CODEWITHSUNDEEP
c++sdlsdl-2
synaodev
synaodev

Reputation: 21

My SDL2 apps have a severe delay ONLY after the first keyboard input

In all of my C++ SDL2 programs, there is a severe delay following the first keyboard input. After that first input, everything else seems to work just fine.

It happens even in the most bare-bones programs.

Is there something that I'm doing wrong, or is this a bug?

If it's relevant, my operating system is macOS.

And here is some code with the problem:

#include <SDL2/SDL.h>
#include <iostream> 
#include <stdexcept>

int main(int argc, char *argv[])
{
    if(SDL_Init(SDL_INIT_VIDEO) != 0)
    {
        throw std::runtime_error("SDL failed to initialize.\n");
    }

    SDL_Window *window = SDL_CreateWindow("App", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 480, NULL);

    bool done = false;

    unsigned start_time = 0;
    unsigned tick_time = 0;

    while(!done)
    {
        SDL_Event event;

        while(SDL_PollEvent(&event))
        {
            if(event.type == SDL_QUIT)
            {
                done = true;
            }
        }

        start_time = tick_time;

        tick_time = SDL_GetTicks();

        const unsigned delta_time = tick_time - start_time;

        if(delta_time != 0)
        {
            if((1000 / delta_time) < 30)
            {
                std::cout << 1000 / delta_time << '\n';
            }
        }
    }

    SDL_DestroyWindow(window);

    SDL_Quit();

    return 0;
}

Upvotes: 2

Views: 255

Answers (1)

Licensed Slacker
Licensed Slacker

Reputation: 388

I think you should set start_time with SDL_GetTicks() rather than set it to zero before entering to the main loop. SDL_GetTicks() returns time since SDL_Init() and it might be something else than zero at this point.

Upvotes: 1

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