[Bug 25898] New: glEvalPoint within display list fails assertion in vbo_save_api.c

* [Bug 25898] New: glEvalPoint within display list fails assertion in vbo_save_api.c
@ 2010-01-05  6:14 bugzilla-daemon
  2010-01-05 17:15 ` [Bug 25898] " bugzilla-daemon
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: bugzilla-daemon @ 2010-01-05  6:14 UTC (permalink / raw)
  To: dri-devel

http://bugs.freedesktop.org/show_bug.cgi?id=25898

           Summary: glEvalPoint within display list fails assertion in
                    vbo_save_api.c
           Product: DRI
           Version: XOrg 6.7.0
          Platform: x86 (IA32)
        OS/Version: Linux (All)
            Status: NEW
          Severity: normal
          Priority: medium
         Component: libGL
        AssignedTo: dri-devel@lists.sourceforge.net
        ReportedBy: dnschneid@gmail.com

Created an attachment (id=32454)
 --> (http://bugs.freedesktop.org/attachment.cgi?id=32454)
Code demonstrating the assert failure.

If this is the wrong place to report this, please point me in the right
direction.

Recently I've been working on a game, and a bit of code that worked fine in
nvidia's proprietary libGL implementation fails an assertion in the mesa
version.

Basically, using glEvalPoint2 inside of a glBegin/glEnd block all inside a
glNewList/glEndList block seemingly has no effect (nothing is drawn when the
display list is called).  Putting a glVertex3f call in the same glBegin/End
block along with the calls to glEvalPoint causes a failed assertion:

vbo/vbo_save_api.c:503: _save_upgrade_vertex: Assertion `save->copied.nr == 0'
failed.

Using glVertex with no calls to glEvalPoint draws properly, and using
glEvalMesh instead of glBegin/glEvalPoint/glEnd works properly as well.

Again, all forms of the code work fine on nvidia's proprietary drivers.

Attached is a pretty short bit of C that demonstrates the error.  Comment out
the defines at the top of the page to use the glEvalPoint code that causes the
assert fail.  The code uses SDL to set up the window and rendering context.

With both defines enabled, glEvalMesh is used and a box should be drawn in the
center of the screen.
Disabling the WORK_PLEASE define will use glEvalPoint, which draws nothing
despite drawing the same box on nvidia's implementation.
Disabling both WORK_PLEASE and DONT_CRASH will insert a glVertex call that
causes the assert error.  Again, running on nvidia's proprietary implementation
draws a box.

I hope I've supplied sufficient detail; ask if you need any more information.

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