#include <stdio.h>
#include <stdlib.h>
#include <cave_ogl.h>
#include <math.h>
#include <GL/glu.h>

static GLuint fontbase=0, sphereDL;
static GLUquadricObj *sphereObj; 
static float redMaterial[] = { 1, 0, 0, 1 };
static int *numspheres;

static void LoadTextFont(Display *display,char *fontname)
{
 XFontStruct *fontinfo=NULL;
 fontinfo = XLoadQueryFont(display,fontname);
 if ((fontinfo) && (!fontinfo->min_byte1) && (!fontinfo->max_byte1))
	{
	fontbase = glGenLists(fontinfo->max_char_or_byte2);
	glXUseXFont(fontinfo->fid,0,fontinfo->max_char_or_byte2,fontbase);
	}
 else
	fprintf(stderr,"ERROR: failed to load font \"%s\"\n",fontname);
}

void DrawText(char *string)
{
 if (fontbase)
	{
	glPushAttrib(GL_LIST_BIT);
	glListBase(fontbase);
	glCallLists(strlen(string),GL_UNSIGNED_BYTE,(GLubyte *)string);
	glPopAttrib();
	}
}


void init_font(void)
{
  LoadTextFont(CAVEXDisplay(),"fixed");
}

void init_ball(void)
{
  glEnable(GL_LIGHT0);
  glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, redMaterial);
  sphereObj = gluNewQuadric();
  /* gluQuadricDrawStyle(sphereObj, GLU_LINE); */
  sphereDL = glGenLists(1);
  glNewList(sphereDL, GL_COMPILE);
     gluSphere(sphereObj, 1.0, 32, 32);
  glEndList();
}

void init_all(void)
{
  init_font();
  init_ball();
}

void draw_text(void)
{
 char str[256];
 float pos[3],ori[3];

 glMatrixMode(GL_PROJECTION);
 glLoadIdentity();
 glOrtho(0.0,10.0,0.0,10.0,-100.0,100.0);
 glMatrixMode(GL_MODELVIEW);
 glLoadIdentity();
 glColor3f(1.0,1.0,1.0);

 glRasterPos2f(1.0, 9.0);
 sprintf(str, "Time: %.1f   FPS: %.1f ", *CAVETime,*CAVEFramesPerSecond);
 DrawText(str);

 glRasterPos2f(1.0,8.7); 
 CAVEGetPosition(CAVE_HEAD,pos);
 CAVEGetOrientation(CAVE_HEAD,ori);
 sprintf(str, "Sensor Position: (%.2f,%.2f,%.2f)"
		"   Orientation:(%.2f,%.2f,%.2f)",
		pos[0],pos[1],pos[2],ori[0],ori[1],ori[2]);
 DrawText(str);

 glRasterPos2f(1.0,8.4); 
 sprintf(str, "Number of spheres: %d", *numspheres);
 DrawText(str);

}
    	

void draw_balls(int n)
{
  int i;

  glEnable(GL_LIGHTING);
  glPushMatrix();  
  glTranslatef(-5.0, 5.0, -4.0); 
  for (i = 0; i < n; i++) {
    glCallList(sphereDL);
    glTranslatef(-1.0, 0.0, 0.0);
  }
  glPopMatrix();
  glDisable(GL_LIGHTING);
   
} 

void draw_all(void)
{
 glClearColor(0.0, 0.0, 0.0, 1.0);
 glClear(GL_COLOR_BUFFER_BIT);
 glClear(GL_DEPTH_BUFFER_BIT);

 draw_balls(*numspheres);
 draw_text();
}

main(int argc, char* argv[])
{
 CAVEConfigure(&argc, argv, NULL);
 numspheres = CAVEMalloc(sizeof(int));
 *numspheres = 0;
 CAVEInit();
 CAVEInitApplication(init_all, 0);
 CAVEDisplay(draw_all, 0);
 while (!CAVEgetbutton(CAVE_ESCKEY)) {
   if (CAVEButtonChange(1) == 1) {
     (*numspheres)++;
     /* printf("increasing to %d\n",  *numspheres); */
   }
   if (CAVEButtonChange(3) == 1) {
     (*numspheres)--;
     /* printf("decreasing to %d\n",  *numspheres); */
   }
   if (CAVEButtonChange(2) == 1)
     *numspheres = 0;
   sginap(1);
 }
 CAVEExit();
}