# ifndef _SGL_SHAPES
# include "sgl_shapes.h"
# endif

# define _SGL_LINKS

typedef enum {  NO_ACTION = 0,
		POINT_TO_POINT,
		ROTATE_ABOUT_POINT,
		SCALE_FACTOR
	     } SGLLinkMode;

typedef enum {  LINEAR,
		QUADRATIC,
		SINE
	     } SGLLinkIterMode;

		
/*******************************************************
 *						link ptr
 *******************************************************/
class linkptr {
  public:
    Shape   * link;
    linkptr * next;

    linkptr() {
	link=NULL; next=NULL;
    }
    linkptr(Shape & newlink) {
	link = & newlink;
	next = NULL;
    }
    linkptr(Shape & newlink, linkptr & previous) { 
	next = & previous;
	link = & newlink;
    }
    ~linkptr() {}
};

/*******************************************************
 *						   links
 *******************************************************/
class Link: public Shape {
  public:
    SGLLinkMode 	mode;
    SGLLinkIterMode	imode;
    GLdouble 		xf,yf,zf;
    GLdouble 		dx, dy, dz;
    GLdouble		p0, p1, p2;
    GLfloat	      * time;
    boolean		enabled;
    long 		tstart,tend;
    linkptr 	      * head;
    linkptr 	      * tail;

    Link() : Shape() {
	head=tail=NULL;
	xf=yf=zf=1.0;
	mode=NO_ACTION;
	time=NULL;
	enabled=true;
    };

    Link(SGLLinkMode modei) : Shape() {
	head=tail=NULL;
	xf=yf=zf=1.0;
	enabled=true;
	time=NULL;
	setMode(modei);
    };

    Link(Shape & newlink) : Shape() {
	tail=head= new linkptr(newlink);
	xf=yf=zf=1.0;
	mode=NO_ACTION;
	enabled=true;
	time=NULL;
    };

    Link(Shape & newlink, SGLLinkMode modei) : Shape() {
	tail=head= new linkptr(newlink);
	xf=yf=zf=1.0;
	setMode(modei);
	time=NULL;
	enabled=true;
    };

    ~Link();

    SGLLinkMode getMode() { return mode; }
    SGLLinkIterMode getIterMode() { return imode; }
    long getStartTime() { return tstart; }
    long getEndTime() { return tend; }

    boolean isEnabled() { return enabled; }
    void setEnabled(boolean enabledi) { enabled=enabledi; };
    void enable() { enabled=true; }
    void disable() { enabled=false; }
    boolean active();

    void setScale(GLdouble xfi,GLdouble yfi,GLdouble zfi) 
	 { xf=xfi; yf=yfi; zf=zfi; };
    void setMode(SGLLinkMode modei);
    void setMode(SGLLinkMode modei, SGLLinkIterMode imodei);
    void setMode(SGLLinkMode modei, SGLLinkIterMode imodei,
		 GLdouble dxi, GLdouble dyi, GLdouble dzi);
    void setIterMode(SGLLinkIterMode imodei);
    void setIterMode(SGLLinkIterMode imodei,
		 GLdouble p0i, GLdouble p1i, GLdouble p2i);
    void setChange (GLdouble dxi, GLdouble dyi, GLdouble dzi)
  	 { dx=dxi; dy=dyi; dz=dzi; } ;
    void setIterParms (GLdouble p0i, GLdouble p1i, GLdouble p2i)
  	 { p0=p0i; p1=p1i; p2=p2i; } ;
    void setTimeInterval (long tstarti, long tendi)
	{ tstart=tstarti; tend=tendi; };
    void setStartTime (long tstarti) { tstart=tstarti; };
    void setEndTime (long tendi) { tend=tendi; };

    void add(Shape & newlink);
    void iterate();
    void paint();
    void print();
    boolean linksOptimizable();
    boolean optimizable();
    void optimizePaint();

    void settime(GLfloat & timei) { time= & timei; }
    long gettime() {
      if (time==NULL) {
        cerr << "time not initialized for ";
	print();
	exit(0);
      }
      return *time;
    }
};