On 12/16/2011 11:28 AM, Mathias Fröhlich wrote:
Brian,
On Thursday, December 15, 2011 22:36:24 you wrote:
I found the problem. It's this chunk in vbo_context.c:
[...]
For fixed function, the point is to simply place the per-vertex
material attributes in the generic attribute arrays. There are 12
such material attributes. So there's four slots left over.
Yep, and these map with the old scheme to often used attributes like the
vertex position.
I still don't get what the purpose of the special mapping of the last
four/five elements is all about. Can you explain that?
Thanks to your hints I believe that I found the underlying problem:
If you look at the resulting bitmasks for the enabled vertex program inputs in
isosurf by commenting out the printf in _mesa_set_varying_vp_inputs you will
see surprising results with the old numbering. The current checked in
numbering looks much more plausible.
It turns out that this wrong varying_vp_inputs mask sets the _NEW_ARRAY bit
through _mesa_set_varying_vp_inputs. That in turn cares for some (by now in my
debug session untracked) state updates. This helps in the end for isosurf.
If the varying_vp_inputs mask looks plausible the _NEW_ARRAY bit is not set
and isosurf fails.
This also explaines that only draw paths going through vbo_exec_array.c are
affected, since the imm variants in vbo_exec_{safe,draw} always set the
_NEW_ARRAY bit on any draw.
Yeah, I see how the incorrect varying_inputs values was causing
_NEW_ARRAY to get set, thus hiding the problem. The solution looks
correct, but I'm a little worried about performance, as is mentioned
in the comment.
Marek, made that change back in March. Maybe he can take a look at
this too.
So for me this change
diff --git a/src/mesa/vbo/vbo_exec_array.c b/src/mesa/vbo/vbo_exec_array.c
index a6e41e9..a2851c4 100644
--- a/src/mesa/vbo/vbo_exec_array.c
+++ b/src/mesa/vbo/vbo_exec_array.c
@@ -446,7 +446,7 @@ recalculate_input_bindings(struct gl_context *ctx)
* to revalidate vertex arrays. Not marking the state as dirty also
* improves performance (quite significantly in some apps).
*/
- if (!ctx->VertexProgram._MaintainTnlProgram)
+ /* if (!ctx->VertexProgram._MaintainTnlProgram) */
ctx->NewState |= _NEW_ARRAY;
break;
makes isosurf work reliable.
I will prepare a patch for that.
Greetings
Mathias
-Brian
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