gltrace: Emit fake glViewport/glScissor calls the first time a context is bound.

[apitrace] / BUGS.markdown

diff --git a/BUGS.markdown b/BUGS.markdown
index 989379b540e9a5bc2c26111034ad58eb62eff952..0c963f11a37befaf0b6be61eba437f67ad4df54b 100644 (file)
--- a/BUGS.markdown
+++ b/BUGS.markdown
@@ -50,12 +50,29 @@ Tracing
   There is no way to distinguish the fake calls from those actually
   made by the application yet.
 
+* Huge traces will be generated for applications that make extensive use of
+  immediate mode drawing (ie., glBegin/glEnd), use vertex/element arrays in
+  user memory, or generate a lot of dynamic vertex data per frame.
+
+  However, this should not be a problem for modern OpenGL applications that
+  make an efficient use of VBOs and vertex shaders.
+
 * On MacOSX, the internal OpenGL calls done by GLU are not traced yet.
 
 
 Retracing
 ---------
 
+* Replaying can take substantially more CPU due to the overhead of reading the
+  trace file from disk.
+
+  However, the overhead should not be significant for modern 3D applications
+  that do efficient use of VBOs and vertex shaders.  The communication between
+  CPU to GPU can easily be a bottleneck on the powerful discrete GPUs of
+  nowadays, and trace overhead tend to be propotional so it is not a
+  coincidence that applications that are optimized for modern GPUs will also be
+  traced and replayed efficiently.
+
 * glretrace needs to infer window sizes from glViewport calls, because calls
   that create/resize windows happen outside of OpenGL and are not traced.
   Therefore window will be missing if the application relies on the default
@@ -120,9 +137,8 @@ Please attach long logs to https://gist.github.com/ and paste the URL into the
 issue description.
 
 For big attachments, such as traces, please upload it temporarily to a web
-server you control, or use a file upload service such as
-http://www.megaupload.com/ or http://dropbox.com/ and paste the URL into the
-issue description.
+server you control, or use a file upload service such as http://dropbox.com/
+and paste the URL into the issue description.
 
 Trace files are only slightly compressed (for performance reasons).  You can
 further reduce their size when attaching/uploading by compressing with