-The `LD_PRELOAD` mechanism should work with most applications. There are some
-applications, e.g., Unigine Heaven, which global function pointers with the
-same name as GL 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 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 into
-`LD_LIBRARY_PATH`:
+ apitrace dump --calls=CALLSET foo.trace
+ apitrace dump-images --calls=CALLSET foo.trace
+
+The call syntax is very flexible. Here are a few examples:
+
+ * `4` one call
+
+ * `0,2,4,5` set of calls
+
+ * `"0 2 4 5"` set of calls (commas are optional and can be replaced with whitespace)
+
+ * `0-100/2` calls 1, 3, 5, ..., 99
+
+ * `0-1000/draw` all draw calls between 0 and 1000
+
+ * `0-1000/fbo` all fbo changes between calls 0 and 1000
+
+ * `frame` all calls at end of frames
+
+ * `@foo.txt` read call numbers from `foo.txt`, using the same syntax as above
+
+
+
+Tracing manually
+----------------
+
+### Linux ###
+
+On 64 bits systems, you'll need to determine ether the application is 64 bits
+or 32 bits. This can be done by doing
+
+ file /path/to/application
+
+But beware of wrapper shell scripts -- what matters is the architecture of the
+main process.
+
+Run the GLX application you want to trace as
+
+ LD_PRELOAD=/path/to/apitrace/wrappers/glxtrace.so /path/to/application
+
+and it will generate a trace named `application.trace` in the current
+directory. You can specify the written trace filename by setting the
+`TRACE_FILE` environment variable before running.