// 3d-move.c

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

double WIDTH = 800;
double HEIGHT = 800;

GLboolean motion = GL_TRUE;
GLfloat xangle = 0.0, yangle = 0.0, xspin = 0.0, yspin = 0.0;
GLfloat size = 1.0, factor = 10.0;
GLboolean leftb = GL_FALSE, middleb = GL_FALSE;

void keyboard(unsigned char key, int x, int y)
{
  switch (key) {
  case 27:             /* ESC */
  case 'q':
  case 'Q':
    exit(0);
  case 'r':
  case 'R':
    xangle = 0.0;
    yangle = 0.0;
    size = 1.0;
    xspin = 0.0;
    yspin = 0.0;
  }
}

void update(void)
{
  if (!leftb){
    xangle -= xspin;
    yangle -= yspin;
  }
  glutPostRedisplay();
}

void init(void)
{

}

void Draw(void)
{
  GLfloat objectColor[] = {1.0, 0.0, 0.0, 1.0};
  glColor3fv(objectColor);

  glPushMatrix();
  {
      glTranslatef(WIDTH/2, HEIGHT/2, 0.0);
//    glutSolidCube(300);
//    glutWireCube(300);
//    glutSolidSphere(150, 15, 15);
//    glutWireSphere(150, 15, 15);
//    glutSolidCone(200, 150, 10, 10);
//    glutWireCone(200, 150, 10, 10);
//    glutSolidTorus(30, 150, 20, 20);
//    glutWireTorus(30, 150, 20, 20);
//    glScalef(100.0, 100.0, 100.0);
//    glutSolidDodecahedron();
//    glScalef(100.0, 100.0, 100.0);
//    glutWireDodecahedron();
//    glutSolidTeapot(100);
      glutWireTeapot(100);
  }
  glPopMatrix();
}

void draw(void)
{
  int t, f;

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  glPushMatrix();
  {
    glTranslatef(WIDTH / 2, HEIGHT / 2, 0);
    glScalef(size, size, size);
    glRotatef(xangle, 0.0, 1.0, 0.0);
    glRotatef(yangle, 1.0, 0.0, 0.0);
    glTranslatef(-WIDTH / 2, -HEIGHT / 2, 0);
    Draw();
  }
  glPopMatrix();
  glutSwapBuffers();
}

int oldx, oldy;

void mouse(int button, int state, int x, int y)
{
  if (button == GLUT_LEFT_BUTTON) {
    oldx = x;
    oldy = y;
    if (state == GLUT_DOWN)
      leftb = GL_TRUE;
    else
      leftb = GL_FALSE;
  }
  if (button == GLUT_MIDDLE_BUTTON) {
    oldx = x;
    oldy = y;
    if (state == GLUT_DOWN)
      middleb = GL_TRUE;
    else
      middleb = GL_FALSE; 
  } 
}

void visibility(int state)
{
  if (state == GLUT_VISIBLE && motion) {
    glutIdleFunc(update);
  } else {
    glutIdleFunc(NULL);
  }
}

void mouse_motion(int x, int y)
{
  if (leftb) {
    xspin = x/factor - oldx/factor;
    xangle -= xspin;
    yspin = y/factor - oldy/factor;
    yangle -= yspin;
  }
  if (middleb) {
    size -= y/factor - oldy/factor;
    if (size < 0.0)
       size = 0.0;
  }
  oldx = x;
  oldy = y;
  glutPostRedisplay();
}

int main(int argc, char *argv[])
{
  int i;

  glutInit(&argc, argv);
  glutInitWindowSize(WIDTH, HEIGHT);
  glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH);
  glutCreateWindow("3D Move Program");
  glutDisplayFunc(draw);
  glutKeyboardFunc(keyboard);

  glViewport(0, 0, WIDTH, HEIGHT);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glOrtho(0, WIDTH, 0, HEIGHT, -10000, 10000);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  glClearColor(0, 0, 0, 0);
  glClearDepth(1.0);

  glEnable(GL_CULL_FACE);
  glEnable(GL_DEPTH_TEST);

  glutMouseFunc(mouse);
  glutMotionFunc(mouse_motion);
  glutVisibilityFunc(visibility);

  init();

  glutMainLoop();
  return 0;
}