### Linux ###
-On 64 bits systems, you'll need to determine ether the application is 64 bits
+On 64 bits systems, you'll need to determine whether the application is 64 bits
or 32 bits. This can be done by doing
file /path/to/application
The `LD_PRELOAD` mechanism should work with the majority applications. There
are some applications (e.g., Unigine Heaven, Android GPU emulator, etc.), that
-have global function pointers with the same name as GL entrypoints, living in a
+have global function pointers with the same name as OpenGL entrypoints, living in a
shared object that wasn't linked with `-Bsymbolic` flag, so relocations to
-those globals function pointers get overwritten with the address to our wrapper
+those global function pointers get overwritten with the address to our wrapper
library, and the application will segfault when trying to write to them. For
these applications it is possible to trace by using `glxtrace.so` as an
ordinary `libGL.so` and injecting it via `LD_LIBRARY_PATH`:
### Android ###
To trace standalone native OpenGL ES applications, use
-`LD_PRELOAD=/path/to/egltrace.so /path/to/application` like described in the
+`LD_PRELOAD=/path/to/egltrace.so /path/to/application` as described in the
previous section. To trace Java applications, refer to Dalvik.markdown.
### Mac OS X ###
* [`GL_GREMEDY_frame_terminator`](http://www.opengl.org/registry/specs/GREMEDY/frame_terminator.txt)
-**apitrace** will advertise and intercept these GL extensions regardless the GL
-implementation supports them or not. So all you have to do is to use these
-extensions when available, and you can be sure they will be available when
-tracing inside **apitrace**.
+**apitrace** will advertise and intercept these OpenGL extensions regardless
+of whether the OpenGL implementation supports them or not. So all you have
+to do is to use these extensions when available, and you can be sure they
+will be available when tracing inside **apitrace**.
For example, if you use [GLEW](http://glew.sourceforge.net/) to dynamically
-detect and use GL extensions, you could easily accomplish this by doing:
+detect and use OpenGL extensions, you could easily accomplish this by doing:
void foo() {
- if (GLEW_GREMEDY_string_marker) {
- glStringMarkerGREMEDY(0, __FUNCTION__ ": enter");
+ if (GLEW_KHR_debug) {
+ glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, 0, -1, __FUNCTION__);
}
...
- if (GLEW_GREMEDY_string_marker) {
- glStringMarkerGREMEDY(0, __FUNCTION__ ": leave");
+ if (GLEW_KHR_debug) {
+ glDebugMessageInsert(GL_DEBUG_SOURCE_APPLICATION, GL_DEBUG_TYPE_OTHER,
+ 0, GL_DEBUG_SEVERITY_MEDIUM, -1, "bla bla");
}
+ ...
+
+ if (GLEW_KHR_debug) {
+ glPopDebugGroup();
+ }
+
}
-This has the added advantage of working equally well with gDEBugger.
+This has the added advantage of working equally well with other OpenGL debugging tools.
Also, provided that the OpenGL implementation supports `GL_KHR_debug`, labels
defined via glObjectLabel() , and the labels of several objects (textures,
For OpenGL ES applications you can embed annotations in the trace file through the
+[`GL_KHR_debug`](http://www.khronos.org/registry/gles/extensions/KHR/debug.txt) or
[`GL_EXT_debug_marker`](http://www.khronos.org/registry/gles/extensions/EXT/EXT_debug_marker.txt)
-extension.
+extensions.
For Direct3D applications you can follow the standard procedure for
`ID3DUserDefinedAnnotation::SetMarker` for D3D11.1 applications.
-Dump GL state at a particular call
+Dump OpenGL state at a particular call
----------------------------------
-You can get a dump of the bound GL state at call 12345 by doing:
+You can get a dump of the bound OpenGL state at call 12345 by doing:
apitrace replay -D 12345 application.trace > 12345.json
-This is precisely the mechanism the GUI obtains its own state.
+This is precisely the mechanism the GUI uses to obtain its own state.
You can compare two state dumps by doing:
apitrace trim --exact --calls 0-12345 -o trimed.trace application.trace
If you need precise control over which calls to trim you can specify the
-individual call numbers a plaintext file, as described in the 'Call sets'
+individual call numbers in a plain text file, as described in the 'Call sets'
section above.
There is also experimental support for automatically trimming the calls
necessary for a given frame or call:
- apitrace trim --auto --calls=12345 -o trimed.trace application.trace
- apitrace trim --auto --frames=12345 -o trimed.trace application.trace
+ apitrace trim --auto --calls=12345 -o trimed.trace application.trace
+ apitrace trim --auto --frames=12345 -o trimed.trace application.trace
Profiling a trace
* `--ppd` record pixels drawn for each draw call.
-The results from this can then be read by hand or analysed with a script.
+The results from these can then be read by hand or analyzed with a script.
`scripts/profileshader.py` will read the profile results and format them into a
table which displays profiling results per shader.
commit responsible for a regression.
Below is an example of using tracecheck.py to bisect a regression in the
-Mesa-based Intel 965 driver. But the procedure could be applied to any GL
+Mesa-based Intel 965 driver. But the procedure could be applied to any OpenGL
driver hosted on a git repository.
First, create a build script, named build-script.sh, containing:
make "$@"
It is important that builds are both robust, and efficient. Due to broken
-dependency discovery in Mesa's makefile system, it was necessary invoke `make
+dependency discovery in Mesa's makefile system, it was necessary to invoke `make
clean` in every iteration step. `ccache` should be installed to avoid
recompiling unchanged source files.
failures.
The `--gl-renderer` option will also cause a commit to be skipped if the
-`GL_RENDERER` is unexpected (e.g., when a software renderer or another GL
-driver is unintentionally loaded due to missing symbol in the DRI driver, or
+`GL_RENDERER` is unexpected (e.g., when a software renderer or another OpenGL
+driver is unintentionally loaded due to a missing symbol in the DRI driver, or
another runtime fault).
generate snapshots for every draw call, using the `-S` option. That is, however,
very inefficient for big traces with many draw calls.
-A faster approach is to run both the bad and a good GL driver side-by-side.
-The latter can be either a previously known good build of the GL driver, or a
+A faster approach is to run both the bad and a good OpenGL driver side-by-side.
+The latter can be either a previously known good build of the OpenGL driver, or a
reference software renderer.
This can be achieved with retracediff.py script, which invokes glretrace with
-different environments, allowing to choose the desired GL driver by
+different environments, allowing to choose the desired OpenGL driver by
manipulating variables such as `LD_LIBRARY_PATH`, `LIBGL_DRIVERS_DIR`, or
`TRACE_LIBGL`.
For example, on Linux:
./scripts/retracediff.py \
- --ref-env LD_LIBRARY_PATH=/path/to/reference/GL/implementation \
+ --ref-env LD_LIBRARY_PATH=/path/to/reference/OpenGL/implementation \
--retrace /path/to/glretrace \
--diff-prefix=/path/to/output/diffs \
application.trace