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 * inspect OpenGL state at any call while retracing;
12 * visualize and edit trace files.
22 Run the application you want to trace as
24 LD_PRELOAD=/path/to/glxtrace.so /path/to/application
26 and it will generate a trace named `application.trace` in the current
27 directory. You can specify the written trace filename by setting the
28 `TRACE_FILE` environment variable before running.
32 /path/to/tracedump --color application.trace | less -R
36 /path/to/glretrace application.trace
38 Pass the `-sb` option to use a single buffered visual. Pass `--help` to
39 glretrace for more options.
43 /path/to/qapitrace application.trace
46 The `LD_PRELOAD` mechanism should work with most applications. There are some
47 applications, e.g., Unigine Heaven, which global function pointers with the
48 same name as GL entrypoints, living in a shared object that wasn't linked with
49 `-Bsymbolic` flag, so relocations to those globals function pointers get
50 overwritten with the address to our wrapper library, and the application will
51 segfault when trying to write to them. For these applications it is possible
52 to trace by using `glxtrace.so` as an ordinary `libGL.so` and injecting into
55 ln -s glxtrace.so libGL.so
56 ln -s glxtrace.so libGL.so.1
57 ln -s glxtrace.so libGL.so.1.2
58 export LD_LIBRARY_PATH=/path/to/directory/where/glxtrace/is:$LD_LIBRARY_PATH
59 export TRACE_LIBGL=/path/to/real/libGL.so.1
62 See the `ld.so` man page for more information about `LD_PRELOAD` and
63 `LD_LIBRARY_PATH` environment flags.
70 Usage on Mac OS X is similar to Linux above, except for the tracing procedure,
73 DYLD_LIBRARY_PATH=/path/to/apitrace/wrappers /path/to/application
75 Note that although Mac OS X has an `LD_PRELOAD` equivalent,
76 `DYLD_INSERT_LIBRARIES`, it is mostly useless because it only works with
77 `DYLD_FORCE_FLAT_NAMESPACE=1` which breaks most applications. See the `dyld` man
78 page for more details about these environment flags.
84 * Copy `opengl32.dll`, `d3d8.dll`, or `d3d9.dll` from build/wrappers directory
85 to the directory with the application you want to trace.
87 * Run the application.
91 \path\to\tracedump application.trace
93 * Replay the trace with
95 \path\to\glretrace application.trace
98 Advanced command line usage
99 ===========================
102 Emitting annotations to the trace from GL applications
103 ------------------------------------------------------
105 You can emit string and frame annotations through the
106 [`GL_GREMEDY_string_marker`](http://www.opengl.org/registry/specs/GREMEDY/string_marker.txt)
108 [`GL_GREMEDY_frame_terminator`](http://www.opengl.org/registry/specs/GREMEDY/frame_terminator.txt)
111 **apitrace** will advertise and intercept these GL extensions independently of
112 the GL implementation. So all you have to do is to use these extensions when
115 For example, if you use [GLEW](http://glew.sourceforge.net/) to dynamically
116 detect and use GL extensions, you could easily accomplish this by doing:
120 if (GLEW_GREMEDY_string_marker) {
121 glStringMarkerGREMEDY(0, __FUNCTION__ ": enter");
126 if (GLEW_GREMEDY_string_marker) {
127 glStringMarkerGREMEDY(0, __FUNCTION__ ": leave");
132 This has the added advantage of working equally well with gDEBugger.
135 Dump GL state at a particular call
136 ----------------------------------
138 You can get a dump of the bound GL state at call 12345 by doing:
140 /path/to/glretrace -D 12345 application.trace > 12345.json
142 This is precisely the mechanism the GUI obtains its own state.
144 You can compare two state dumps with the jsondiff.py script:
146 ./scripts/jsondiff.py 12345.json 67890.json
149 Comparing two traces side by side
150 ---------------------------------
152 ./scripts/tracediff.sh trace1.trace trace2.trace
154 This works only on Unices, and it will truncate the traces due to performance
158 Recording a video with FFmpeg
159 -----------------------------
161 You can make a video of the output by doing
163 /path/to/glretrace -s - application.trace \
164 | ffmpeg -r 30 -f image2pipe -vcodec ppm -i pipe: -vcodec mpeg4 -y output.mp4
167 Advanced usage for OpenGL implementors
168 ======================================
170 There are several advanced usage examples meant for OpenGL implementors.
176 These are the steps to create a regression test-suite around **apitrace**:
180 * obtain reference snapshots, by doing:
182 mkdir /path/to/snapshots/
183 /path/to/glretrace -s /path/to/reference/snapshots/ application.trace
187 * prune the snapshots which are not interesting
189 * to do a regression test, do:
191 /path/to/glretrace -c /path/to/reference/snapshots/ application.trace
193 Alternatively, for a HTML summary, use the snapdiff script:
195 /path/to/glretrace -s /path/to/current/snapshots/ application.trace
196 ./scripts/snapdiff.py --output summary.html /path/to/reference/snapshots/ /path/to/current/snapshots/
199 Automated git-bisection
200 -----------------------
202 With tracecheck.py it is possible to automate git bisect and pinpoint the
203 commit responsible for a regression.
205 Below is an example of using tracecheck.py to bisect a regression in the
206 Mesa-based Intel 965 driver. But the procedure could be applied to any GL
207 driver hosted on a git repository.
209 First, create a build script, named build-script.sh, containing:
213 export PATH=/usr/lib/ccache:$PATH
216 ./autogen.sh --disable-egl --disable-gallium --disable-glut --disable-glu --disable-glw --with-dri-drivers=i965
220 It is important that builds are both robust, and efficient. Due to broken
221 dependency discovery in Mesa's makefile system, it was necessary invoke `make
222 clean` in every iteration step. `ccache` should be installed to avoid
223 recompiling unchanged source files.
228 export LIBGL_DEBUG=verbose
229 export LD_LIBRARY_PATH=$PWD/lib
230 export LIBGL_DRIVERS_DIR=$PWD/lib
232 6491e9593d5cbc5644eb02593a2f562447efdcbb 71acbb54f49089b03d3498b6f88c1681d3f649ac \
233 -- src/mesa/drivers/dri/intel src/mesa/drivers/dri/i965/
234 git bisect run /path/to/tracecheck.py \
235 --precision-threshold 8.0 \
236 --build /path/to/build-script.sh \
237 --gl-renderer '.*Mesa.*Intel.*' \
238 --retrace=/path/to/glretrace \
239 -c /path/to/reference/snapshots/ \
240 topogun-1.06-orc-84k.trace
242 The trace-check.py script will skip automatically when there are build
245 The `--gl-renderer` option will also cause a commit to be skipped if the
246 `GL_RENDERER` is unexpected (e.g., when a software renderer or another GL
247 driver is unintentionally loaded due to missing symbol in the DRI driver, or
248 another runtime fault).
251 Side by side retracing
252 ----------------------
254 In order to determine which draw call a regression first manifests one could
255 generate snapshots for every draw call, using the `-S` option. That is, however,
256 very inefficient for big traces with many draw calls.
258 A faster approach is to run both the bad and a good GL driver side-by-side.
259 The latter can be either a previously known good build of the GL driver, or a
260 reference software renderer.
262 This can be achieved with retracediff.py script, which invokes glretrace with
263 different environments, allowing to choose the desired GL driver by
264 manipulating variables such as `LD_LIBRARY_PATH` or `LIBGL_DRIVERS_DIR`.
268 ./scripts/retracediff.py \
269 --ref-env LD_LIBRARY_PATH=/path/to/reference/GL/implementation \
271 --diff-prefix=/path/to/output/diffs \
281 * [Official mailing list](http://lists.freedesktop.org/mailman/listinfo/apitrace)
283 * [Zack Rusin's blog introducing the GUI](http://zrusin.blogspot.com/2011/04/apitrace.html)
285 * [Jose's Fonseca blog introducing the tool](http://jrfonseca.blogspot.com/2008/07/tracing-d3d-applications.html)
293 * [Proxy DLL](http://www.mikoweb.eu/index.php?node=21)
295 * [Intercept Calls to DirectX with a Proxy DLL](http://www.codeguru.com/cpp/g-m/directx/directx8/article.php/c11453/)
297 * [Direct3D 9 API Interceptor](http://graphics.stanford.edu/~mdfisher/D3D9Interceptor.html)
301 * [Microsoft PIX](http://msdn.microsoft.com/en-us/library/ee417062.aspx)
303 * [D3DSpy](http://doc.51windows.net/Directx9_SDK/?url=/directx9_sdk/graphics/programmingguide/TutorialsAndSamplesAndToolsAndTips/Tools/D3DSpy.htm): the predecessor of PIX
305 * [AMD GPU PerfStudio](http://developer.amd.com/gpu/PerfStudio/pages/APITraceWindow.aspx)
313 * [BuGLe](http://www.opengl.org/sdk/tools/BuGLe/)
315 * [GLIntercept](http://code.google.com/p/glintercept/)
317 * [tracy](https://gitorious.org/tracy): OpenGL ES and OpenVG trace, retrace, and state inspection
321 * [gDEBugger](http://www.gremedy.com/products.php)
323 * [glslDevil](http://cumbia.informatik.uni-stuttgart.de/glsldevil/index.html)
325 * [AMD GPU PerfStudio](http://developer.amd.com/gpu/PerfStudio/pages/APITraceWindow.aspx)