Simple SDL2 init and usage.

main.cpp

//
//  main.cpp
//
//  Created by Fabio Reis on 16/12/2019.
//

#include <SDL2/SDL.h>

int main(int, char**) {
    if (SDL_Init(SDL_INIT_VIDEO) != 0) {
        SDL_Log("Unable to initialize SDL: %s", SDL_GetError());
        return 1;
    }
    
    SDL_Window *window = SDL_CreateWindow("Hello World", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 800, 600, SDL_WINDOW_SHOWN);

    SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, 0);
    
    bool quit = false;
    while(!quit) {
        SDL_Event event;
        while (SDL_PollEvent(&event)) {
            if(event.type == SDL_QUIT) {
                quit = true;
            }
        }

        uint32_t ticks = SDL_GetTicks();
        float rate = 1000.f;
        float shift = sinf(ticks / rate);
        float phase = cosf(ticks * 2 / rate);
        float angle = cosf(ticks * 3 / rate);
        SDL_SetRenderDrawColor(renderer, fabsf(shift * 255.f), fabsf(phase * 255.f), fabsf(angle * 255.f), 255);
        SDL_RenderClear(renderer);
        SDL_RenderPresent(renderer);
        SDL_Delay(16);
    }
    
    SDL_Quit();
    return 0;
}