Re: [pygame] Sprite rotation

[Eric Burgess <eric@big-brain.org>]

Todd Smith wrote:

> how well does pygame (SDL) handle sprite rotation vs. pyopengl?
Not nearly as well.  In SDL, the rotation is done in software, versus 
pyopengl which uses your graphics hardware.  Also, SDL is tied to the 
notion of an axis-aligned rectangle (the image rotates, but it still has 
to be contained inside a rectangle with horizontal and vertical edges), 
so you have to concern yourself with resizing in order to avoid cropping 
the image.  Whereas with pyopengl, you just rotate the textured quad and 
that's it.

On the other hand, you have to do a bit more legwork setting up your 
game to use OpenGL, but not much more.  Since almost everyone has a 3D 
card these days, I would strongly recommend you take advantage of  it.  
The benefits in speed and graphical quality cannot be overstated--it's 
night and day.  Basically, you'll get all your graphics "for free"--I'm 
talking rotation, scaling, and alpha blending.  Your only bottleneck 
will be Python itself.  SDL starts to have problems just drawing the 
entire screen every frame...you have to mess with things like "dirty 
rectangle animation" to get decent performance, and you can't have 
things like smooth scrolling or other effects that change the entire 
screen every frame.  Your graphics card can handle 10,000 textured quads 
(sprites) with full effects, drawing 60 times a second, without even 
breaking a sweat.  Pyopengl lets you tap that power.

-Eric