[SDL] SDL "Sprite" handling...

[Gordon Henderson]

Hi,

I'm looking to add some sprite handling to my little project - ie. a small 
bitmap image that I can move over (on top of) the screen according to 
program control.

I just want to make sure I'm not being too naive and not missing something 
obvious!

Looking at this:

http://gamedevgeek.com/tutorials/moving-sprites-with-sdl/

it seems straightforward, however that program re-draws the entire screen 
every frame. I want my sprites to "float" on-top of any background without 
having to re-draw the background, so .... For each sprite, If I

   blit the screen rectangle (same x,y,size as sprite) into a temp. buffer,
   blit the sprite to the screen,
   update/flip,
   blit the screen temp. buffer back to the screen

lather rise, repeat with new sprite position and so on. Each sprite 
needing a Surface to hold the sprite and another the same size to hold the 
copy of the background.

I'm fairly sure that will work, but it will be doing a lot of memory moves 
(even if rather small, say 20x20 pixels) and as long as I draw then /erase 
them in the same order (or erase in reverse order) then the background 
ought to stay untouched and sprites can happily move on-top of each other. 
Although its will be doing a lot less memory moves than the example in 
that website above!

I have seen SDL-Layer, but in its absence is the above OK, or am I 
missing a trick?

Cheers,

Gordon