[Mesa-dev] [PATCH 1/3] vbo: move vbo_draw_method into vbo_context.h

[Mathias Fröhlich]

Hi,

On Tuesday, May 08, 2012 01:12:51 Marek Olšák wrote:
> AFAIK the "Enabled" flags aren't very useful in determining the final
> number of vertex elements, because if an array is not enabled, the
> corresponding zero-stride "current" attrib is used instead. So the
> quick check would depend solely on vertex shader inputs. If your
> definition of "enabled array" is that it's just used by the vertex
> shader, then sorry for stating the obvious. ;)

May be not in the current code, but the _mesa_array_object_get_enabled_* 
bitmask tricks show how you can immediatly (with an O(1) bitmask operation - 
no O(33) loop) see even for different aliasing situations which arrays are 
enabled.
If you combine this by bit operations with the enabled shader inputs bitmask 
you can update the array state incrementally using ffs based loops only doing 
work on very few of the 33 client arrays.

Sigh, I hope to find some time to distil the proof of concept stuff into 
something usable ...

Greetings

Mathias