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](http://apitrace.github.com/#download) 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 To trace applications started from within the Android VM process
158 (`app_process` aka zygote) you'll have to wrap this process and enable
159 tracing dynamically for the application to be traced.
161 - Wrapping the android main VM process:
163 In the Android root /init.rc add the `LD_PRELOAD` setting to zygote's
164 environment in the 'service zygote' section:
167 setenv LD_PRELOAD /data/egltrace.so
170 Note that ICS will overwrite the /init.rc during each boot with the
171 version in the recovery image. So you'll have to change the file in
172 your ICS source tree, rebuild and reflash the device.
173 Rebuilding/reflashing only the recovery image should be sufficient.
175 - Copy egltrace.so to /data
179 adb push /path/to/apitrace/build/wrappers/egltrace.so /data
181 - Adjust file permissions to store the trace file:
183 By default egltrace.so will store the trace in
184 `/data/app_process.trace`. For this to work for applications running
185 with a uid other than 0, you have to allow writes to the `/data`
186 directory on the device:
190 - Enable tracing for a specific process name:
192 To trace for example the Settings application:
194 setprop debug.apitrace.procname com.android.settings
196 In general this name will match what `ps` reports.
198 - Start the application:
200 If the application was already running, for example due to ICS's way
201 of pre-starting the apps, you might have to kill the application
206 Launch the application for example from the application menu.
208 To trace standalone applications do:
210 adb push /path/to/apitrace/build/wrappers/egltrace.so /data
213 # LD_PRELOAD=/data/egltrace.so test-opengl-gl2_basic
214 adb pull /data/local/tmp/test-opengl-gl2_basic.trace
215 eglretrace test-opengl-gl2_basic.trace
219 Run the application you want to trace as
221 DYLD_LIBRARY_PATH=/path/to/apitrace/wrappers /path/to/application
223 Note that although Mac OS X has an `LD_PRELOAD` equivalent,
224 `DYLD_INSERT_LIBRARIES`, it is mostly useless because it only works with
225 `DYLD_FORCE_FLAT_NAMESPACE=1` which breaks most applications. See the `dyld` man
226 page for more details about these environment flags.
230 When tracing third-party applications, you can identify the target
231 application's main executable, either by:
233 * right clicking on the application's icon in the _Start Menu_, choose
234 _Properties_, and see the _Target_ field;
236 * or by starting the application, run Windows Task Manager (taskmgr.exe), right
237 click on the application name in the _Applications_ tab, choose _Go To Process_,
238 note the highlighted _Image Name_, and search it on `C:\Program Files` or
239 `C:\Program Files (x86)`.
241 On 64 bits Windows, you'll need to determine ether the application is a 64 bits
242 or 32 bits. 32 bits applications will have a `*32` suffix in the _Image Name_
243 column of the _Processes_ tab of _Windows Task Manager_ window.
245 Copy the appropriate `opengl32.dll`, `d3d8.dll`, or `d3d9.dll` from the
246 wrappers directory to the directory with the application you want to trace.
247 Then run the application as usual.
249 You can specify the written trace filename by setting the `TRACE_FILE`
250 environment variable before running.
252 For D3D10 and higher you really must use `apitrace trace -a DXGI ...`. This is
253 because D3D10-11 API span many DLLs which depend on each other, and once a DLL
254 with a given name is loaded Windows will reuse it for LoadLibrary calls of the
255 same name, causing internal calls to be traced erroneously. `apitrace trace`
256 solves this issue by injecting a DLL `dxgitrace.dll` and patching all modules
257 to hook only the APIs of interest.
260 Emitting annotations to the trace
261 ---------------------------------
263 From OpenGL applications you can embed annotations in the trace file through the
264 [`GL_GREMEDY_string_marker`](http://www.opengl.org/registry/specs/GREMEDY/string_marker.txt)
266 [`GL_GREMEDY_frame_terminator`](http://www.opengl.org/registry/specs/GREMEDY/frame_terminator.txt)
269 **apitrace** will advertise and intercept these GL extensions independently of
270 the GL implementation. So all you have to do is to use these extensions when
273 For example, if you use [GLEW](http://glew.sourceforge.net/) to dynamically
274 detect and use GL extensions, you could easily accomplish this by doing:
278 if (GLEW_GREMEDY_string_marker) {
279 glStringMarkerGREMEDY(0, __FUNCTION__ ": enter");
284 if (GLEW_GREMEDY_string_marker) {
285 glStringMarkerGREMEDY(0, __FUNCTION__ ": leave");
290 This has the added advantage of working equally well with gDEBugger.
293 From OpenGL ES applications you can embed annotations in the trace file through the
294 [`GL_EXT_debug_marker`](http://www.khronos.org/registry/gles/extensions/EXT/EXT_debug_marker.txt)
298 For Direct3D applications you can follow the standard procedure for
299 [adding user defined events to Visual Studio Graphics Debugger / PIX](http://msdn.microsoft.com/en-us/library/vstudio/hh873200.aspx):
301 - `D3DPERF_BeginEvent`, `D3DPERF_EndEvent`, and `D3DPERF_SetMarker` for D3D9 applications.
303 - `ID3DUserDefinedAnnotation::BeginEvent`,
304 `ID3DUserDefinedAnnotation::EndEvent`, and
305 `ID3DUserDefinedAnnotation::SetMarker` for D3D11.1 applications.
308 Dump GL state at a particular call
309 ----------------------------------
311 You can get a dump of the bound GL state at call 12345 by doing:
313 apitrace retrace -D 12345 application.trace > 12345.json
315 This is precisely the mechanism the GUI obtains its own state.
317 You can compare two state dumps by doing:
319 apitrace diff-state 12345.json 67890.json
322 Comparing two traces side by side
323 ---------------------------------
325 apitrace diff trace1.trace trace2.trace
327 This works only on Unices, and it will truncate the traces due to performance
331 Recording a video with FFmpeg
332 -----------------------------
334 You can make a video of the output by doing
336 apitrace dump-images -o - application.trace \
337 | ffmpeg -r 30 -f image2pipe -vcodec ppm -i pipe: -vcodec mpeg4 -y output.mp4
343 You can make a smaller trace by doing:
345 apitrace trim --callset 100-1000 -o trimed.trace applicated.trace
347 If you need precise control over which calls to trim you can specify the
348 individual call numbers a plaintext file, as described in the 'Call sets'
355 You can perform gpu and cpu profiling with the command line options:
357 * `--pgpu` record gpu times for frames and draw calls.
359 * `--pcpu` record cpu times for frames and draw calls.
361 * `--ppd` record pixels drawn for each draw call.
363 The results from this can then be read by hand or analysed with a script.
365 `scripts/profileshader.py` will read the profile results and format them into a
366 table which displays profiling results per shader.
368 For example, to record all profiling data and utilise the per shader script:
370 apitrace retrace --pgpu --pcpu --ppd foo.trace | ./scripts/profileshader.py
373 Advanced usage for OpenGL implementors
374 ======================================
376 There are several advanced usage examples meant for OpenGL implementors.
382 These are the steps to create a regression test-suite around **apitrace**:
386 * obtain reference snapshots, by doing on a reference system:
388 mkdir /path/to/reference/snapshots/
389 apitrace dump-images -o /path/to/reference/snapshots/ application.trace
391 * prune the snapshots which are not interesting
393 * to do a regression test, use `apitrace diff-images`:
395 apitrace dump-images -o /path/to/test/snapshots/ application.trace
396 apitrace diff-images --output summary.html /path/to/reference/snapshots/ /path/to/test/snapshots/
399 Automated git-bisection
400 -----------------------
402 With tracecheck.py it is possible to automate git bisect and pinpoint the
403 commit responsible for a regression.
405 Below is an example of using tracecheck.py to bisect a regression in the
406 Mesa-based Intel 965 driver. But the procedure could be applied to any GL
407 driver hosted on a git repository.
409 First, create a build script, named build-script.sh, containing:
413 export PATH=/usr/lib/ccache:$PATH
416 ./autogen.sh --disable-egl --disable-gallium --disable-glut --disable-glu --disable-glw --with-dri-drivers=i965
420 It is important that builds are both robust, and efficient. Due to broken
421 dependency discovery in Mesa's makefile system, it was necessary invoke `make
422 clean` in every iteration step. `ccache` should be installed to avoid
423 recompiling unchanged source files.
428 export LIBGL_DEBUG=verbose
429 export LD_LIBRARY_PATH=$PWD/lib
430 export LIBGL_DRIVERS_DIR=$PWD/lib
432 6491e9593d5cbc5644eb02593a2f562447efdcbb 71acbb54f49089b03d3498b6f88c1681d3f649ac \
433 -- src/mesa/drivers/dri/intel src/mesa/drivers/dri/i965/
434 git bisect run /path/to/tracecheck.py \
435 --precision-threshold 8.0 \
436 --build /path/to/build-script.sh \
437 --gl-renderer '.*Mesa.*Intel.*' \
438 --retrace=/path/to/glretrace \
439 -c /path/to/reference/snapshots/ \
440 topogun-1.06-orc-84k.trace
442 The trace-check.py script will skip automatically when there are build
445 The `--gl-renderer` option will also cause a commit to be skipped if the
446 `GL_RENDERER` is unexpected (e.g., when a software renderer or another GL
447 driver is unintentionally loaded due to missing symbol in the DRI driver, or
448 another runtime fault).
451 Side by side retracing
452 ----------------------
454 In order to determine which draw call a regression first manifests one could
455 generate snapshots for every draw call, using the `-S` option. That is, however,
456 very inefficient for big traces with many draw calls.
458 A faster approach is to run both the bad and a good GL driver side-by-side.
459 The latter can be either a previously known good build of the GL driver, or a
460 reference software renderer.
462 This can be achieved with retracediff.py script, which invokes glretrace with
463 different environments, allowing to choose the desired GL driver by
464 manipulating variables such as `LD_LIBRARY_PATH`, `LIBGL_DRIVERS_DIR`, or
467 For example, on Linux:
469 ./scripts/retracediff.py \
470 --ref-env LD_LIBRARY_PATH=/path/to/reference/GL/implementation \
471 --retrace /path/to/glretrace \
472 --diff-prefix=/path/to/output/diffs \
477 python scripts\retracediff.py --retrace \path\to\glretrace.exe --ref-env TRACE_LIBGL=\path\to\reference\opengl32.dll application.trace
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