// ------------------------------------------------------------------------
  // This program is complementary material for the book:
  //
  // Frank Nielsen
  //
  // Visual Computing: Geometry, Graphics, and Vision
  //
  // ISBN: 1-58450-427-7
  //
  // Charles River Media, Inc.
  //
  //
  // All programs are available at www.charlesriver.com/visualcomputing/
  //
  // You may use this program for ACADEMIC and PERSONAL purposes ONLY. 
  //
  //
  // The use of this program in a commercial product requires EXPLICITLY
  // written permission from the author. The author is NOT responsible or 
  // liable for damage or loss that may be caused by the use of this program. 
  //
  // Copyright (c) 2005. Frank Nielsen. All rights reserved.
  // ------------------------------------------------------------------------
   
  // ------------------------------------------------------------------------
  // File: colorcube.cpp
  // 
  // Description: Rendering the RGB color cube in OpenGL(R)
  // ------------------------------------------------------------------------
  
  include <stdafx.h>
  
  include <glut.h>
  include <stdlib.h>
  include <stdio.h>
  include <math.h>
  
  typedef GLfloat Point3D[3];
  typedef GLfloat color[4];
  
  void display(void);
  void cube(void);
  void reshape(int,int);
  void keyboard(unsigned char,int,int);
  
  float angle=0.0;
  
  void display( void )
  {
     
          angle+=1.0;
          if (angle>360) angle-=360;
  
      glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  
          glPushMatrix();
          glRotatef(angle,1,0,1);
          cube();
          glPopMatrix();
          glutSwapBuffers();
   }
  
  void reshape(int w,int h)
  {
          glViewport(0,0,(GLsizei)w,(GLsizei)h);
          glMatrixMode(GL_PROJECTION);
          glLoadIdentity();
          gluPerspective(54,1.0,1.0,50.0);
          glMatrixMode(GL_MODELVIEW);
          glLoadIdentity();
          gluLookAt( 2.5,  2.5, 2.5, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0);
  }
  
  void cube(void)
  {
      Point3D vertices[8]={{-1.0, -1.0, -1.0},
                          {-1.0, -1.0,  1.0},
                          {-1.0,  1.0, -1.0},
                          {-1.0,  1.0,  1.0},
                          { 1.0, -1.0, -1.0},
                          { 1.0, -1.0,  1.0},
                          { 1.0,  1.0, -1.0},
                          { 1.0,  1.0,  1.0} };
  
          Point3D colors[8] = {{0.,0.,0.},
                                                  {0.,0.,1.},
                                                  {0.,1.,0.},
                                                  {0.,1.,1.},
                                                  {1.,0.,0.},
                                                  {1.,0.,1.},
                                                  {1.,1.,0.},
                                                  {1.,1.,1.} };
  
          // A cube is 6 quads defined by 8 vertices
      glBegin(GL_QUADS);
          
        glColor3fv(colors[1]);
        glVertex3fv(vertices[1]);
        glColor3fv(colors[5]);
        glVertex3fv(vertices[5]);
        glColor3fv(colors[7]);
        glVertex3fv(vertices[7]);
        glColor3fv(colors[3]);
        glVertex3fv(vertices[3]);
          
        glColor3fv(colors[7]);
        glVertex3fv(vertices[7]);
        glColor3fv(colors[6]);
        glVertex3fv(vertices[6]);
        glColor3fv(colors[2]);
        glVertex3fv(vertices[2]);
        glColor3fv(colors[3]);
        glVertex3fv(vertices[3]);
          
        glColor3fv(colors[2]);
        glVertex3fv(vertices[2]);
        glColor3fv(colors[6]);
        glVertex3fv(vertices[6]);
        glColor3fv(colors[4]);
        glVertex3fv(vertices[4]);
        glColor3fv(colors[0]);
        glVertex3fv(vertices[0]);
          
        glColor3fv(colors[5]);
        glVertex3fv(vertices[5]);
        glColor3fv(colors[4]);
        glVertex3fv(vertices[4]);
        glColor3fv(colors[6]);
        glVertex3fv(vertices[6]);
        glColor3fv(colors[7]);
        glVertex3fv(vertices[7]);
          
        glColor3fv(colors[4]);
        glVertex3fv(vertices[4]);
        glColor3fv(colors[5]);
        glVertex3fv(vertices[5]);
        glColor3fv(colors[1]);
        glVertex3fv(vertices[1]);
        glColor3fv(colors[0]);
        glVertex3fv(vertices[0]);
          
        glColor3fv(colors[0]);
        glVertex3fv(vertices[0]);
        glColor3fv(colors[1]);
        glVertex3fv(vertices[1]);
        glColor3fv(colors[3]);
        glVertex3fv(vertices[3]);
        glColor3fv(colors[2]);
        glVertex3fv(vertices[2]);
      glEnd();
   }
  
  void keyboard(unsigned char key, int x, int y)
  {
          glutPostRedisplay();
  }
  
  void idle()
  {
  glutPostRedisplay();        
  }
  
  void main(int argc, char** argv)
  {
          glutInit(&argc,argv);
          glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
          glutInitWindowSize(1024,1024);
          glutInitWindowPosition(70,70);
          glutCreateWindow("RGB Cube Color Space");
          glutDisplayFunc(display);
          glutReshapeFunc(reshape);
          glutKeyboardFunc(keyboard);
          glutIdleFunc(idle);
  
          glClearColor( 1,1,1, 0.0 );
          glEnable(GL_DEPTH_TEST); 
          glShadeModel(GL_SMOOTH);
  
          glutMainLoop();
  }