4 **apitrace** consists of a set of tools to:
6 * trace OpenGL, OpenGL ES, Direct3D, and DirectDraw APIs calls to a file;
8 * retrace OpenGL and OpenGL ES calls from a file;
10 * inspect OpenGL state at any call while retracing;
12 * visualize and edit trace files.
14 See the [apitrace homepage](http://apitrace.github.com/) for more details.
17 Obtaining **apitrace**
18 ======================
20 To obtain apitrace either [download the latest
21 binaries](https://github.com/apitrace/apitrace/downloads) for your platform if
22 available, or follow the instructions in INSTALL.markdown to build it yourself.
23 On 64bits Linux and Windows platforms you'll need apitrace binaries that match
24 the architecture (32bits or 64bits) of the application being traced.
30 Run the application you want to trace as
32 apitrace trace --api API /path/to/application [args...]
34 and it will generate a trace named `application.trace` in the current
35 directory. You can specify the written trace filename by passing the
36 `--output` command line option.
38 Problems while tracing (e.g, if the application uses calls/parameters
39 unsupported by apitrace) will be reported via stderr output on Unices. On
40 Windows you'll need to run
41 [DebugView](http://technet.microsoft.com/en-us/sysinternals/bb896647) to view
44 Follow the "Tracing manually" instructions below if you cannot obtain a trace.
48 apitrace dump application.trace
50 Replay an OpenGL trace with
52 glretrace application.trace
54 Pass the `-sb` option to use a single buffered visual. Pass `--help` to
55 glretrace for more options.
63 qapitrace application.trace
65 You can also tell the GUI to go directly to a specific call
67 qapitrace application.trace 12345
70 Advanced command line usage
71 ===========================
77 Several tools take `CALLSET` arguments, e.g:
79 apitrace dump --calls CALLSET foo.trace
80 glretrace -S CALLSET foo.trace
82 The call syntax is very flexible. Here are a few examples:
86 * `1,2,4,5` set of calls
88 * `"1 2 4 5"` set of calls (commas are optional and can be replaced with whitespace)
90 * `1-100/2` calls 1, 3, 5, ..., 99
92 * `1-1000/draw` all draw calls between 1 and 1000
94 * `1-1000/fbo` all fbo changes between calls 1 and 1000
96 * `frame` all calls at end of frames
98 * `@foo.txt` read call numbers from `foo.txt`, using the same syntax as above
107 On 64 bits systems, you'll need to determine ether the application is 64 bits
108 or 32 bits. This can be done by doing
110 file /path/to/application
112 But beware of wrapper shell scripts -- what matters is the architecture of the
115 Run the application you want to trace as
117 LD_PRELOAD=/path/to/apitrace/wrappers/glxtrace.so /path/to/application
119 and it will generate a trace named `application.trace` in the current
120 directory. You can specify the written trace filename by setting the
121 `TRACE_FILE` environment variable before running.
123 The `LD_PRELOAD` mechanism should work with the majority applications. There
124 are some applications (e.g., Unigine Heaven, Android GPU emulator, etc.), that
125 have global function pointers with the same name as GL entrypoints, living in a
126 shared object that wasn't linked with `-Bsymbolic` flag, so relocations to
127 those globals function pointers get overwritten with the address to our wrapper
128 library, and the application will segfault when trying to write to them. For
129 these applications it is possible to trace by using `glxtrace.so` as an
130 ordinary `libGL.so` and injecting it via `LD_LIBRARY_PATH`:
132 ln -s glxtrace.so wrappers/libGL.so
133 ln -s glxtrace.so wrappers/libGL.so.1
134 ln -s glxtrace.so wrappers/libGL.so.1.2
135 export LD_LIBRARY_PATH=/path/to/apitrace/wrappers:$LD_LIBRARY_PATH
136 export TRACE_LIBGL=/path/to/real/libGL.so.1
139 If you are an application developer, you can avoid this either by linking with
140 `-Bsymbolic` flag, or by using some unique prefix for your function pointers.
142 See the `ld.so` man page for more information about `LD_PRELOAD` and
143 `LD_LIBRARY_PATH` environment flags.
145 To trace the application inside gdb, invoke gdb as:
147 gdb --ex 'set exec-wrapper env LD_PRELOAD=/path/to/glxtrace.so' --args /path/to/application
151 The following instructions should work at least for Android Ice Scream
154 For standalone applications the instructions above for Linux should
155 work. To trace applications started from within the Android VM process
156 (`app_process` aka zygote) you'll have to wrap this process and enable
157 tracing dynamically for the application to be traced.
159 - Wrapping the android main VM process:
161 In the Android root /init.rc add the `LD_PRELOAD` setting to zygote's
162 environment in the 'service zygote' section:
165 setenv LD_PRELOAD /data/egltrace.so
168 Note that ICS will overwrite the /init.rc during each boot with the
169 version in the recovery image. So you'll have to change the file in
170 your ICS source tree, rebuild and reflash the device.
171 Rebuilding/reflashing only the recovery image should be sufficient.
173 - Copy egltrace.so to /data
177 adb push /path/to/apitrace/build/wrappers/egltrace.so /data
179 - Adjust file permissions to store the trace file:
181 By default egltrace.so will store the trace in
182 `/data/app_process.trace`. For this to work for applications running
183 with a uid other than 0, you have to allow writes to the `/data`
184 directory on the device:
188 - Enable tracing for a specific process name:
190 To trace for example the Settings application:
192 setprop debug.apitrace.procname com.android.settings
194 In general this name will match what `ps` reports.
196 - Start the application:
198 If the application was already running, for example due to ICS's way
199 of pre-starting the apps, you might have to kill the application
204 Launch the application for example from the application menu.
208 Run the application you want to trace as
210 DYLD_LIBRARY_PATH=/path/to/apitrace/wrappers /path/to/application
212 Note that although Mac OS X has an `LD_PRELOAD` equivalent,
213 `DYLD_INSERT_LIBRARIES`, it is mostly useless because it only works with
214 `DYLD_FORCE_FLAT_NAMESPACE=1` which breaks most applications. See the `dyld` man
215 page for more details about these environment flags.
219 When tracing third-party applications, you can identify the target
220 application's main executable, either by:
222 * right clicking on the application's icon in the _Start Menu_, choose
223 _Properties_, and see the _Target_ field;
225 * or by starting the application, run Windows Task Manager (taskmgr.exe), right
226 click on the application name in the _Applications_ tab, choose _Go To Process_,
227 note the highlighted _Image Name_, and search it on `C:\Program Files` or
228 `C:\Program Files (x86)`.
230 On 64 bits Windows, you'll need to determine ether the application is a 64 bits
231 or 32 bits. 32 bits applications will have a `*32` suffix in the _Image Name_
232 column of the _Processes_ tab of _Windows Task Manager_ window.
234 Copy the appropriate `opengl32.dll`, `d3d8.dll`, or `d3d9.dll` from the
235 wrappers directory to the directory with the application you want to trace.
236 Then run the application as usual.
238 You can specify the written trace filename by setting the `TRACE_FILE`
239 environment variable before running.
242 Emitting annotations to the trace
243 ---------------------------------
245 From OpenGL applications you can embed annotations in the trace file through the
246 [`GL_GREMEDY_string_marker`](http://www.opengl.org/registry/specs/GREMEDY/string_marker.txt)
248 [`GL_GREMEDY_frame_terminator`](http://www.opengl.org/registry/specs/GREMEDY/frame_terminator.txt)
251 **apitrace** will advertise and intercept these GL extensions independently of
252 the GL implementation. So all you have to do is to use these extensions when
255 For example, if you use [GLEW](http://glew.sourceforge.net/) to dynamically
256 detect and use GL extensions, you could easily accomplish this by doing:
260 if (GLEW_GREMEDY_string_marker) {
261 glStringMarkerGREMEDY(0, __FUNCTION__ ": enter");
266 if (GLEW_GREMEDY_string_marker) {
267 glStringMarkerGREMEDY(0, __FUNCTION__ ": leave");
272 This has the added advantage of working equally well with gDEBugger.
275 From OpenGL ES applications you can embed annotations in the trace file through the
276 [`GL_EXT_debug_marker`](http://www.khronos.org/registry/gles/extensions/EXT/EXT_debug_marker.txt)
280 For Direct3D applications you can follow the same procedure used for
281 [instrumenting an application for PIX](http://technet.microsoft.com/en-us/query/ee417250)
284 Dump GL state at a particular call
285 ----------------------------------
287 You can get a dump of the bound GL state at call 12345 by doing:
289 glretrace -D 12345 application.trace > 12345.json
291 This is precisely the mechanism the GUI obtains its own state.
293 You can compare two state dumps by doing:
295 apitrace diff-state 12345.json 67890.json
298 Comparing two traces side by side
299 ---------------------------------
301 apitrace diff trace1.trace trace2.trace
303 This works only on Unices, and it will truncate the traces due to performance
307 Recording a video with FFmpeg
308 -----------------------------
310 You can make a video of the output by doing
312 glretrace -s - application.trace \
313 | ffmpeg -r 30 -f image2pipe -vcodec ppm -i pipe: -vcodec mpeg4 -y output.mp4
319 You can make a smaller trace by doing:
321 apitrace trim --callset 100-1000 -o trimed.trace applicated.trace
323 If you need precise control over which calls to trim you can specify the
324 individual call numbers a plaintext file, as described in the 'Call sets'
331 You can perform gpu and cpu profiling with the command line options:
333 * `-pgpu` record gpu times for frames and draw calls.
335 * `-pcpu` record cpu times for frames and draw calls.
337 * `-ppd` record pixels drawn for each draw call.
339 The results from this can then be read by hand or analysed with a script.
341 `scripts/profileshader.py` will read the profile results and format them into a
342 table which displays profiling results per shader.
344 For example, to record all profiling data and utilise the per shader script:
346 ./glretrace -pgpu -pcpu -ppd foo.trace | ./scripts/profileshader.py
349 Advanced usage for OpenGL implementors
350 ======================================
352 There are several advanced usage examples meant for OpenGL implementors.
358 These are the steps to create a regression test-suite around **apitrace**:
362 * obtain reference snapshots, by doing on a reference system:
364 mkdir /path/to/reference/snapshots/
365 glretrace -s /path/to/reference/snapshots/ application.trace
367 * prune the snapshots which are not interesting
369 * to do a regression test, do:
371 glretrace -c /path/to/reference/snapshots/ application.trace
373 Alternatively, for a HTML summary, use `apitrace diff-images`:
375 glretrace -s /path/to/test/snapshots/ application.trace
376 apitrace diff-images --output summary.html /path/to/reference/snapshots/ /path/to/test/snapshots/
379 Automated git-bisection
380 -----------------------
382 With tracecheck.py it is possible to automate git bisect and pinpoint the
383 commit responsible for a regression.
385 Below is an example of using tracecheck.py to bisect a regression in the
386 Mesa-based Intel 965 driver. But the procedure could be applied to any GL
387 driver hosted on a git repository.
389 First, create a build script, named build-script.sh, containing:
393 export PATH=/usr/lib/ccache:$PATH
396 ./autogen.sh --disable-egl --disable-gallium --disable-glut --disable-glu --disable-glw --with-dri-drivers=i965
400 It is important that builds are both robust, and efficient. Due to broken
401 dependency discovery in Mesa's makefile system, it was necessary invoke `make
402 clean` in every iteration step. `ccache` should be installed to avoid
403 recompiling unchanged source files.
408 export LIBGL_DEBUG=verbose
409 export LD_LIBRARY_PATH=$PWD/lib
410 export LIBGL_DRIVERS_DIR=$PWD/lib
412 6491e9593d5cbc5644eb02593a2f562447efdcbb 71acbb54f49089b03d3498b6f88c1681d3f649ac \
413 -- src/mesa/drivers/dri/intel src/mesa/drivers/dri/i965/
414 git bisect run /path/to/tracecheck.py \
415 --precision-threshold 8.0 \
416 --build /path/to/build-script.sh \
417 --gl-renderer '.*Mesa.*Intel.*' \
418 --retrace=/path/to/glretrace \
419 -c /path/to/reference/snapshots/ \
420 topogun-1.06-orc-84k.trace
422 The trace-check.py script will skip automatically when there are build
425 The `--gl-renderer` option will also cause a commit to be skipped if the
426 `GL_RENDERER` is unexpected (e.g., when a software renderer or another GL
427 driver is unintentionally loaded due to missing symbol in the DRI driver, or
428 another runtime fault).
431 Side by side retracing
432 ----------------------
434 In order to determine which draw call a regression first manifests one could
435 generate snapshots for every draw call, using the `-S` option. That is, however,
436 very inefficient for big traces with many draw calls.
438 A faster approach is to run both the bad and a good GL driver side-by-side.
439 The latter can be either a previously known good build of the GL driver, or a
440 reference software renderer.
442 This can be achieved with retracediff.py script, which invokes glretrace with
443 different environments, allowing to choose the desired GL driver by
444 manipulating variables such as `LD_LIBRARY_PATH`, `LIBGL_DRIVERS_DIR`, or
447 For example, on Linux:
449 ./scripts/retracediff.py \
450 --ref-env LD_LIBRARY_PATH=/path/to/reference/GL/implementation \
451 --retrace /path/to/glretrace \
452 --diff-prefix=/path/to/output/diffs \
457 python scripts\retracediff.py --retrace \path\to\glretrace.exe --ref-env TRACE_LIBGL=\path\to\reference\opengl32.dll application.trace
465 * [Official mailing list](http://lists.freedesktop.org/mailman/listinfo/apitrace)
467 * [Zack Rusin's blog introducing the GUI](http://zrusin.blogspot.com/2011/04/apitrace.html)
469 * [Jose's Fonseca blog introducing the tool](http://jrfonseca.blogspot.com/2008/07/tracing-d3d-applications.html)
477 * [Proxy DLL](http://www.mikoweb.eu/index.php?node=21)
479 * [Intercept Calls to DirectX with a Proxy DLL](http://www.codeguru.com/cpp/g-m/directx/directx8/article.php/c11453/)
481 * [Direct3D 9 API Interceptor](http://graphics.stanford.edu/~mdfisher/D3D9Interceptor.html)
485 * [Microsoft PIX](http://msdn.microsoft.com/en-us/library/ee417062.aspx)
487 * [D3DSpy](http://doc.51windows.net/Directx9_SDK/?url=/directx9_sdk/graphics/programmingguide/TutorialsAndSamplesAndToolsAndTips/Tools/D3DSpy.htm): the predecessor of PIX
489 * [NVIDIA PerfKit](http://developer.nvidia.com/nvidia-perfkit)
491 * [AMD GPU PerfStudio](http://developer.amd.com/gpu/PerfStudio/pages/APITraceWindow.aspx)
493 * [Intel Graphics Performance Analyzers](http://www.intel.com/software/gpa/)
501 * [BuGLe](http://www.opengl.org/sdk/tools/BuGLe/)
503 * [GLIntercept](http://code.google.com/p/glintercept/)
505 * [tracy](https://gitorious.org/tracy): OpenGL ES and OpenVG trace, retrace, and state inspection
507 * [WebGL-Inspector](http://benvanik.github.com/WebGL-Inspector/)
511 * [AMD CodeXL](http://developer.amd.com/tools/hc/CodeXL/Pages/default.aspx)
513 * [AMD GPU PerfStudio](http://developer.amd.com/gpu/PerfStudio/pages/APITraceWindow.aspx)
515 * [gDEBugger](http://www.gremedy.com/products.php) and [AMD gDEBugger](http://developer.amd.com/tools/gDEBugger/Pages/default.aspx)
517 * [glslDevil](http://cumbia.informatik.uni-stuttgart.de/glsldevil/index.html)