SDL2 sample

main.cpp

//SDL2 flashing random color example
//Should work on iOS/Android/Mac/Windows/Linux

#include <SDL.h>
#include <SDL_opengl.h>

#include <stdlib.h> //rand()

static bool quitting = false;
static float r = 0.0f;
static SDL_Window *window = NULL;
static SDL_GLContext gl_context;


    void render() {

        SDL_GL_MakeCurrent(window, gl_context);

            r = static_cast <float> (rand()) / static_cast <float> (RAND_MAX);

            glClearColor( r, 0.4f, 0.1f, 1.0f );
            glClear( GL_COLOR_BUFFER_BIT );

        SDL_GL_SwapWindow(window);

    } //render


    int SDLCALL watch(void *userdata, SDL_Event* event) {

        if (event->type == SDL_APP_WILLENTERBACKGROUND) {
            quitting = true;
        }

        return 1;
    }

int main(int argc, char *argv[]) {


    if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_EVENTS) != 0) {
        SDL_Log("Failed to initialize SDL: %s", SDL_GetError());
        return 1;
    }

    window = SDL_CreateWindow("title", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 512, 512, SDL_WINDOW_OPENGL);

    gl_context = SDL_GL_CreateContext(window);

    SDL_AddEventWatch(watch, NULL);


    while(!quitting) {

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

        render();
        SDL_Delay(2);

    }

    SDL_DelEventWatch(watch, NULL);
    SDL_GL_DeleteContext(gl_context);
    SDL_DestroyWindow(window);
    SDL_Quit();

    exit(0);

} //main