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 apitrace retrace application.trace
54 Pass the `--sb` option to use a single buffered visual. Pass `--help` to
55 `apitrace retrace` 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 apitrace dump-images --calls=CALLSET foo.trace
82 The call syntax is very flexible. Here are a few examples:
86 * `0,2,4,5` set of calls
88 * `"0 2 4 5"` set of calls (commas are optional and can be replaced with whitespace)
90 * `0-100/2` calls 1, 3, 5, ..., 99
92 * `0-1000/draw` all draw calls between 0 and 1000
94 * `0-1000/fbo` all fbo changes between calls 0 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 GLX 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 For EGL applications you will need to use `egltrace.so` instead of
126 The `LD_PRELOAD` mechanism should work with the majority applications. There
127 are some applications (e.g., Unigine Heaven, Android GPU emulator, etc.), that
128 have global function pointers with the same name as GL entrypoints, living in a
129 shared object that wasn't linked with `-Bsymbolic` flag, so relocations to
130 those globals function pointers get overwritten with the address to our wrapper
131 library, and the application will segfault when trying to write to them. For
132 these applications it is possible to trace by using `glxtrace.so` as an
133 ordinary `libGL.so` and injecting it via `LD_LIBRARY_PATH`:
135 ln -s glxtrace.so wrappers/libGL.so
136 ln -s glxtrace.so wrappers/libGL.so.1
137 ln -s glxtrace.so wrappers/libGL.so.1.2
138 export LD_LIBRARY_PATH=/path/to/apitrace/wrappers:$LD_LIBRARY_PATH
139 export TRACE_LIBGL=/path/to/real/libGL.so.1
142 If you are an application developer, you can avoid this either by linking with
143 `-Bsymbolic` flag, or by using some unique prefix for your function pointers.
145 See the `ld.so` man page for more information about `LD_PRELOAD` and
146 `LD_LIBRARY_PATH` environment flags.
148 To trace the application inside gdb, invoke gdb as:
150 gdb --ex 'set exec-wrapper env LD_PRELOAD=/path/to/glxtrace.so' --args /path/to/application
154 The following instructions should work at least for Android Ice Scream
157 For standalone applications the instructions above for Linux should
158 work. To trace applications started from within the Android VM process
159 (`app_process` aka zygote) you'll have to wrap this process and enable
160 tracing dynamically for the application to be traced.
162 - Wrapping the android main VM process:
164 In the Android root /init.rc add the `LD_PRELOAD` setting to zygote's
165 environment in the 'service zygote' section:
168 setenv LD_PRELOAD /data/egltrace.so
171 Note that ICS will overwrite the /init.rc during each boot with the
172 version in the recovery image. So you'll have to change the file in
173 your ICS source tree, rebuild and reflash the device.
174 Rebuilding/reflashing only the recovery image should be sufficient.
176 - Copy egltrace.so to /data
180 adb push /path/to/apitrace/build/wrappers/egltrace.so /data
182 - Adjust file permissions to store the trace file:
184 By default egltrace.so will store the trace in
185 `/data/app_process.trace`. For this to work for applications running
186 with a uid other than 0, you have to allow writes to the `/data`
187 directory on the device:
191 - Enable tracing for a specific process name:
193 To trace for example the Settings application:
195 setprop debug.apitrace.procname com.android.settings
197 In general this name will match what `ps` reports.
199 - Start the application:
201 If the application was already running, for example due to ICS's way
202 of pre-starting the apps, you might have to kill the application
207 Launch the application for example from the application menu.
211 Run the application you want to trace as
213 DYLD_LIBRARY_PATH=/path/to/apitrace/wrappers /path/to/application
215 Note that although Mac OS X has an `LD_PRELOAD` equivalent,
216 `DYLD_INSERT_LIBRARIES`, it is mostly useless because it only works with
217 `DYLD_FORCE_FLAT_NAMESPACE=1` which breaks most applications. See the `dyld` man
218 page for more details about these environment flags.
222 When tracing third-party applications, you can identify the target
223 application's main executable, either by:
225 * right clicking on the application's icon in the _Start Menu_, choose
226 _Properties_, and see the _Target_ field;
228 * or by starting the application, run Windows Task Manager (taskmgr.exe), right
229 click on the application name in the _Applications_ tab, choose _Go To Process_,
230 note the highlighted _Image Name_, and search it on `C:\Program Files` or
231 `C:\Program Files (x86)`.
233 On 64 bits Windows, you'll need to determine ether the application is a 64 bits
234 or 32 bits. 32 bits applications will have a `*32` suffix in the _Image Name_
235 column of the _Processes_ tab of _Windows Task Manager_ window.
237 Copy the appropriate `opengl32.dll`, `d3d8.dll`, or `d3d9.dll` from the
238 wrappers directory to the directory with the application you want to trace.
239 Then run the application as usual.
241 You can specify the written trace filename by setting the `TRACE_FILE`
242 environment variable before running.
245 Emitting annotations to the trace
246 ---------------------------------
248 From OpenGL applications you can embed annotations in the trace file through the
249 [`GL_GREMEDY_string_marker`](http://www.opengl.org/registry/specs/GREMEDY/string_marker.txt)
251 [`GL_GREMEDY_frame_terminator`](http://www.opengl.org/registry/specs/GREMEDY/frame_terminator.txt)
254 **apitrace** will advertise and intercept these GL extensions independently of
255 the GL implementation. So all you have to do is to use these extensions when
258 For example, if you use [GLEW](http://glew.sourceforge.net/) to dynamically
259 detect and use GL extensions, you could easily accomplish this by doing:
263 if (GLEW_GREMEDY_string_marker) {
264 glStringMarkerGREMEDY(0, __FUNCTION__ ": enter");
269 if (GLEW_GREMEDY_string_marker) {
270 glStringMarkerGREMEDY(0, __FUNCTION__ ": leave");
275 This has the added advantage of working equally well with gDEBugger.
278 From OpenGL ES applications you can embed annotations in the trace file through the
279 [`GL_EXT_debug_marker`](http://www.khronos.org/registry/gles/extensions/EXT/EXT_debug_marker.txt)
283 For Direct3D applications you can follow the standard procedure for
284 [adding user defined events to Visual Studio Graphics Debugger / PIX](http://msdn.microsoft.com/en-us/library/vstudio/hh873200.aspx):
286 - `D3DPERF_BeginEvent`, `D3DPERF_EndEvent`, and `D3DPERF_SetMarker` for D3D9 applications.
288 - `ID3DUserDefinedAnnotation::BeginEvent`,
289 `ID3DUserDefinedAnnotation::EndEvent`, and
290 `ID3DUserDefinedAnnotation::SetMarker` for D3D11.1 applications.
293 Dump GL state at a particular call
294 ----------------------------------
296 You can get a dump of the bound GL state at call 12345 by doing:
298 apitrace retrace -D 12345 application.trace > 12345.json
300 This is precisely the mechanism the GUI obtains its own state.
302 You can compare two state dumps by doing:
304 apitrace diff-state 12345.json 67890.json
307 Comparing two traces side by side
308 ---------------------------------
310 apitrace diff trace1.trace trace2.trace
312 This works only on Unices, and it will truncate the traces due to performance
316 Recording a video with FFmpeg
317 -----------------------------
319 You can make a video of the output by doing
321 apitrace dump-images -o - application.trace \
322 | ffmpeg -r 30 -f image2pipe -vcodec ppm -i pipe: -vcodec mpeg4 -y output.mp4
328 You can make a smaller trace by doing:
330 apitrace trim --callset 100-1000 -o trimed.trace applicated.trace
332 If you need precise control over which calls to trim you can specify the
333 individual call numbers a plaintext file, as described in the 'Call sets'
340 You can perform gpu and cpu profiling with the command line options:
342 * `--pgpu` record gpu times for frames and draw calls.
344 * `--pcpu` record cpu times for frames and draw calls.
346 * `--ppd` record pixels drawn for each draw call.
348 The results from this can then be read by hand or analysed with a script.
350 `scripts/profileshader.py` will read the profile results and format them into a
351 table which displays profiling results per shader.
353 For example, to record all profiling data and utilise the per shader script:
355 apitrace retrace --pgpu --pcpu --ppd foo.trace | ./scripts/profileshader.py
358 Advanced usage for OpenGL implementors
359 ======================================
361 There are several advanced usage examples meant for OpenGL implementors.
367 These are the steps to create a regression test-suite around **apitrace**:
371 * obtain reference snapshots, by doing on a reference system:
373 mkdir /path/to/reference/snapshots/
374 apitrace dump-images -o /path/to/reference/snapshots/ application.trace
376 * prune the snapshots which are not interesting
378 * to do a regression test, use `apitrace diff-images`:
380 apitrace dump-images -o /path/to/test/snapshots/ application.trace
381 apitrace diff-images --output summary.html /path/to/reference/snapshots/ /path/to/test/snapshots/
384 Automated git-bisection
385 -----------------------
387 With tracecheck.py it is possible to automate git bisect and pinpoint the
388 commit responsible for a regression.
390 Below is an example of using tracecheck.py to bisect a regression in the
391 Mesa-based Intel 965 driver. But the procedure could be applied to any GL
392 driver hosted on a git repository.
394 First, create a build script, named build-script.sh, containing:
398 export PATH=/usr/lib/ccache:$PATH
401 ./autogen.sh --disable-egl --disable-gallium --disable-glut --disable-glu --disable-glw --with-dri-drivers=i965
405 It is important that builds are both robust, and efficient. Due to broken
406 dependency discovery in Mesa's makefile system, it was necessary invoke `make
407 clean` in every iteration step. `ccache` should be installed to avoid
408 recompiling unchanged source files.
413 export LIBGL_DEBUG=verbose
414 export LD_LIBRARY_PATH=$PWD/lib
415 export LIBGL_DRIVERS_DIR=$PWD/lib
417 6491e9593d5cbc5644eb02593a2f562447efdcbb 71acbb54f49089b03d3498b6f88c1681d3f649ac \
418 -- src/mesa/drivers/dri/intel src/mesa/drivers/dri/i965/
419 git bisect run /path/to/tracecheck.py \
420 --precision-threshold 8.0 \
421 --build /path/to/build-script.sh \
422 --gl-renderer '.*Mesa.*Intel.*' \
423 --retrace=/path/to/glretrace \
424 -c /path/to/reference/snapshots/ \
425 topogun-1.06-orc-84k.trace
427 The trace-check.py script will skip automatically when there are build
430 The `--gl-renderer` option will also cause a commit to be skipped if the
431 `GL_RENDERER` is unexpected (e.g., when a software renderer or another GL
432 driver is unintentionally loaded due to missing symbol in the DRI driver, or
433 another runtime fault).
436 Side by side retracing
437 ----------------------
439 In order to determine which draw call a regression first manifests one could
440 generate snapshots for every draw call, using the `-S` option. That is, however,
441 very inefficient for big traces with many draw calls.
443 A faster approach is to run both the bad and a good GL driver side-by-side.
444 The latter can be either a previously known good build of the GL driver, or a
445 reference software renderer.
447 This can be achieved with retracediff.py script, which invokes glretrace with
448 different environments, allowing to choose the desired GL driver by
449 manipulating variables such as `LD_LIBRARY_PATH`, `LIBGL_DRIVERS_DIR`, or
452 For example, on Linux:
454 ./scripts/retracediff.py \
455 --ref-env LD_LIBRARY_PATH=/path/to/reference/GL/implementation \
456 --retrace /path/to/glretrace \
457 --diff-prefix=/path/to/output/diffs \
462 python scripts\retracediff.py --retrace \path\to\glretrace.exe --ref-env TRACE_LIBGL=\path\to\reference\opengl32.dll application.trace
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