/* cs4451_a2.c */
/* 
PLEASE PUT YOUR NAME HERE
*/


#include <math.h>
#include <stdio.h>
#include <stdlib.h>

#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>

#define VPD_MIN     200
#define VPD_DEFAULT 800
#define VPD_MAX     1024

#define MENU_SLOWER 1
#define MENU_FASTER 2
#define MENU_STOP_RUN 3

#define TWOPI (2.0 * M_PI)

/* --------------------------------------------- */

GLint wid, /* GLUT window id               */
      vpd = VPD_DEFAULT; /* (square) viewport dimensions */

/* --------------------------------------------- */

GLuint sceneID;      /* display list ID */

/* --------------------------------------------- */

GLfloat angle1 = 0;  /* angles used in animation */
GLfloat angle2 = 0;
GLfloat dangle1 = 0.57;
GLfloat dangle2 = 0.71;

GLint animate = 1;   /* animate or not? */

/* --------------------------------------------- */

GLvoid init_lightsource ( GLvoid )
{
  GLfloat light_ambient[] = { .1, .1, .1, 1.0 };
  GLfloat light_diffuse[] = { .9, .9, .9, 1.0 };
  GLfloat light_specular[] = { 0, 0, 0, 1.0 };
  GLfloat light_position[] = { 2.0, 2.0, 2.0, 0.0 };

  glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
  glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
  glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
  glLightfv(GL_LIGHT0, GL_POSITION, light_position);
  glLightf(GL_LIGHT0,GL_CONSTANT_ATTENUATION,1.0);
  glLightf(GL_LIGHT0,GL_LINEAR_ATTENUATION,0.0);
  glLightf(GL_LIGHT0,GL_QUADRATIC_ATTENUATION,0.0);

  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
}

GLvoid set_material_properties ( GLfloat r, GLfloat g, GLfloat b )
{
  GLfloat mat_specular[4] = { 0.0, 0.0, 0.0, 1.0 };
  GLfloat mat_ambient_and_diffuse[4] = { 0.5, 0.5, 0.5, 1.0 };
  GLfloat mat_shininess[1] = { 0.0 };
  
  mat_specular[0] = mat_ambient_and_diffuse[0] = r;
  mat_specular[1] = mat_ambient_and_diffuse[1] = g;
  mat_specular[2] = mat_ambient_and_diffuse[2] = b;

  glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
  glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
  glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, mat_ambient_and_diffuse);
 
}

/* --------------------------------------------- */
/* 
create display list: axis-oriented cube centered at the origin, with
edge length = 2
*/

GLuint create_unit_cube ( )
{
  GLuint sceneList = glGenLists(1);

  glNewList(sceneList,GL_COMPILE);

  glBegin(GL_QUADS);

  glNormal3f(0.0,0.0,-1.0);

  glVertex3f(1.0,1.0,-1.0);
  glVertex3f(1.0,-1.0,-1.0);
  glVertex3f(-1.0,-1.0,-1.0);
  glVertex3f(-1.0,1.0,-1.0);
  
  glNormal3f(0.0,0.0,1.0);

  glVertex3f(1.0,1.0,1.0);
  glVertex3f(-1.0,1.0,1.0);
  glVertex3f(-1.0,-1.0,1.0);
  glVertex3f(1.0,-1.0,1.0);

  glNormal3f(1.0,0.0,0.0);

  glVertex3f(1.0,-1.0,1.0);
  glVertex3f(1.0,-1.0,-1.0);
  glVertex3f(1.0,1.0,-1.0);
  glVertex3f(1.0,1.0,1.0);

  glNormal3f(-1.0,0.0,0.0);

  glVertex3f(-1.0,-1.0,1.0);
  glVertex3f(-1.0,1.0,1.0);
  glVertex3f(-1.0,1.0,-1.0);
  glVertex3f(-1.0,-1.0,-1.0);

  glNormal3f(0.0,1.0,0.0);

  glVertex3f(-1.0,1.0,1.0);
  glVertex3f(1.0,1.0,1.0);
  glVertex3f(1.0,1.0,-1.0);
  glVertex3f(-1.0,1.0,-1.0);

  glNormal3f(0.0,-1.0,0.0);

  glVertex3f(-1.0,-1.0,-1.0);
  glVertex3f(1.0,-1.0,-1.0);
  glVertex3f(1.0,-1.0,1.0);
  glVertex3f(-1.0,-1.0,1.0);

  glEnd();

  glEndList();

  return sceneList;
}


GLuint create_scene ( )
{
  GLuint cubeList = create_unit_cube();
  GLuint sceneList = glGenLists(1);

  glNewList(sceneList,GL_COMPILE);

  set_material_properties(1.0,1.0,1.0);

  glCallList(cubeList);

  set_material_properties(1.0,0.0,0.0);

  glPushMatrix();
    glTranslatef(-1.0,-1.0,-1.0);
    glScalef(.4,.4,.4);
    glCallList(cubeList);
  glPopMatrix();

  set_material_properties(0.0,1.0,0.0);
  
  glPushMatrix();
    glTranslatef(-1.0,-1.0,1.0);
    glScalef(.4,.4,.4);
    glCallList(cubeList);
  glPopMatrix();

  set_material_properties(0.0,0.0,1.0);
  
  glPushMatrix();
    glTranslatef(-1.0,1.0,-1.0);
    glScalef(.4,.4,.4);
    glCallList(cubeList);
  glPopMatrix();
  
  set_material_properties(0.5,0.0,0.5);

  glPushMatrix();
    glTranslatef(1.0,-1.0,-1.0);
    glScalef(.4,.4,.4);
    glCallList(cubeList);
  glPopMatrix();

  glEndList();

  return sceneList;
}

/* --------------------------------------------- */

/* redraw the scene */

GLvoid draw(GLvoid)
{
  /* set the projection matrix */
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(8.0,1.0,15.0,25.0);

  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();

  /* initialize light */
  init_lightsource();

  if (animate)
    {
      angle1 += dangle1;
      angle2 += dangle2;
    }

  glTranslatef(0,0,-20);
  glRotatef(angle1,1,2,3);
  glRotatef(angle2,-2,-1,0);

  /* ensure we're drawing to the correct GLUT window */
  glutSetWindow(wid);

  /* clear the color buffers */
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  /* DRAW WHAT IS IN THE DISPLAY LIST */
  glCallList(sceneID);
   
  /* flush the pipeline */
  glFlush();

  /* look at our handiwork */
  glutSwapBuffers();

  if (animate)
    glutPostRedisplay();
}

/* --------------------------------------------- */

/* handle mouse events */

GLvoid mouse_button(GLint btn, GLint state, GLint mx, GLint my)
{
  switch( btn ) {
    case GLUT_LEFT_BUTTON:
      printf("Left Button"); // remove this line from your final submission
      switch( state ) {
        case GLUT_DOWN: 
	  printf(" down\n"); // remove this line from your final submission
	  break;
        case GLUT_UP:   
	  printf(" up\n"); // remove this line from your final submission
	  break;
      }
      break;
    case GLUT_MIDDLE_BUTTON:
      printf("Middle Button"); // remove this line from your final submission
      switch( state ) {
        case GLUT_DOWN: 
	  printf(" down\n"); // remove this line from your final submission
	  break;
        case GLUT_UP:   
	  printf(" up\n"); // remove this line from your final submission
	  break;
      }
      break;
    case GLUT_RIGHT_BUTTON:
      printf("Right Button"); // remove this line from your final submission
      switch( state ) {
        case GLUT_DOWN: 
	  printf(" down\n"); // remove this line from your final submission
	  break;
        case GLUT_UP:   
	  printf(" up\n"); // remove this line from your final submission
	  break;
      }
      break;
  }
}

GLvoid button_motion(GLint mx, GLint my)
{
  printf("Motion with button down: %d %d\n",mx,my); // remove this line from your final submission
  return;
}

GLvoid passive_motion(GLint mx, GLint my)
{
  printf("Passive Motion: %d %d\n",mx,my); // remove this line from your final submission
  return;
}

/* --------------------------------------------- */

/* handle keyboard events; here, just exit if ESC is hit */

GLvoid keyboard(GLubyte key, GLint x, GLint y)
{
  switch(key) {
    case 27:  /* ESC */
              exit(0);

    default:  break;
  }
}

/* --------------------------------------------- */

GLvoid menu ( int value )
{
  switch(value)
    {
    case MENU_SLOWER:
      dangle1 *= .5;
      dangle2 *= .5;
      break;
    case MENU_FASTER:
      dangle1 *= 1.5;
      dangle2 *= 1.5;
      break;
    case MENU_STOP_RUN:
      animate = !animate;
      break;
    }
}

/* --------------------------------------------- */

/* handle resizing the glut window */

GLvoid reshape(GLint vpw, GLint vph)
{
  glutSetWindow(wid);

  /* maintain a square viewport, not too small, not too big */
  if( vpw < vph ) vpd = vph;
  else            vpd = vpw;

  if( vpd < VPD_MIN ) vpd = VPD_MIN;
  if( vpd > VPD_MAX ) vpd = VPD_MAX;

  glViewport(0, 0, vpd, vpd);
  glutReshapeWindow(vpd, vpd);

  glutPostRedisplay();
}

/* --------------------------------------------- */

GLint init_glut(GLint *argc, char **argv)
{
  GLint id;

  glutInit(argc,argv);

  /* size and placement hints to the window system */
  glutInitWindowSize(vpd, vpd);
  glutInitWindowPosition(10,10);

  /* double buffered, RGB color mode */
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);

  /* create a GLUT window (not drawn until glutMainLoop() is entered) */
  id = glutCreateWindow("cs4451 assignment 2");    

  /* register callbacks */

  /* window size changes */
  glutReshapeFunc(reshape);

  /* keypress handling when the current window has input focus */
  glutKeyboardFunc(keyboard);

  /* mouse event handling */
  glutMouseFunc(mouse_button);           /* button press/release        */
  glutMotionFunc(button_motion);         /* mouse motion w/ button down */
  glutPassiveMotionFunc(passive_motion); /* mouse motion with button up */

  /* window obscured/revealed event handler */
  glutVisibilityFunc(NULL);

  /* handling of keyboard SHIFT, ALT, CTRL keys */
  glutSpecialFunc(NULL);

  /* what to do when mouse cursor enters/exits the current window */
  glutEntryFunc(NULL);

  /* what to do on each display loop iteration */
  glutDisplayFunc(draw);

  /* create menu */
  GLint menuID = glutCreateMenu(menu);
  glutAddMenuEntry("slower",MENU_SLOWER);
  glutAddMenuEntry("faster",MENU_FASTER);
  glutAddMenuEntry("stop/run",MENU_STOP_RUN);
  glutSetMenu(menuID);
  glutAttachMenu(GLUT_RIGHT_BUTTON);

  return id;
}

/* --------------------------------------------- */

GLvoid init_opengl(GLvoid)
{
  /* back-face culling on */
  glEnable(GL_CULL_FACE);
  glCullFace(GL_BACK);

  /* automatically scale normals to unit length after transformation */
  glEnable(GL_NORMALIZE);

  /* clear to BLACK */
  glClearColor(0.0, 0.0, 0.0, 1.0);

  /* Enable depth test  */
  glEnable(GL_DEPTH_TEST);
}

/* --------------------------------------------- */

GLint main(GLint argc, char **argv)
{  /* initialize light */
  init_lightsource();

  /* initialize GLUT: register callbacks, etc */
  wid = init_glut(&argc, argv);

  /* any OpenGL state initialization we need to do */
  init_opengl();

  /* CREATE THE DISPLAY LIST FOR THE SCENE */
  sceneID = create_scene();

  glutMainLoop();

  return 0;
}