///////////////////////////////////
// square.cpp
//
// OpenGL program to draw a square.
// 
// Sumanta Guha.
///////////////////////////////////

#include <GL/glew.h>
#include <GL/freeglut.h>
#include <GL/glext.h>
#include <iostream>

using namespace std;

// global variables for callbacks
//  Color_Mode controls how the square will be colored.
int Color_Mode;
GLfloat Color[4][3];

// Drawing routine.
void drawScene(void)
{
   glClear(GL_COLOR_BUFFER_BIT);

   if (Color_Mode == 0) {
       glColor3f(0.0, 0.0, 0.0);
   }

   // Draw a polygon with specified vertices.
   glBegin(GL_POLYGON);
      if (Color_Mode == 1) {
          glColor3fv(Color[0]);
      }
      glVertex3f(20.0, 20.0, 0.0);
      if (Color_Mode == 1) {
          glColor3fv(Color[1]);
      }
      glVertex3f(80.0, 20.0, 0.0);
      if (Color_Mode == 1) {
          glColor3fv(Color[2]);
      }
      glVertex3f(80.0, 80.0, 0.0);
      if (Color_Mode == 1) {
          glColor3fv(Color[3]);
      }
      glVertex3f(20.0, 80.0, 0.0);
   glEnd();

   glFlush(); 
}


void reset(void) {
    int i,j;

    // color mode setting
    Color_Mode = 0;

    // color setting
    for(j=0;j<4;j++) {
        for(i=0;i<3;i++) {
            Color[j][i] = 0.0;
	}
    }

    // red green blue by default
    for(i=0;i<3;i++) {
        Color[i][i] = 1;
    }

    // something for color 4
    Color[3][0] = 1.0;
    Color[3][2] = 1.0;

    return;

}

// Initialization routine.
void setup(void) 
{
   reset();
   glClearColor(1.0, 1.0, 1.0, 0.0); 
}



// OpenGL window reshape routine.
void resize(int w, int h)
{
   glViewport(0, 0, w, h);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   glOrtho(0.0, 100.0, 0.0, 100.0, -1.0, 1.0);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
}

void RotateColor(GLfloat color[3]) {
    float tmp;

    tmp = color[0];
    color[0] = color[1];
    color[1] = color[2];
    color[2] = tmp;

    return;
}

// Keyboard input processing routine.
void keyInput(unsigned char key, int x, int y)
{
   bool redisplay = true;
   int i;


   switch(key) 
   {
      case 'c':
          Color_Mode ++;
	  if (Color_Mode > 1) {
	      Color_Mode = 0;
	  }
	  cout << "Color_Mode is now " << Color_Mode << endl;
	  break;
      case 'C':
          for(i=0;i<4;i++) {
              RotateColor(Color[i]);
	  }
          break;
      case 'q':
      case 'Q':
      case 27:
         redisplay = false;
         exit(0);
         break;
      default:
         redisplay = false;
         cout << "Keypress " << key << " does not have an assigned action " 
	      << endl;
         break;
   }

   if (redisplay) {
      glutPostRedisplay();
   }
}

void idle() {
    static int count =0;

    if (count == 10000000 )  {
       cout << "Idle Function, nothing to report" << endl;
       count = 0;
    } else {
        count++;
    }
    return;
}

void mouse(int button, int state, int x, int y) {
     cout << "Button Press, it was " ;
     switch(button) {
        case GLUT_LEFT_BUTTON: 
	     cout << "the left ";
	     break;
	case GLUT_MIDDLE_BUTTON:
	     cout << "the middle ";
	     break;
	case GLUT_RIGHT_BUTTON:
	     cout << "the right ";
	     break;
	default: 
	     cout << "an unknown ";
     }
     cout << "button" << endl;

     cout << "It was ";
     switch(state) {
         case GLUT_DOWN:
	     cout << "pressed ";
	     break;
	 case GLUT_UP:
	     cout << "released ";
	     break;
     }
     cout << endl; 
     cout << " At position (" << x << ", " << y << ") " << endl;

}

void motion(int x, int y)  {
    cout << "Motion x=" << x << ", y = " << y << endl;
    return;
}

void passiveMotion(int x, int y)  {
    cout << "Passive motion x=" << x << ", y = " << y << endl;
    return;
}

void wheel(int wheel, int direction, int x, int y) {
     cout << "Mouse Wheel number " << wheel << endl;
     cout << "\twas spun " << direction << " by x= " << x  << ", y = " << y 
          << endl;
 
     return;
}

// Main routine.
int main(int argc, char **argv) 
{
   glutInit(&argc, argv);

   glutInitContextVersion(3,0);
   glutInitContextProfile(GLUT_CORE_PROFILE);
   //glutInitContextProfile(GLUT_COMPATIBILITY_PROFILE);

   glutInitDisplayMode(GLUT_SINGLE | GLUT_RGBA); 
   glutInitWindowSize(500, 500);
   glutInitWindowPosition(100, 100); 
   glutCreateWindow("square.cpp");
   glutDisplayFunc(drawScene); 
   glutReshapeFunc(resize);  
   glutIdleFunc(idle);
   glutMotionFunc(motion);
   glutMouseFunc(mouse);
   glutPassiveMotionFunc(passiveMotion);
   glutMouseWheelFunc(wheel);
   glutKeyboardFunc(keyInput);

   glewExperimental = GL_TRUE;
   glewInit();

   setup(); 
   
   glutMainLoop(); 
}