Optimize SDL blitting routine

@thread

done other tests.

Software mode Windowed: 9 fps
Software mode Full screen: 10 fps

Hardware mode Full Screen: 40 - 61 FPS
Hardware mode Full Screen Double Buffer: 30 FPS

there is a glitch in the game, tho. Don't seems related to compositing acceleration. It's seems a sync problem.
Moreover, using the HW Accelleration, the VRAM (at least in the little sam440 ep) is soon saturated.

@AmigaBlitter

That seems to be in line with my alphablit benchmark. Typically HW alpha blitting is 5-10 times faster than SW.

As I have now GCC5 too, perhaps I can take a look at the remaining problems, excluding the VRAM limitation :) You have to use smaller bitmaps to fight that one.

@Capehill

The game doesn't freeze anymore. The problem was caused by the scaler functions accessing the surface with getpixel and putpixel without locking the surfaces.

I'll remove completely the scaler function, it's not needed.
I will send you the modified version. Please try to remove the sync problems.

@AmigaBlitter

Flickering is probably caused by overdraw. Each frame background is drawn and then game elements. Double-buffering should solve it. Can you try?

EDIT: after briefly reading AnimationState.cpp, which creates Background objects with new - where Backgrounds are deleted? If nowhere, they leak VRAM.

@Capehill

I will check. As said the code is not mine, i'm just exending some parts.

thank you for info

I already checked using DOUBLEBUF (see post above), but the flickering still and the FPS drops from 60 to 30.

" after briefly reading AnimationState.cpp, which creates Background objects with new - where Backgrounds are deleted? If nowhere, they leak VRAM."

Didn't noticed that. Will look into it

@AmigaBlitter

There was about 1 megabyte of VRAM left when I ran Arkanoid. On serial output there was a warning from SDL that CompositeTags() returned 3. I suspect some of the bitmaps are swapped out of VRAM and CompositeTags() falled back to SW.

I propose you fix the memory leaks and try to reduce used VRAM, then retest. If there is still flickering going on but megabytes of VRAM left, I will debug the SDL side.