[Qt5-feedback] Front-to-back rendering pass of QML Scenegraph

[gunnar.sletta at nokia.com]

On May 13, 2011, at 4:35 PM, ext Tom Cooksey wrote:

> Years ago, it was discussed that Qt could to a front-to-back rendering pass of all opaque items in the QML scene graph and then follow that up with a back-to-front pass of all the (potentially) transparent and discard'able pixels. Is that still the plan? Such a front-to-back pass would yield significant performance improvements on ARM Mali GPUs and probably other GPUs too.

Hi Tom,

The scene graph default renderer will sort opaque elements by material to minimize state changes followed by drawing transparent elements back to front. There is also an option to sort the opaque elements front-to-back rather and disregard the material state changes. 

Right not you can enable the front-to-back rendering by passing --opaque-front-to-back on the command line or implement a scene graph backend plugin to enable the option explicitly for your setup. The --opaque-front-to-back option will probably go away when we get closer to a final release.

Feedback on which is better on various hardware would be interesting feedback indeed. 

-
Gunnar