#include <GL/glut.h>

/*=========================================================================*/

typedef struct
{
  float x;
  float y;
  float z;
  float r;
  float g;
  float b;
} point;

point p[8]={
    {-0.5,-0.5, 0.5,0.0,0.0,0.0},
    {-0.5, 0.5, 0.5,0.0,0.0,0.0},
    { 0.5, 0.5, 0.5,0.0,0.0,0.0},
    { 0.5,-0.5, 0.5,0.0,0.0,0.0},
    {-0.5,-0.5,-0.5,0.0,0.0,0.0},
    {-0.5, 0.5,-0.5,0.0,0.0,0.0},
    { 0.5, 0.5,-0.5,0.0,0.0,0.0},
    { 0.5,-0.5,-0.5,0.0,0.0,0.0}};
  
int f[6][4]={
  {0,1,2,3},
  {3,2,6,7},
  {4,5,6,7},
  {0,1,5,4},
  {1,5,6,2},
  {0,4,7,3}};

char presse;
int anglex,angley,x,y,xold,yold;
int width=500, heigth=500, deep=400;

/*=========================================================================*/

void texto(int x, int y, char *palabra);
void display();
void mouse(int bouton,int etat,int x,int y);
void mousemotion(int x,int y);

/*=========================================================================*/

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

  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
  glutInitWindowPosition(200,200);
  glutInitWindowSize(width,heigth);
  glutCreateWindow("cube");
  glOrtho(-(width/2), (width/2), -(heigth/2), (heigth/2), -deep, deep);

  glClearColor(1.0,1.0,1.0,0.0);
  glColor3f(1.0,1.0,1.0);
  glPointSize(2.0);
  glEnable(GL_DEPTH_TEST);

  glutDisplayFunc(display);
  glutMouseFunc(mouse);
  glutMotionFunc(mousemotion);


  glutMainLoop();
  return 0;
}

/*=========================================================================*/

void display()
{
  int i,j;

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  
  glLoadIdentity();
  
  
  /*--rotation of the mouse-*/
  /*------------------------*/
  
  glRotatef(-angley,1.0,0.0,0.0);
  glRotatef(-anglex,0.0,1.0,0.0);


  /*--drawing the cube--*/
  /*--------------------*/
  
  glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);

  for (i=0;i<6;i++)
    {
      glBegin(GL_POLYGON);
      for (j=0;j<4;j++)
	{
	  glColor3f(p[f[i][j]].r,p[f[i][j]].g,p[f[i][j]].b);
	  glVertex3f(p[f[i][j]].x,p[f[i][j]].y,p[f[i][j]].z);
	}
      glEnd();
    }
  glFlush();
  
   
  /*--displaying text ?--*/ 
  /*---------------------*/
  
  texto(-width/2+10,heigth/2-20,"blabla");


glutSwapBuffers();
}

/*=========================================================================*/

void texto(int x, int y, char *palabra) {

int i;
glColor3f(0,0,0);
glRasterPos2f(x, y);
for (i = 0; palabra[i]; i++)
   glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, palabra[i]);
}

/*=========================================================================*/

void mouse(int button, int state,int x,int y)
{

  if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN) 
  {
    presse = 1; 
    xold = x;
    yold=y;
  }

  if (button == GLUT_LEFT_BUTTON && state == GLUT_UP) 
    presse=0; 
}

/*=========================================================================*/

void mousemotion(int x,int y)
  {
    if (presse) 
    {
     
      anglex=anglex+(x-xold); 
      angley=angley+(y-yold);
      glutPostRedisplay(); 
    }
    
    xold=x; 
    yold=y;
  }