/*
	Simple 3D recursive tree
	(C) Bedrich Benes	2005
/* bbenes ~ at ~ purdue.edu*/


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

GLUquadric *q;
GLint n=1;

void Init(void) 
{
   glClearColor(1,1,1,1);
   glShadeModel(GL_FLAT);
   q=gluNewQuadric();
   glNewList(1,GL_COMPILE);
   gluCylinder(q,1.f,1.f,1.f,5.f,5.f);
   glEndList();

}

void Display(void)
{

}

void RenderRandom(int n)
{
  GLfloat size;

  glColor3ub(0,0,0);
	glPushMatrix();
	size=(GLfloat)rand()/RAND_MAX*0.5+1;
	glScalef(0.1,0.1,size);
    glCallList(1);
    glPopMatrix();
      glTranslatef(0,0,size);
  if (n==0) return;
	  glPushMatrix();
        glRotatef(-180*(GLfloat)rand()/RAND_MAX,0,0,1);
	    glRotatef(15+(GLfloat)rand()/RAND_MAX,1,0,0);
        RenderRandom(n-1);
      glPopMatrix();
      glPushMatrix();
        glRotatef(180*(GLfloat)rand()/RAND_MAX,0,0,1);
        glRotatef(-15-30*(GLfloat)rand()/RAND_MAX,1,0,0);
        RenderRandom(n-1);
      glPopMatrix();

}

void Render(int n)
{

  glColor3ub(0,0,0);
	glPushMatrix();
	glScalef(0.05,0.05,1);
    glCallList(1);
    glPopMatrix();
      glTranslatef(0,0,1);
  if (n==0) return;
//	  glPushMatrix();
//        glRotatef(90,0,0,1);
//	    glRotatef(30,1,0,0);
//        Render(n-1);
//      glPopMatrix();
      glPushMatrix();
        glRotatef(180,0,0,1);
        glRotatef(30,1,0,0);
        Render(n-1);
      glPopMatrix();
//	  glPushMatrix();
//        glRotatef(270,0,0,1);
//	    glRotatef(30,1,0,0);
//        Render(n-1);
//      glPopMatrix();
	  glPushMatrix();
	    glRotatef(30,1,0,0);
        Render(n-1);
      glPopMatrix();
}


void Idle(void)
{
   static a;
	
   srand(2);//random numbers generator seed
   glClear(GL_COLOR_BUFFER_BIT);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
   glTranslatef(0,-1,0);
   glRotatef(-90,1,0,0);
   glRotatef(90,0,0,1);

   glRotatef(a++,0,0,1);
   glScalef(0.3,0.3,0.3);
   RenderRandom(n);
   glutSwapBuffers();
}

void Reshape (int w, int h)
{
   glViewport (0, 0, (GLsizei) w, (GLsizei) h); 
   glMatrixMode (GL_PROJECTION);
   glLoadIdentity ();
   glOrtho(-2,2,-2,2,-20,20);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
}

void Keyboard (unsigned char key, int x, int y)
{
   switch (key) {
      case '+': n++; break;
      case '-': n--; break;
      case 27:
         exit(0);
         break;
      default:
         break;
   }
}

int main(int argc, char** argv)
{
   glutInit(&argc, argv);
   glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);
   glutInitWindowSize (700, 700); 
   glutInitWindowPosition (100, 100);
   glutCreateWindow("Tree");
   Init();
   glutDisplayFunc(Display); 
   glutIdleFunc(Idle); 
   glutReshapeFunc(Reshape);
   glutKeyboardFunc(Keyboard);
   glutMainLoop();
   return 0;
}