based Intel 965 driver. But the procedure could be applied to any GL
+driver hosted on a git repository.
+
+First, create a build script, named build-script.sh, containing:
+
+ #!/bin/sh
+ set -e
+ export PATH=/usr/lib/ccache:$PATH
+ export CFLAGS='-g'
+ export CXXFLAGS='-g'
+ ./autogen.sh --disable-egl --disable-gallium --disable-glut --disable-glu --disable-glw --with-dri-drivers=i965
+ make clean
+ make "$@"
+
+It is important that builds are both robust, and efficient. Due to broken
+dependency discovery in Mesa's makefile system, it was necessary invoke `make
+clean` in every iteration step. `ccache` should be installed to avoid
+recompiling unchanged source files.
+
+Then do:
+
+ cd /path/to/mesa
+ export LIBGL_DEBUG=verbose
+ export LD_LIBRARY_PATH=$PWD/lib
+ export LIBGL_DRIVERS_DIR=$PWD/lib
+ git bisect start \
+ 6491e9593d5cbc5644eb02593a2f562447efdcbb 71acbb54f49089b03d3498b6f88c1681d3f649ac \
+ -- src/mesa/drivers/dri/intel src/mesa/drivers/dri/i965/
+ git bisect run /path/to/tracecheck.py \
+ --precision-threshold 8.0 \
+ --build /path/to/build-script.sh \
+ --gl-renderer '.*Mesa.*Intel.*' \
+ --retrace=/path/to/glretrace \
+ -c /path/to/reference/snapshots/ \
+ topogun-1.06-orc-84k.trace
+
+The trace-check.py script will skip automatically when there are build
+failures.
+
+The `--gl-renderer` option will also cause a commit to be skipped if the
+`GL_RENDERER` is unexpected (e.g., when a software renderer or another GL
+driver is unintentionally loaded due to missing symbol in the DRI driver, or
+another runtime fault).
+
+
+Side by side retracing
+----------------------
+
+In order to determine which draw call a regression first manifests one could
+generate snapshots for every draw call, using the `-S` option. That is, however,
+very inefficient for big traces with many draw calls.
+
+A faster approach is to run both the bad and a good GL driver side-by-side.
+The latter can be either a previously known good build of the GL driver, or a
+reference software renderer.
+
+This can be achieved with retracediff.py script, which invokes glretrace with
+different environments, allowing to choose the desired GL driver by
+manipulating variables such as `LD_LIBRARY_PATH` or `LIBGL_DRIVERS_DIR`.
+
+For example:
+
+ ./scripts/retracediff.py \
+ --ref-env LD_LIBRARY_PATH=/path/to/reference/GL/implementation \
+ -r ./glretrace \
+ --diff-prefix=/path/to/output/diffs \
+ application.trace
- /path/to/glretrace application.trace
Links
About **apitrace**:
+* [Official mailing list](http://lists.freedesktop.org/mailman/listinfo/apitrace)
+
* [Zack Rusin's blog introducing the GUI](http://zrusin.blogspot.com/2011/04/apitrace.html)
* [Jose's Fonseca blog introducing the tool](http://jrfonseca.blogspot.com/2008/07/tracing-d3d-applications.html)