Software blitting performance SFML/SDL

[CharlieOne]

Hi all,

I hope I'm not beating a dead horse here :wink: , but unfortunately I didn't find what I'm looking for by using my google-fu, so hopefully you guys can help me:

Did anyone of you benchmark of SFML's software rendering speed (i.e. simply blitting a 2d surface/pixel array to screen) vs. SDL on an average desktop/laptop system?

The thread at http://www.sfml-dev.org/forum/viewtopic.php?t=43&start=0&postdays=0&postorder=asc&highlight= is about rendering sprites and text, not exactly what I'm looking for (think ray tracer here).

Thanks for your help,

C1

[Laurent]

I think there's absolutely no problem to display one screen-size surface with very decent framerate, either with SFML or SDL. Or with Allegro, Clanlib, GDI, etc.

Your raytracing algorithms will probably be much slower.

[Groogy]

You want to know benchmarks for blitting of 2D arrays of pixels? Well drawing a Sprite is equivalent if not exactly that.

[Disch]

You want to know benchmarks for blitting of 2D arrays of pixels? Well drawing a Sprite is equivalent if not exactly that.

Not really.  Rendering sprites is hardware->hardware.  I think OP was talking about software->hardware which is going to be considerably slower.

[Groogy]

You want to know benchmarks for blitting of 2D arrays of pixels? Well drawing a Sprite is equivalent if not exactly that.

Not really.  Rendering sprites is hardware->hardware.  I think OP was talking about software->hardware which is going to be considerably slower.

Aaah.... does SFML even support that?

[Laurent]

Aaah.... does SFML even support that?

Yes, using Image::LoadFromPixels (or UpdatePixels in SFML 2).

[Groogy]

Aaah.... does SFML even support that?

Yes, using Image::LoadFromPixels (or UpdatePixels in SFML 2).

Wait so, The sf::Image::LoadFromPixels will make Image behave kinda like a SDL_Surface with the SDL_SWSURFACE flag set? Did not know that, you learn something new every day ^^

[CharlieOne]

Hi all,

thanks for your input!

Yes, I meant software->hardware rendering, if that's the way to put it. Sorry if that wasn't made clear; english is not my native language.

And of course the vast majority of runtime is spent in the actual algorithms with ray tracers in general, but I wanted to look in every direction regarding possible optimizations. But if you think the differences will be negligible, then perhaps I shouldn't spend too much time on this matter - and migrating the backend (my current implementation is using SDL) would certainly be some effort, too.

Thanks again,

C1

[Laurent]

Wait so, The sf::Image::LoadFromPixels will make Image behave kinda like a SDL_Surface with the SDL_SWSURFACE flag set?

I don't think you can compare them this way. LoadFromPixels just copies the pixels from system RAM to a texture in video memory, then you need a sprite to display this texture.