Re: [pygame] Lousy FPS

[Jan Pobrislo <ccx@xxxxxxxxxxxxxx>]

Dne Tuesday 12 September 2006 21:23 Kris Schnee napsal(a):
> I was messing with a Pygame/OpenGL version of my tile graphics engine,
> and am alarmed by a framerate issue.
> This is the OpenGL version, which looks this bad because of hastily
> drawn textures, full lighting, etc.:
> http://kschnee.xepher.net/pics/3dthing.jpg
> This is the older version using isometric tiles:
> http://kschnee.xepher.net/pics/shiningsea060630-0.jpg
>
> In each case the underlying world data is the same. My thinking in doing
> the GL version was that I wouldn't have to draw those awkward diagonal
> tiles, and that I'd be able to rotate to any angle. I tested it just now
> and got 12 FPS (using a time.sleep(.05) call so the max would be 20).
> OK, I said, the tradeoff is that the Pygame isometric version would be
> faster than the OpenGL.
>
> So I tested the isometric version. 6 FPS, even with the logo and
> interface turned off. Not good. How can my pasting tiles on a 2D surface
> be slower than calling an OpenGL list of lists of 3D cube-drawing
> instructions?
>
> I'll post the complete "Pearl3D" code if you want to see it.
>
> Kris

Actually, if you want OpenGL version to do isometric rendering, you'll need to 
tweak the transformation matrix a bit. I didn't do it for a while, but you 
need something like this:

in GL_PROJECTION matrix setup glOrtho view
in GL_MODELVIEW glLoad something like this:
| 1 0 0 0 |
| 0 1 0 0 |
| 0 x 1 0 |
| 0 0 0 1 |
where x is ratio by which Z axis distances (height in world) are translated to 
Y axis (up/down on screen), you'll probably use 0.5

you might also be able to use glMultMatrix on GL_PROJECTION instead of glLoad 
on GL_MODELVIEW, to have bigger freedom manipulating with modelview matrix