/*
     Simple 3D graphics routines - academic use only - by Chuck Liang,
     Hofstra University Computer Science

	C++/Gtk+ version
*/

#include "boxworld.h"

    double boxworld::toRadians(int degrees)
    { return degrees * M_PI / 180.0; }

    void boxworld::setSR(double s) {SR = s;}
    void boxworld::setZR(double z) {ZR=z;}
    void boxworld::tilt(int d) {tiltR=toRadians(d);}

    boxworld::boxworld(int xd, int yd, int zd, double zr0, int trd)
    {
        ZR = 0.5;  tiltR = M_PI/2.0;  SR = 1.0;
	XDIM=xd; YDIM=yd; ZDIM=zd;
	ZR=zr0; tiltR = toRadians(trd);
        xshift = (int)(ZDIM * cos(tiltR) * SR);
        yshift = (int)(ZDIM * sin(tiltR) * SR);
    }

    boxworld::boxworld(int xd, int yd, int zd, double zr0, int trd, double sr0)
    {
        ZR = 0.5;  tiltR = M_PI/2.0; 
	XDIM=xd; YDIM=yd; ZDIM=zd;
	ZR=zr0; tiltR = toRadians(trd);
	SR = sr0;
        xshift = (int)(ZDIM * cos(tiltR)*SR);
        yshift = (int)(ZDIM * sin(tiltR)*SR);
       // note that here SR does not affect xshift, yshift
    }

// critical function to convert 3d coordinate to 2d coordinate stored in 
// x2 and y2; returns 0 on success
int boxworld::point(int x, int y, int z, int *x2, int *y2)
{
  double s;
  s = (1-((1-ZR)*z/((double)ZDIM)));
  *x2 = (int) ((s*x) + (z * cos(tiltR) * SR));
  *y2 = (int) ((s*y) + (z * sin(tiltR) * SR));
  *y2 += (int)abs(yshift);
  if(xshift<0) *x2 -= (int)xshift;
  return 0;
}

void boxworld::drawbox(Glib::RefPtr<Gdk::Drawable> win,
  int x0, int y0, int z0, int xd, int yd, int zd,
	     Glib::RefPtr<Gdk::GC> gc)
{
  int a, b, u, v, x, y, p, q;
  point(x0,y0,z0,&a,&b);
  point(x0+xd,y0,z0,&x,&y);
  point(x0,y0+yd,z0,&u,&v);
  point(x0+xd,y0+yd,z0,&p,&q);
  // front
  win->draw_line(gc,a,b,x,y);
  win->draw_line(gc,a,b,u,v);
  win->draw_line(gc,u,v,p,q);
  win->draw_line(gc,p,q,x,y);
  // sides
  point(x0,y0,z0+zd,&x,&y);
  point(x0,y0+yd,z0+zd,&p,&q);
  win->draw_line(gc,a,b,x,y);  
  win->draw_line(gc,u,v,p,q);
  win->draw_line(gc,x,y,p,q);
  point(x0+xd,y0,z0+zd,&a,&b);
  point(x0+xd,y0+yd,z0+zd,&u,&v);
  win->draw_line(gc,x,y,a,b);
  win->draw_line(gc,p,q,u,v);
  win->draw_line(gc,a,b,u,v);
  point(x0+xd,y0,z0,&x,&y);
  point(x0+xd,y0+yd,z0,&p,&q);
  win->draw_line(gc,a,b,x,y);
  win->draw_line(gc,u,v,p,q);
}

void boxworld::drawline(Glib::RefPtr<Gdk::Drawable> win, 
  int x0, int y0, int z0, int x1, int y1, int z1, 
	      Glib::RefPtr<Gdk::GC> gc)
{  int a, b, x, y;
   point(x0,y0,z0,&a,&b);
   point(x1,y1,z1,&x,&y);
   win->draw_line(gc,a,b,x,y);
}

// fill circle with scaled radius
void boxworld::drawcircle(Glib::RefPtr<Gdk::Drawable> win, bool filled,
   int x0, int y0, int z0, double r, Glib::RefPtr<Gdk::GC> gc)
{
  int x, y;  double rs;   
  int cx, cy;  // corners of rectangle
  point(x0,y0,z0,&x,&y);
  rs = (1-((1-ZR)*((double)z0)/ZDIM)) * r;
  if (rs<1) rs = 1;
  cx = (int)(x-rs);  cy = (int)(y-rs);
  win->draw_arc(gc,filled,cx,cy,(int)(2*rs),(int)(2*rs),0,360*64);
}

double boxworld::dscale(double x, double z0)
{
  return (1-((1-ZR)*((double)z0)/ZDIM)) * x;
}


// draw image to scale - w,h represent the original size of the image
void boxworld::drawimage(Glib::RefPtr<Gdk::Drawable> win,
		      Glib::RefPtr<Gdk::GC> gc,
		      Glib::RefPtr<Gdk::Pixbuf> image,
		      int x, int y, int z, int w, int h)
{
    int ws, hs, x2, y2; 
    point(x,y,z,&x2,&y2);
    ws = (int)dscale(w,z);     hs = (int)dscale(h,z);

    win->draw_pixbuf(gc,image,0,0,x2,y2,ws,hs,Gdk::RGB_DITHER_NONE,0,0);
    //    image->render_to_drawable(win,gc,
    //			      0,0,x2,y2, ws,hs,Gdk::RGB_DITHER_NONE,0,0);
}

// fixed original w, h:
void boxworld::drawimage(Glib::RefPtr<Gdk::Drawable> win,
		      Glib::RefPtr<Gdk::GC> gc,
		      Glib::RefPtr<Gdk::Pixbuf> image,
		      int x, int y, int z)
{
    int w, h, ws, hs, x2, y2;
    point(x,y,z,&x2,&y2);
    w = image->get_width();  h = image->get_height();
    ws = (int)dscale(w,z);  hs = (int)dscale(h,z);
    win->draw_pixbuf(gc,image,0,0,x2,y2,ws,hs,Gdk::RGB_DITHER_NONE,0,0);
    //    image->render_to_drawable(win,gc,
    //			      0,0,x2,y2, ws,hs,Gdk::RGB_DITHER_NONE,0,0);
}

 
// suggested window width and height
int boxworld::wwidth() 
{ return (int) (XDIM+abs(xshift)+20);}
int boxworld::wheight()
{ return (int) (YDIM+abs(yshift)+40);}


// g++ -c boxworld.cpp `pkg-config gtkmm-2.0 --cflags --libs`