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.
15 Obtaining **apitrace**
16 ======================
18 To obtain apitrace either [download the latest
19 binaries](https://github.com/apitrace/apitrace/downloads) for your platform if
20 available, or follow the instructions in INSTALL.markdown to build it yourself.
21 On 64bits Linux and Windows platforms you'll need apitrace binaries that match
22 the architecture (32bits or 64bits) of the application being traced.
28 Run the application you want to trace as
30 apitrace trace --api API /path/to/application [args...]
32 and it will generate a trace named `application.trace` in the current
33 directory. You can specify the written trace filename by passing the
34 `--output` command line option.
36 Problems while tracing (e.g, if the application uses calls/parameters
37 unsupported by apitrace) will be reported via stderr output on Unices. On
38 Windows you'll need to run
39 [DebugView](http://technet.microsoft.com/en-us/sysinternals/bb896647) to view
42 Follow the "Tracing manually" instructions below if you cannot obtain a trace.
46 apitrace dump application.trace
48 Replay an OpenGL trace with
50 glretrace application.trace
52 Pass the `-sb` option to use a single buffered visual. Pass `--help` to
53 glretrace for more options.
61 qapitrace application.trace
63 You can also tell the GUI to go directly to a specific call
65 qapitrace application.trace 12345
68 Advanced command line usage
69 ===========================
75 Several tools take `CALLSET` arguments, e.g:
77 apitrace dump --calls CALLSET foo.trace
78 glretrace -S CALLSET foo.trace
80 The call syntax is very flexible. Here are a few examples:
84 * `1,2,4,5` set of calls
86 * `"1 2 4 5"` set of calls (commas are optional and can be replaced with whitespace)
88 * `1-100/2` calls 1, 3, 5, ..., 99
90 * `1-1000/draw` all draw calls between 1 and 1000
92 * `1-1000/fbo` all fbo changes between calls 1 and 1000
94 * `frame` all calls at end of frames
96 * `@foo.txt` read call numbers from `foo.txt`, using the same syntax as above
105 On 64 bits systems, you'll need to determine ether the application is 64 bits
106 or 32 bits. This can be done by doing
108 file /path/to/application
110 But beware of wrapper shell scripts -- what matters is the architecture of the
113 Run the application you want to trace as
115 LD_PRELOAD=/path/to/apitrace/wrappers/glxtrace.so /path/to/application
117 and it will generate a trace named `application.trace` in the current
118 directory. You can specify the written trace filename by setting the
119 `TRACE_FILE` environment variable before running.
121 The `LD_PRELOAD` mechanism should work with the majority applications. There
122 are some applications (e.g., Unigine Heaven, Android GPU emulator, etc.), that
123 have global function pointers with the same name as GL entrypoints, living in a
124 shared object that wasn't linked with `-Bsymbolic` flag, so relocations to
125 those globals function pointers get overwritten with the address to our wrapper
126 library, and the application will segfault when trying to write to them. For
127 these applications it is possible to trace by using `glxtrace.so` as an
128 ordinary `libGL.so` and injecting it via `LD_LIBRARY_PATH`:
130 ln -s glxtrace.so wrappers/libGL.so
131 ln -s glxtrace.so wrappers/libGL.so.1
132 ln -s glxtrace.so wrappers/libGL.so.1.2
133 export LD_LIBRARY_PATH=/path/to/apitrace/wrappers:$LD_LIBRARY_PATH
134 export TRACE_LIBGL=/path/to/real/libGL.so.1
137 If you are an application developer, you can avoid this either by linking with
138 `-Bsymbolic` flag, or by using some unique prefix for your function pointers.
140 See the `ld.so` man page for more information about `LD_PRELOAD` and
141 `LD_LIBRARY_PATH` environment flags.
143 To trace the application inside gdb, invoke gdb as:
145 gdb --ex 'set exec-wrapper env LD_PRELOAD=/path/to/glxtrace.so' --args /path/to/application
149 The following instructions should work at least for Android Ice Scream
152 For standalone applications the instructions above for Linux should
153 work. To trace applications started from within the Android VM process
154 (`app_process` aka zygote) you'll have to wrap this process and enable
155 tracing dynamically for the application to be traced.
157 - Wrapping the android main VM process:
159 In the Android root /init.rc add the `LD_PRELOAD` setting to zygote's
160 environment in the 'service zygote' section:
163 setenv LD_PRELOAD /data/egltrace.so
166 Note that ICS will overwrite the /init.rc during each boot with the
167 version in the recovery image. So you'll have to change the file in
168 your ICS source tree, rebuild and reflash the device.
169 Rebuilding/reflashing only the recovery image should be sufficient.
171 - Copy egltrace.so to /data
175 adb push /path/to/apitrace/build/wrappers/egltrace.so /data
177 - Adjust file permissions to store the trace file:
179 By default egltrace.so will store the trace in
180 `/data/app_process.trace`. For this to work for applications running
181 with a uid other than 0, you have to allow writes to the `/data`
182 directory on the device:
186 - Enable tracing for a specific process name:
188 To trace for example the Settings application:
190 setprop debug.apitrace.procname com.android.settings
192 In general this name will match what `ps` reports.
194 - Start the application:
196 If the application was already running, for example due to ICS's way
197 of pre-starting the apps, you might have to kill the application
202 Launch the application for example from the application menu.
206 Run the application you want to trace as
208 DYLD_LIBRARY_PATH=/path/to/apitrace/wrappers /path/to/application
210 Note that although Mac OS X has an `LD_PRELOAD` equivalent,
211 `DYLD_INSERT_LIBRARIES`, it is mostly useless because it only works with
212 `DYLD_FORCE_FLAT_NAMESPACE=1` which breaks most applications. See the `dyld` man
213 page for more details about these environment flags.
217 When tracing third-party applications, you can identify the target
218 application's main executable, either by:
220 * right clicking on the application's icon in the _Start Menu_, choose
221 _Properties_, and see the _Target_ field;
223 * or by starting the application, run Windows Task Manager (taskmgr.exe), right
224 click on the application name in the _Applications_ tab, choose _Go To Process_,
225 note the highlighted _Image Name_, and search it on `C:\Program Files` or
226 `C:\Program Files (x86)`.
228 On 64 bits Windows, you'll need to determine ether the application is a 64 bits
229 or 32 bits. 32 bits applications will have a `*32` suffix in the _Image Name_
230 column of the _Processes_ tab of _Windows Task Manager_ window.
232 Copy the appropriate `opengl32.dll`, `d3d8.dll`, or `d3d9.dll` from the
233 wrappers directory to the directory with the application you want to trace.
234 Then run the application as usual.
236 You can specify the written trace filename by setting the `TRACE_FILE`
237 environment variable before running.
240 Emitting annotations to the trace
241 ---------------------------------
243 From OpenGL applications you can embed annotations in the trace file through the
244 [`GL_GREMEDY_string_marker`](http://www.opengl.org/registry/specs/GREMEDY/string_marker.txt)
246 [`GL_GREMEDY_frame_terminator`](http://www.opengl.org/registry/specs/GREMEDY/frame_terminator.txt)
249 **apitrace** will advertise and intercept these GL extensions independently of
250 the GL implementation. So all you have to do is to use these extensions when
253 For example, if you use [GLEW](http://glew.sourceforge.net/) to dynamically
254 detect and use GL extensions, you could easily accomplish this by doing:
258 if (GLEW_GREMEDY_string_marker) {
259 glStringMarkerGREMEDY(0, __FUNCTION__ ": enter");
264 if (GLEW_GREMEDY_string_marker) {
265 glStringMarkerGREMEDY(0, __FUNCTION__ ": leave");
270 This has the added advantage of working equally well with gDEBugger.
273 From OpenGL ES applications you can embed annotations in the trace file through the
274 [`GL_EXT_debug_marker`](http://www.khronos.org/registry/gles/extensions/EXT/EXT_debug_marker.txt)
278 For Direct3D applications you can follow the same procedure used for
279 [instrumenting an application for PIX](http://technet.microsoft.com/en-us/query/ee417250)
282 Dump GL state at a particular call
283 ----------------------------------
285 You can get a dump of the bound GL state at call 12345 by doing:
287 glretrace -D 12345 application.trace > 12345.json
289 This is precisely the mechanism the GUI obtains its own state.
291 You can compare two state dumps by doing:
293 apitrace diff-state 12345.json 67890.json
296 Comparing two traces side by side
297 ---------------------------------
299 apitrace diff trace1.trace trace2.trace
301 This works only on Unices, and it will truncate the traces due to performance
305 Recording a video with FFmpeg
306 -----------------------------
308 You can make a video of the output by doing
310 glretrace -s - application.trace \
311 | ffmpeg -r 30 -f image2pipe -vcodec ppm -i pipe: -vcodec mpeg4 -y output.mp4
317 You can make a smaller trace by doing:
319 apitrace trim --callset 100-1000 -o trimed.trace applicated.trace
321 If you need precise control over which calls to trim you can specify the
322 individual call numbers a plaintext file, as described in the 'Call sets'
329 You can perform gpu and cpu profiling with the command line options:
331 * `-pgpu` record gpu times for frames and draw calls.
333 * `-pcpu` record cpu times for frames and draw calls.
335 * `-ppd` record pixels drawn for each draw call.
337 The results from this can then be read by hand or analysed with a script.
339 `scripts/profileshader.py` will read the profile results and format them into a
340 table which displays profiling results per shader.
342 For example, to record all profiling data and utilise the per shader script:
344 ./glretrace -pgpu -pcpu -ppd foo.trace | ./scripts/profileshader.py
347 Advanced usage for OpenGL implementors
348 ======================================
350 There are several advanced usage examples meant for OpenGL implementors.
356 These are the steps to create a regression test-suite around **apitrace**:
360 * obtain reference snapshots, by doing on a reference system:
362 mkdir /path/to/reference/snapshots/
363 glretrace -s /path/to/reference/snapshots/ application.trace
365 * prune the snapshots which are not interesting
367 * to do a regression test, do:
369 glretrace -c /path/to/reference/snapshots/ application.trace
371 Alternatively, for a HTML summary, use `apitrace diff-images`:
373 glretrace -s /path/to/test/snapshots/ application.trace
374 apitrace diff-images --output summary.html /path/to/reference/snapshots/ /path/to/test/snapshots/
377 Automated git-bisection
378 -----------------------
380 With tracecheck.py it is possible to automate git bisect and pinpoint the
381 commit responsible for a regression.
383 Below is an example of using tracecheck.py to bisect a regression in the
384 Mesa-based Intel 965 driver. But the procedure could be applied to any GL
385 driver hosted on a git repository.
387 First, create a build script, named build-script.sh, containing:
391 export PATH=/usr/lib/ccache:$PATH
394 ./autogen.sh --disable-egl --disable-gallium --disable-glut --disable-glu --disable-glw --with-dri-drivers=i965
398 It is important that builds are both robust, and efficient. Due to broken
399 dependency discovery in Mesa's makefile system, it was necessary invoke `make
400 clean` in every iteration step. `ccache` should be installed to avoid
401 recompiling unchanged source files.
406 export LIBGL_DEBUG=verbose
407 export LD_LIBRARY_PATH=$PWD/lib
408 export LIBGL_DRIVERS_DIR=$PWD/lib
410 6491e9593d5cbc5644eb02593a2f562447efdcbb 71acbb54f49089b03d3498b6f88c1681d3f649ac \
411 -- src/mesa/drivers/dri/intel src/mesa/drivers/dri/i965/
412 git bisect run /path/to/tracecheck.py \
413 --precision-threshold 8.0 \
414 --build /path/to/build-script.sh \
415 --gl-renderer '.*Mesa.*Intel.*' \
416 --retrace=/path/to/glretrace \
417 -c /path/to/reference/snapshots/ \
418 topogun-1.06-orc-84k.trace
420 The trace-check.py script will skip automatically when there are build
423 The `--gl-renderer` option will also cause a commit to be skipped if the
424 `GL_RENDERER` is unexpected (e.g., when a software renderer or another GL
425 driver is unintentionally loaded due to missing symbol in the DRI driver, or
426 another runtime fault).
429 Side by side retracing
430 ----------------------
432 In order to determine which draw call a regression first manifests one could
433 generate snapshots for every draw call, using the `-S` option. That is, however,
434 very inefficient for big traces with many draw calls.
436 A faster approach is to run both the bad and a good GL driver side-by-side.
437 The latter can be either a previously known good build of the GL driver, or a
438 reference software renderer.
440 This can be achieved with retracediff.py script, which invokes glretrace with
441 different environments, allowing to choose the desired GL driver by
442 manipulating variables such as `LD_LIBRARY_PATH`, `LIBGL_DRIVERS_DIR`, or
445 For example, on Linux:
447 ./scripts/retracediff.py \
448 --ref-env LD_LIBRARY_PATH=/path/to/reference/GL/implementation \
449 --retrace /path/to/glretrace \
450 --diff-prefix=/path/to/output/diffs \
455 python scripts\retracediff.py --retrace \path\to\glretrace.exe --ref-env TRACE_LIBGL=\path\to\reference\opengl32.dll application.trace
463 * [Official mailing list](http://lists.freedesktop.org/mailman/listinfo/apitrace)
465 * [Zack Rusin's blog introducing the GUI](http://zrusin.blogspot.com/2011/04/apitrace.html)
467 * [Jose's Fonseca blog introducing the tool](http://jrfonseca.blogspot.com/2008/07/tracing-d3d-applications.html)
475 * [Proxy DLL](http://www.mikoweb.eu/index.php?node=21)
477 * [Intercept Calls to DirectX with a Proxy DLL](http://www.codeguru.com/cpp/g-m/directx/directx8/article.php/c11453/)
479 * [Direct3D 9 API Interceptor](http://graphics.stanford.edu/~mdfisher/D3D9Interceptor.html)
483 * [Microsoft PIX](http://msdn.microsoft.com/en-us/library/ee417062.aspx)
485 * [D3DSpy](http://doc.51windows.net/Directx9_SDK/?url=/directx9_sdk/graphics/programmingguide/TutorialsAndSamplesAndToolsAndTips/Tools/D3DSpy.htm): the predecessor of PIX
487 * [NVIDIA PerfKit](http://developer.nvidia.com/nvidia-perfkit)
489 * [AMD GPU PerfStudio](http://developer.amd.com/gpu/PerfStudio/pages/APITraceWindow.aspx)
491 * [Intel Graphics Performance Analyzers](http://www.intel.com/software/gpa/)
499 * [BuGLe](http://www.opengl.org/sdk/tools/BuGLe/)
501 * [GLIntercept](http://code.google.com/p/glintercept/)
503 * [tracy](https://gitorious.org/tracy): OpenGL ES and OpenVG trace, retrace, and state inspection
505 * [WebGL-Inspector](http://benvanik.github.com/WebGL-Inspector/)
509 * [AMD CodeXL](http://developer.amd.com/tools/hc/CodeXL/Pages/default.aspx)
511 * [AMD GPU PerfStudio](http://developer.amd.com/gpu/PerfStudio/pages/APITraceWindow.aspx)
513 * [gDEBugger](http://www.gremedy.com/products.php) and [AMD gDEBugger](http://developer.amd.com/tools/gDEBugger/Pages/default.aspx)
515 * [glslDevil](http://cumbia.informatik.uni-stuttgart.de/glsldevil/index.html)