#include <GL/glut.h>
#include <stdlib.h>
#include <string>
#include <sstream>

#include <boost/chrono/chrono.hpp>

GLuint g_texId = 0;

void render(void);
void createEnvironment(void);
void resize(int,int);
void handleIdle(void);

int main(int argc,char **argv)
{
  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
  glutCreateWindow("SeeFront Demo");
  glutReshapeWindow(1920,1080);
  glutDisplayFunc(render);
  glutReshapeFunc(resize);
  glutIdleFunc(handleIdle);
  createEnvironment();
   
  glutMainLoop();
  
  return(0);
}

/*
 * Initialize OpenGL and SeeFront
 */
void createEnvironment(void)
{
  // OpenGL init
  glEnable(GL_DEPTH_TEST);
  glDisable(GL_LINE_SMOOTH);
  glDisable(GL_POINT_SMOOTH); 
  glDisable(GL_DITHER);
  glDisable(GL_CULL_FACE);
  
  glBindTexture(GL_TEXTURE_2D, g_texId);
  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA,  1920,  1080, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);	
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  glBindTexture(GL_TEXTURE_2D, 0);
}

/*
 * The render method.
 * Here the scene is rendered two times. One for the left eye and one for the right eye.
 * The rendered scene is copied into the textures and passed to the SeeFront object.
 */
void render(void)
{
  glClearColor(255, 0, 0, 255);
  glClear(GL_COLOR_BUFFER_BIT);
  
  unsigned char* buffer = new unsigned char[1920*1080*4];
  int mem;
  glReadPixels(0, 0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, &mem);
  boost::chrono::steady_clock::time_point tpStart = boost::chrono::steady_clock::now();
  glBindTexture(GL_TEXTURE_2D, g_texId);
  glTexSubImage2D(  GL_TEXTURE_2D, 0, 0, 0, 
                    1920, 
                    1080, 
					GL_RGBA,
                    GL_UNSIGNED_BYTE,
                    buffer);
  glBindTexture(GL_TEXTURE_2D, 0);
  glReadPixels(0, 0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, &mem);
  boost::chrono::steady_clock::time_point tpEnd = boost::chrono::steady_clock::now();
  boost::chrono::milliseconds dur = boost::chrono::duration_cast<boost::chrono::milliseconds>(tpEnd - tpStart);
  int msec = static_cast<int>(dur.count());    
  std::stringstream numberString;
  numberString << msec;  
  std::cout << numberString.str() << std::endl;
  delete buffer;
    
  glutSwapBuffers();
}


void handleIdle(void)
{
  glutPostRedisplay();
}


void resize(int w,int h)
{
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glViewport(0,0,(GLsizei)w,(GLsizei)h);
}