On Tue, Dec 22, 2009 at 4:51 PM, Stefan Dösinger stefan@codeweavers.com wrote:
We had a discussion in wine-devel a few days ago about which GL usage is better. The red book also agrees with the GL wiki, but the GL 3.0 spec uses the confusing language the extension used.
In my performance testing there is no difference, which suggests that this is a rather academic issue, unless you happen to run a game that is exactly hitting your card's bus transfer limits and/or video memory limits, but not the CPU and GPU ALU performance limits.
I'm not convinced the code should be changed back. All docs mention to use DYNAMIC_DRAW. On some implementations there might be a difference. I don't see a reason to change it. Did you get a response on the question you submitted to opengl.org? From what I understood the main difference between STREAM_DRAW and DYNAMIC_DRAW is that in case of dynamic, system memory which can be accessed using DMA is used and else this guarantee isn't given. I would keep it at the value which is correct as indicated by all documentation. If you want to change it, tests should be carried out on different drivers and GPUs OR wait for the feedback from opengl.org/
Roderick