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.
57 EGL traces must be replayed with `eglretrace` instead of `glretrace`.
65 qapitrace application.trace
67 You can also tell the GUI to go directly to a specific call
69 qapitrace application.trace 12345
72 Advanced command line usage
73 ===========================
79 Several tools take `CALLSET` arguments, e.g:
81 apitrace dump --calls CALLSET foo.trace
82 glretrace -S CALLSET foo.trace
84 The call syntax is very flexible. Here are a few examples:
88 * `0,2,4,5` set of calls
90 * `"0 2 4 5"` set of calls (commas are optional and can be replaced with whitespace)
92 * `0-100/2` calls 1, 3, 5, ..., 99
94 * `0-1000/draw` all draw calls between 0 and 1000
96 * `0-1000/fbo` all fbo changes between calls 0 and 1000
98 * `frame` all calls at end of frames
100 * `@foo.txt` read call numbers from `foo.txt`, using the same syntax as above
109 On 64 bits systems, you'll need to determine ether the application is 64 bits
110 or 32 bits. This can be done by doing
112 file /path/to/application
114 But beware of wrapper shell scripts -- what matters is the architecture of the
117 Run the GLX application you want to trace as
119 LD_PRELOAD=/path/to/apitrace/wrappers/glxtrace.so /path/to/application
121 and it will generate a trace named `application.trace` in the current
122 directory. You can specify the written trace filename by setting the
123 `TRACE_FILE` environment variable before running.
125 For EGL applications you will need to use `egltrace.so` instead of
128 The `LD_PRELOAD` mechanism should work with the majority applications. There
129 are some applications (e.g., Unigine Heaven, Android GPU emulator, etc.), that
130 have global function pointers with the same name as GL entrypoints, living in a
131 shared object that wasn't linked with `-Bsymbolic` flag, so relocations to
132 those globals function pointers get overwritten with the address to our wrapper
133 library, and the application will segfault when trying to write to them. For
134 these applications it is possible to trace by using `glxtrace.so` as an
135 ordinary `libGL.so` and injecting it via `LD_LIBRARY_PATH`:
137 ln -s glxtrace.so wrappers/libGL.so
138 ln -s glxtrace.so wrappers/libGL.so.1
139 ln -s glxtrace.so wrappers/libGL.so.1.2
140 export LD_LIBRARY_PATH=/path/to/apitrace/wrappers:$LD_LIBRARY_PATH
141 export TRACE_LIBGL=/path/to/real/libGL.so.1
144 If you are an application developer, you can avoid this either by linking with
145 `-Bsymbolic` flag, or by using some unique prefix for your function pointers.
147 See the `ld.so` man page for more information about `LD_PRELOAD` and
148 `LD_LIBRARY_PATH` environment flags.
150 To trace the application inside gdb, invoke gdb as:
152 gdb --ex 'set exec-wrapper env LD_PRELOAD=/path/to/glxtrace.so' --args /path/to/application
156 The following instructions should work at least for Android Ice Scream
159 For standalone applications the instructions above for Linux should
160 work. To trace applications started from within the Android VM process
161 (`app_process` aka zygote) you'll have to wrap this process and enable
162 tracing dynamically for the application to be traced.
164 - Wrapping the android main VM process:
166 In the Android root /init.rc add the `LD_PRELOAD` setting to zygote's
167 environment in the 'service zygote' section:
170 setenv LD_PRELOAD /data/egltrace.so
173 Note that ICS will overwrite the /init.rc during each boot with the
174 version in the recovery image. So you'll have to change the file in
175 your ICS source tree, rebuild and reflash the device.
176 Rebuilding/reflashing only the recovery image should be sufficient.
178 - Copy egltrace.so to /data
182 adb push /path/to/apitrace/build/wrappers/egltrace.so /data
184 - Adjust file permissions to store the trace file:
186 By default egltrace.so will store the trace in
187 `/data/app_process.trace`. For this to work for applications running
188 with a uid other than 0, you have to allow writes to the `/data`
189 directory on the device:
193 - Enable tracing for a specific process name:
195 To trace for example the Settings application:
197 setprop debug.apitrace.procname com.android.settings
199 In general this name will match what `ps` reports.
201 - Start the application:
203 If the application was already running, for example due to ICS's way
204 of pre-starting the apps, you might have to kill the application
209 Launch the application for example from the application menu.
213 Run the application you want to trace as
215 DYLD_LIBRARY_PATH=/path/to/apitrace/wrappers /path/to/application
217 Note that although Mac OS X has an `LD_PRELOAD` equivalent,
218 `DYLD_INSERT_LIBRARIES`, it is mostly useless because it only works with
219 `DYLD_FORCE_FLAT_NAMESPACE=1` which breaks most applications. See the `dyld` man
220 page for more details about these environment flags.
224 When tracing third-party applications, you can identify the target
225 application's main executable, either by:
227 * right clicking on the application's icon in the _Start Menu_, choose
228 _Properties_, and see the _Target_ field;
230 * or by starting the application, run Windows Task Manager (taskmgr.exe), right
231 click on the application name in the _Applications_ tab, choose _Go To Process_,
232 note the highlighted _Image Name_, and search it on `C:\Program Files` or
233 `C:\Program Files (x86)`.
235 On 64 bits Windows, you'll need to determine ether the application is a 64 bits
236 or 32 bits. 32 bits applications will have a `*32` suffix in the _Image Name_
237 column of the _Processes_ tab of _Windows Task Manager_ window.
239 Copy the appropriate `opengl32.dll`, `d3d8.dll`, or `d3d9.dll` from the
240 wrappers directory to the directory with the application you want to trace.
241 Then run the application as usual.
243 You can specify the written trace filename by setting the `TRACE_FILE`
244 environment variable before running.
247 Emitting annotations to the trace
248 ---------------------------------
250 From OpenGL applications you can embed annotations in the trace file through the
251 [`GL_GREMEDY_string_marker`](http://www.opengl.org/registry/specs/GREMEDY/string_marker.txt)
253 [`GL_GREMEDY_frame_terminator`](http://www.opengl.org/registry/specs/GREMEDY/frame_terminator.txt)
256 **apitrace** will advertise and intercept these GL extensions independently of
257 the GL implementation. So all you have to do is to use these extensions when
260 For example, if you use [GLEW](http://glew.sourceforge.net/) to dynamically
261 detect and use GL extensions, you could easily accomplish this by doing:
265 if (GLEW_GREMEDY_string_marker) {
266 glStringMarkerGREMEDY(0, __FUNCTION__ ": enter");
271 if (GLEW_GREMEDY_string_marker) {
272 glStringMarkerGREMEDY(0, __FUNCTION__ ": leave");
277 This has the added advantage of working equally well with gDEBugger.
280 From OpenGL ES applications you can embed annotations in the trace file through the
281 [`GL_EXT_debug_marker`](http://www.khronos.org/registry/gles/extensions/EXT/EXT_debug_marker.txt)
285 For Direct3D applications you can follow the standard procedure for
286 [adding user defined events to Visual Studio Graphics Debugger / PIX](http://msdn.microsoft.com/en-us/library/vstudio/hh873200.aspx):
288 - `D3DPERF_BeginEvent`, `D3DPERF_EndEvent`, and `D3DPERF_SetMarker` for D3D9 applications.
290 - `ID3DUserDefinedAnnotation::BeginEvent`,
291 `ID3DUserDefinedAnnotation::EndEvent`, and
292 `ID3DUserDefinedAnnotation::SetMarker` for D3D11.1 applications.
295 Dump GL state at a particular call
296 ----------------------------------
298 You can get a dump of the bound GL state at call 12345 by doing:
300 glretrace -D 12345 application.trace > 12345.json
302 This is precisely the mechanism the GUI obtains its own state.
304 You can compare two state dumps by doing:
306 apitrace diff-state 12345.json 67890.json
309 Comparing two traces side by side
310 ---------------------------------
312 apitrace diff trace1.trace trace2.trace
314 This works only on Unices, and it will truncate the traces due to performance
318 Recording a video with FFmpeg
319 -----------------------------
321 You can make a video of the output by doing
323 glretrace -s - application.trace \
324 | ffmpeg -r 30 -f image2pipe -vcodec ppm -i pipe: -vcodec mpeg4 -y output.mp4
330 You can make a smaller trace by doing:
332 apitrace trim --callset 100-1000 -o trimed.trace applicated.trace
334 If you need precise control over which calls to trim you can specify the
335 individual call numbers a plaintext file, as described in the 'Call sets'
342 You can perform gpu and cpu profiling with the command line options:
344 * `--pgpu` record gpu times for frames and draw calls.
346 * `--pcpu` record cpu times for frames and draw calls.
348 * `--ppd` record pixels drawn for each draw call.
350 The results from this can then be read by hand or analysed with a script.
352 `scripts/profileshader.py` will read the profile results and format them into a
353 table which displays profiling results per shader.
355 For example, to record all profiling data and utilise the per shader script:
357 ./glretrace --pgpu --pcpu --ppd foo.trace | ./scripts/profileshader.py
360 Advanced usage for OpenGL implementors
361 ======================================
363 There are several advanced usage examples meant for OpenGL implementors.
369 These are the steps to create a regression test-suite around **apitrace**:
373 * obtain reference snapshots, by doing on a reference system:
375 mkdir /path/to/reference/snapshots/
376 glretrace -s /path/to/reference/snapshots/ application.trace
378 * prune the snapshots which are not interesting
380 * to do a regression test, do:
382 glretrace -c /path/to/reference/snapshots/ application.trace
384 Alternatively, for a HTML summary, use `apitrace diff-images`:
386 glretrace -s /path/to/test/snapshots/ application.trace
387 apitrace diff-images --output summary.html /path/to/reference/snapshots/ /path/to/test/snapshots/
390 Automated git-bisection
391 -----------------------
393 With tracecheck.py it is possible to automate git bisect and pinpoint the
394 commit responsible for a regression.
396 Below is an example of using tracecheck.py to bisect a regression in the
397 Mesa-based Intel 965 driver. But the procedure could be applied to any GL
398 driver hosted on a git repository.
400 First, create a build script, named build-script.sh, containing:
404 export PATH=/usr/lib/ccache:$PATH
407 ./autogen.sh --disable-egl --disable-gallium --disable-glut --disable-glu --disable-glw --with-dri-drivers=i965
411 It is important that builds are both robust, and efficient. Due to broken
412 dependency discovery in Mesa's makefile system, it was necessary invoke `make
413 clean` in every iteration step. `ccache` should be installed to avoid
414 recompiling unchanged source files.
419 export LIBGL_DEBUG=verbose
420 export LD_LIBRARY_PATH=$PWD/lib
421 export LIBGL_DRIVERS_DIR=$PWD/lib
423 6491e9593d5cbc5644eb02593a2f562447efdcbb 71acbb54f49089b03d3498b6f88c1681d3f649ac \
424 -- src/mesa/drivers/dri/intel src/mesa/drivers/dri/i965/
425 git bisect run /path/to/tracecheck.py \
426 --precision-threshold 8.0 \
427 --build /path/to/build-script.sh \
428 --gl-renderer '.*Mesa.*Intel.*' \
429 --retrace=/path/to/glretrace \
430 -c /path/to/reference/snapshots/ \
431 topogun-1.06-orc-84k.trace
433 The trace-check.py script will skip automatically when there are build
436 The `--gl-renderer` option will also cause a commit to be skipped if the
437 `GL_RENDERER` is unexpected (e.g., when a software renderer or another GL
438 driver is unintentionally loaded due to missing symbol in the DRI driver, or
439 another runtime fault).
442 Side by side retracing
443 ----------------------
445 In order to determine which draw call a regression first manifests one could
446 generate snapshots for every draw call, using the `-S` option. That is, however,
447 very inefficient for big traces with many draw calls.
449 A faster approach is to run both the bad and a good GL driver side-by-side.
450 The latter can be either a previously known good build of the GL driver, or a
451 reference software renderer.
453 This can be achieved with retracediff.py script, which invokes glretrace with
454 different environments, allowing to choose the desired GL driver by
455 manipulating variables such as `LD_LIBRARY_PATH`, `LIBGL_DRIVERS_DIR`, or
458 For example, on Linux:
460 ./scripts/retracediff.py \
461 --ref-env LD_LIBRARY_PATH=/path/to/reference/GL/implementation \
462 --retrace /path/to/glretrace \
463 --diff-prefix=/path/to/output/diffs \
468 python scripts\retracediff.py --retrace \path\to\glretrace.exe --ref-env TRACE_LIBGL=\path\to\reference\opengl32.dll application.trace
471 [![githalytics.com alpha](https://cruel-carlota.pagodabox.com/c1062ad633aa7a458e9d7520021307e4 "githalytics.com")](http://githalytics.com/apitrace/apitrace)