4 **apitrace** consists of a set of tools to:
6 * trace OpenGL, D3D9, D3D8, D3D7, and DDRAW APIs calls to a file;
8 * retrace OpenGL calls from a file;
10 * visualize trace files, and inspect state.
20 Run the application you want to trace as
22 LD_PRELOAD=/path/to/glxtrace.so /path/to/application
24 and it will generate a trace named `application.trace` in the current
25 directory. You can specify the written trace filename by setting the
26 `TRACE_FILE` environment variable before running.
30 /path/to/tracedump application.trace | less -R
34 /path/to/glretrace application.trace
36 Pass the `-sb` option to use a single buffered visual. Pass `--help` to
37 glretrace for more options.
41 /path/to/qapitrace application.trace
44 The `LD_PRELOAD` mechanism should work with most applications. There are some
45 applications, e.g., Unigine Heaven, which global function pointers with the
46 same name as GL entrypoints, living in a shared object that wasn't linked with
47 `-Bsymbolic` flag, so relocations to those globals function pointers get
48 overwritten with the address to our wrapper library, and the application will
49 segfault when trying to write to them. For these applications it is possible
50 to trace by using `glxtrace.so` as an ordinary `libGL.so` and injecting into
53 ln -s glxtrace.so libGL.so
54 ln -s glxtrace.so libGL.so.1
55 ln -s glxtrace.so libGL.so.1.2
56 export LD_LIBRARY_PATH=/path/to/directory/where/glxtrace/is:$LD_LIBRARY_PATH
57 export TRACE_LIBGL=/path/to/real/libGL.so.1
60 See the `ld.so` man page for more information about `LD_PRELOAD` and
61 `LD_LIBRARY_PATH` environment flags.
68 Usage on Mac OS X is similar to Linux above, except for the tracing procedure,
71 DYLD_LIBRARY_PATH=/path/to/apitrace/wrappers /path/to/application
73 Note that although Mac OS X has an `LD_PRELOAD` equivalent,
74 `DYLD_INSERT_LIBRARIES`, it is mostly useless because it only works with
75 `DYLD_FORCE_FLAT_NAMESPACE=1` which breaks most applications. See the `dyld` man
76 page for more details about these environment flags.
82 * Copy `opengl32.dll`, `d3d8.dll`, or `d3d9.dll` from build/wrappers directory
83 to the directory with the application you want to trace.
85 * Run the application.
89 \path\to\tracedump application.trace
91 * Replay the trace with
93 \path\to\glretrace application.trace
96 Advanced command line usage
97 ===========================
100 Emitting annotations to the trace from GL applications
101 ------------------------------------------------------
103 You can emit string and frame annotations through the
104 [`GL_GREMEDY_string_marker`](http://www.opengl.org/registry/specs/GREMEDY/string_marker.txt)
106 [`GL_GREMEDY_frame_terminator`](http://www.opengl.org/registry/specs/GREMEDY/frame_terminator.txt)
109 *apitrace* will advertise and intercept these GL extensions independently of
110 the GL implementation. So all you have to do is to use these extensions when
113 For example, if you use [GLEW](http://glew.sourceforge.net/) to dynamically
114 detect and use GL extensions, you could easily accomplish this by doing:
118 if (GLEW_GREMEDY_string_marker) {
119 glStringMarkerGREMEDY(0, __FUNCTION__ ": enter");
124 if (GLEW_GREMEDY_string_marker) {
125 glStringMarkerGREMEDY(0, __FUNCTION__ ": leave");
130 This has the added advantage of working equally well with gDEBugger.
133 Dump GL state at a particular call
134 ----------------------------------
136 You can get a dump of the bound GL state at call 12345 by doing:
138 /path/to/glretrace -D 12345 application.trace > 12345.json
140 This is precisely the mechanism the GUI obtains its own state.
142 You can compare two state dumps with the jsondiff.py script:
144 ./scripts/jsondiff.py 12345.json 67890.json
147 Comparing two traces side by side
148 ---------------------------------
150 ./scripts/tracediff.sh trace1.trace trace2.trace
152 This works only on Unices, and it will truncate the traces due to performance
156 Recording a video with FFmpeg
157 -----------------------------
159 You can make a video of the output by doing
161 /path/to/glretrace -s - application.trace \
162 | ffmpeg -r 30 -f image2pipe -vcodec ppm -i pipe: -vcodec mpeg4 -y output.mp4
165 Advanced usage for OpenGL implementors
166 ======================================
168 There are several advanced usage examples meant for OpenGL implementors.
174 These are the steps to create a regression test-suite around apitrace:
178 * obtain reference snapshots, by doing:
180 mkdir /path/to/snapshots/
181 /path/to/glretrace -s /path/to/reference/snapshots/ application.trace
185 * prune the snapshots which are not interesting
187 * to do a regression test, do:
189 /path/to/glretrace -c /path/to/reference/snapshots/ application.trace
191 Alternatively, for a HTML summary, use the snapdiff script:
193 /path/to/glretrace -s /path/to/current/snapshots/ application.trace
194 ./scripts/snapdiff.py --output summary.html /path/to/reference/snapshots/ /path/to/current/snapshots/
197 Automated git-bisection
198 -----------------------
200 With tracecheck.py it is possible to automate git bisect and pinpoint the
201 commit responsible for a regression.
203 Below is an example of using tracecheck.py to bisect a regression in the
204 Mesa-based Intel 965 driver. But the procedure could be applied to any GL
205 driver hosted on a git repository.
207 First, create a build script, named build-script.sh, containing:
211 export PATH=/usr/lib/ccache:$PATH
214 ./autogen.sh --disable-egl --disable-gallium --disable-glut --disable-glu --disable-glw --with-dri-drivers=i965
218 It is important that builds are both robust, and efficient. Due to broken
219 dependency discovery in Mesa's makefile system, it was necessary invoke `make
220 clean` in every iteration step. `ccache` should be installed to avoid
221 recompiling unchanged source files.
226 export LIBGL_DEBUG=verbose
227 export LD_LIBRARY_PATH=$PWD/lib
228 export LIBGL_DRIVERS_DIR=$PWD/lib
230 6491e9593d5cbc5644eb02593a2f562447efdcbb 71acbb54f49089b03d3498b6f88c1681d3f649ac \
231 -- src/mesa/drivers/dri/intel src/mesa/drivers/dri/i965/
232 git bisect run /path/to/tracecheck.py \
233 --precision-threshold 8.0 \
234 --build /path/to/build-script.sh \
235 --gl-renderer '.*Mesa.*Intel.*' \
236 --retrace=/path/to/glretrace \
237 -c /path/to/reference/snapshots/ \
238 topogun-1.06-orc-84k.trace
240 The trace-check.py script will skip automatically when there are build
243 The `--gl-renderer` option will also cause a commit to be skipped if the
244 `GL_RENDERER` is unexpected (e.g., when a software renderer or another GL
245 driver is unintentionally loaded due to missing symbol in the DRI driver, or
246 another runtime fault).
249 Side by side retracing
250 ----------------------
252 In order to determine which draw call a regression first manifests one could
253 generate snapshots for every draw call, using the `-S` option. That is, however,
254 very inefficient for big traces with many draw calls.
256 A faster approach is to run both the bad and a good GL driver side-by-side.
257 The latter can be either a previously known good build of the GL driver, or a
258 reference software renderer.
260 This can be achieved with retracediff.py script, which invokes glretrace with
261 different environments, allowing to choose the desired GL driver by
262 manipulating variables such as `LD_LIBRARY_PATH` or `LIBGL_DRIVERS_DIR`.
266 ./scripts/retracediff.py \
267 --ref-env LD_LIBRARY_PATH=/path/to/reference/GL/implementation \
269 --diff-prefix=/path/to/output/diffs \
279 * [Official mailing list](http://lists.freedesktop.org/mailman/listinfo/apitrace)
281 * [Zack Rusin's blog introducing the GUI](http://zrusin.blogspot.com/2011/04/apitrace.html)
283 * [Jose's Fonseca blog introducing the tool](http://jrfonseca.blogspot.com/2008/07/tracing-d3d-applications.html)
291 * [Proxy DLL](http://www.mikoweb.eu/index.php?node=21)
293 * [Intercept Calls to DirectX with a Proxy DLL](http://www.codeguru.com/cpp/g-m/directx/directx8/article.php/c11453/)
295 * [Direct3D 9 API Interceptor](http://graphics.stanford.edu/~mdfisher/D3D9Interceptor.html)
299 * [Microsoft PIX](http://msdn.microsoft.com/en-us/library/ee417062.aspx)
301 * [D3DSpy](http://doc.51windows.net/Directx9_SDK/?url=/directx9_sdk/graphics/programmingguide/TutorialsAndSamplesAndToolsAndTips/Tools/D3DSpy.htm): the predecessor of PIX
303 * [AMD GPU PerfStudio](http://developer.amd.com/gpu/PerfStudio/pages/APITraceWindow.aspx)
311 * [BuGLe](http://www.opengl.org/sdk/tools/BuGLe/)
313 * [GLIntercept](http://code.google.com/p/glintercept/)
315 * [tracy](https://gitorious.org/tracy): OpenGL ES and OpenVG trace, retrace, and state inspection
319 * [gDEBugger](http://www.gremedy.com/products.php)
321 * [glslDevil](http://cumbia.informatik.uni-stuttgart.de/glsldevil/index.html)
323 * [AMD GPU PerfStudio](http://developer.amd.com/gpu/PerfStudio/pages/APITraceWindow.aspx)