CODEWITHSUNDEEP
c++sdl-3
Simtech Innovation
Simtech Innovation

Reputation: 1

Why does my SDL3 C++ app display very low fps but my frame count is very high

I am using gettimeofday() function to calculate how long my code takes. I am also counting how many frames have been displayed. The count shows that my code has done 6408 frames in 10 seconds - but on the screen I am only seeing about 8 fps. Here is my code:

SDL_AppResult SDL_AppIterate(void *appstate)
{
    struct timeval stop, start;
     
    SDL_RenderClear(renderer);

    gettimeofday(&start, NULL);

    for( int i=0; i<1000; i++)
    {
        float x = rand() % 3000;
        float y = rand() % 2000;

        SDL_FRect srcRect = {200,200,100,100};
        SDL_FRect destRect = {x,y,100,100};

        SDL_RenderTexture(renderer, fontTex, &srcRect, &destRect);

    }

    gettimeofday(&stop, NULL);
    long cpu_time_used1 = (stop.tv_sec - start.tv_sec) * 1000000 + stop.tv_usec - start.tv_usec;


    gettimeofday(&start, NULL);

    SDL_RenderPresent(renderer);

    gettimeofday(&stop, NULL);
    long cpu_time_used2 = (stop.tv_sec - start.tv_sec) * 1000000 + stop.tv_usec - start.tv_usec;


    char output[100];
    snprintf(output, 50, "%d,   %lu,   %lu", count++, cpu_time_used1, cpu_time_used2);
    SDL_Log(output);

    return SDL_APP_CONTINUE;
}

The output of my code looks like this (at the end):

6406, 83, 1198

6407, 101, 1184

6408, 106, 1186

These timing numbers seem very low - is it possible that SDL3 is that quick? And why are I only seeing very low fps?

Upvotes: -1

Views: 63

Answers (0)

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