What price OpenGL?

In the old days I could never get OpenGL code up to the same kind of performance that Direct 3D normally has for me.  That's all changed now - with OpenGL 3.x or higher I can quite easily hit and occasionally exceed those framerates on id1 timedemos without even trying very hard (and this is on AMD gfx too so you can be certain that it's not a driver-related advantage).  Direct 3D still pulls ahead in more complex scenes - the Marcher scene gets me 550-odd FPS with OpenGL but currently well over 900 with Direct3D on the same hardware and at the same resolution and other settings.  But all the same - it's promising stuff (and I haven't touched MDL optimization in OpenGL code much so there's potentially more to be had) and takes no time at all (a coupla days really) to complete a basic port.

There is a lot to be said for OpenGL at this level.  It's actually a very very nice API to use, you no longer come out of a coding session feeling like you've just wrestled with a Bison, and it's productive and fast to get things up and running.  You can actually focus on getting stuff done rather than having to spend 50-odd percent of your time trying to beat the API into shape.

There are still some nasties left in it though (bind-to-modify is the main one and lack of any decent connection to the windowing system API is another key failing), but on the whole they counterbalance the nasties that also exist in comparable levels of Direct 3D.  I mocked and scorned a little when the GL 3 and 4 specs were released and I need to take that back now - I was wrong.  These were good things and gave OpenGL a much needed shove in the right direction.

Last year's release of Rage - despite the shenanigans that happened in the first few months - helped a lot to knock drivers into shape too.

This all means that an OpenGL port of DirectQ is something that could now happen.  On the whole I think I'll personally be sticking with Direct 3D for various reasons - it's like a comfortable old pair of boots by now, and the Intel situation still needs to be considered - but the potential is there and it would run at a similar speed.

That's all quite exciting and I would never have predicted it happening back when I started.