SDL cpu usage

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Original post by rip-off [q]you'll find that your program will get most of the cpu time anyway...

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Original post by Feidias Quote: Original post by rip-off [q]you'll find that your program will get most of the cpu time anyway... But only when it is active and doing something. I want to drop the cpu usage when the program is not active. SDL doesn't do that by itself. I was testing with Photoshop to see how it works. After starting it the cpu usage is down to nothing. When you draw something, it will shoot to 100% and then lower back to 4% or something like that. SDL works different way. It's always 100%, no matter if it's active or not. And it's slowing down other programs.

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Original post by rip-off remember, it is your prgram that uses 100% of the cpu, not SDL.

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there is an SDL_Event, that tells you when this occurs. use that and some testing to see how long your program should SDL_Delay for...

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Original post by nprz If you have nothing new to draw to the screen, don't draw anything (and you can also add in a millisecond delay). Make a bool that is set to true if you do anything on the screen, click, click+mouse-move, key press. After drawing you can set the bool so it won't draw again until something else is done.

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Original post by Feidias Incorrect. You can write a test program with no other events than SDL_QUIT and see what happens. SDL_PollEvent will take 100% of cpu time, not my program.

SDL_Event Game::get_useful_event(){    SDL_Event event;    while(1){        if( !SDL_WaitEvent( &event ) )            continue;        update_screen();        if(event.type == SDL_QUIT)            end_game();        switch( event.type ){            case SDL_KEYDOWN:                switch( event.key.keysym.sym ){                    case SDLK_ESCAPE:                        end_game();                        break;                    // handle other input                    default:                        break;                }            case SDL_KEYUP:            case SDL_MOUSEBUTTONDOWN:            case SDL_MOUSEBUTTONUP:            case SDL_MOUSEMOTION:                return event;                break;            default:                continue;                break;        }// end switch( event.type )    }}

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Original post by rip-off EDIT: sorry if i sound very defensive, but youre putting this as a "SDL problem", whereas sdl is not to blame.

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Original post by Feidias Quote: Original post by rip-off EDIT: sorry if i sound very defensive, but youre putting this as a "SDL problem", whereas sdl is not to blame. Well, it's quite easy to think that it's a problem related to SDL, because I was just using the example code found practically in all tutorials. I had no idea that PollEvent was using all cpu time and why it does that. However the source example above seems to handle the situation without any subtle SDL_Delay with "magic" number. Thanks!