/*
      SDL2 Render API & OpenGL Combined

clang++ -std=c++11 -stdlib=libc++ -I/SSystem/Library/Frameworks/OpenGL.framework/Headers -I/usr/local/include/SDL2 -L/usr/local/lib -L/System/Library/Frameworks/OpenGL.framework -l sdl2 -framework opengl gl.cpp -o gl

Source: https://forums.libsdl.org/viewtopic.php?t=9440&sid=087dc25c12164d8521dd92ad6cf5d430
*/

#include <iostream>

#include <OpenGL/OpenGL.h>
#include <OpenGL/glu.h>

#include <SDL.h>

int main ( int argc, char** argv )
{
  SDL_Init ( SDL_INIT_VIDEO );

  // SDL_SetHint( SDL_HINT_VIDEO_MAC_FULLSCREEN_SPACES, "0" );

  SDL_Window* win = SDL_CreateWindow ( "test", 20, 20, 640, 480,
                                       SDL_WINDOW_OPENGL );
  SDL_GLContext glcontext = SDL_GL_CreateContext ( win );
  int oglIdx = -1;
  int nRD = SDL_GetNumRenderDrivers();
  for ( int i = 0; i < nRD; i++ )
  {
    SDL_RendererInfo info;
    if ( !SDL_GetRenderDriverInfo ( i, &info ) )
    {
      if ( !strcmp ( info.name, "opengl" ) )
      {
        oglIdx = i;
      }
    }
  }
  SDL_Renderer* renderer = SDL_CreateRenderer ( win, oglIdx,
                           SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC );
  SDL_GL_SetAttribute ( SDL_GL_DOUBLEBUFFER, 1 );
  glMatrixMode ( GL_PROJECTION | GL_MODELVIEW );
  glLoadIdentity();
  glOrtho ( -320, 320, 240, -240, 0, 1 );

  SDL_Event event;
  bool quit = false;
  bool fs = false;

  int x;
  int y;
  while ( !quit )
  {
    while ( SDL_PollEvent ( &event ) )
    {
      switch( event.type )
      {
        case SDL_QUIT: quit = true; break;

        case SDL_MOUSEBUTTONDOWN:
        {

          break;
        }
        case SDL_MOUSEMOTION:
        {
          x = event.motion.xrel;
          y = event.motion.yrel;
          std::cout << x << "\n";
          std::cout << y << "\n";
          break;
        }

        case SDL_KEYDOWN:
        {
          switch( event.key.keysym.sym )
          {
            case SDLK_ESCAPE:
            case SDLK_q: quit = true; break;

            case SDLK_f:
            {
              if( fs )
              {
                SDL_SetWindowFullscreen(win, 0);
                fs = false;
              }
              else
              {
                SDL_SetWindowFullscreen(win, SDL_WINDOW_FULLSCREEN_DESKTOP);
                fs = true;
              }
              break;
            }
          }
          break;
        }
      }

      glClearColor ( 0, 0, 0, 0 );
      glClear ( GL_COLOR_BUFFER_BIT );

      glRotatef ( 0.6, 0.0, 0.0, 1.0 );
      float x = 30.0, y = 30.0;

      glBegin ( GL_TRIANGLES );
      glColor3f ( 1.0, 1.0, 0.0 );
      glVertex2f ( x, y + 90.0 );

      glColor3f ( 1.0, 1.0, 0.0 );
      glVertex2f ( x + 90.0, y - 90.0 );

      glColor3f ( 1.0, 1.0, 1.0 );
      glVertex2f ( x - 90.0, y - 90.0 );

      glEnd();

      glPushMatrix();
      glLoadIdentity();
      glOrtho ( -320, 320, 240, -240, 0, 1 );
      glColor4f ( 255, 0, 0, 255 );

      SDL_SetRenderDrawColor ( renderer, 255, 0, 0, 255 );
      SDL_RenderDrawLine ( renderer, -320 + 0, -240 + 0, -320 + 100, -240 + 100 );

      glPopMatrix();

      SDL_RenderPresent ( renderer );
      SDL_Delay ( 10 );
    }
  }
  SDL_DestroyRenderer ( renderer );
  SDL_Quit();
  return 0;
}