Following.java

/*
 *  This file is part of the Haven & Hearth game client.
 *  Copyright (C) 2009 Fredrik Tolf <fredrik@dolda2000.com>, and
 *                     Björn Johannessen <johannessen.bjorn@gmail.com>
 *
 *  Redistribution and/or modification of this file is subject to the
 *  terms of the GNU Lesser General Public License, version 3, as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  Other parts of this source tree adhere to other copying
 *  rights. Please see the file `COPYING' in the root directory of the
 *  source tree for details.
 *
 *  A copy the GNU Lesser General Public License is distributed along
 *  with the source tree of which this file is a part in the file
 *  `doc/LPGL-3'. If it is missing for any reason, please see the Free
 *  Software Foundation's website at <http://www.fsf.org/>, or write
 *  to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 *  Boston, MA 02111-1307 USA
 */

package haven;

public class Following extends Moving {
    long tgt;
    double lastv = 0.0;
    Indir<Resource> xfres;
    String xfname;
    GLState xf = null, lpxf = null;
    Gob lxfb = null;
    Skeleton.Pose lpose = null;
    
    public Following(Gob gob, long tgt, Indir<Resource> xfres, String xfname) {
	super(gob);
	this.tgt = tgt;
	this.xfres = xfres;
	this.xfname = xfname;
    }
    
    public Coord3f getc() {
	Gob tgt = gob.glob.oc.getgob(this.tgt);
	if(tgt == null)
	    return(gob.getrc());
	return(tgt.getc());
    }
    
    public double getv() {
	Gob tgt = gob.glob.oc.getgob(this.tgt);
	if(tgt != null) {
	    Moving mv = tgt.getattr(Moving.class);
	    if(mv == null)
		lastv = 0.0;
	    else
		lastv = mv.getv();
	}
	return(lastv);
    }
    
    public Gob tgt() {
	return(gob.glob.oc.getgob(this.tgt));
    }
    
    private Skeleton.Pose getpose(Gob tgt) {
	if(tgt == null)
	    return(null);
	return(tgt.getattr(Drawable.class).getpose());
    }

    public GLState xf() {
	synchronized(this) {
	    Gob tgt = tgt();
	    Skeleton.Pose cpose = getpose(tgt);
	    GLState pxf = xf(tgt);
	    if((xf == null) || (cpose != lpose) || (lpxf != pxf)) {
		if(tgt == null) {
		    xf = null;
		    lpose = null;
		    lxfb = null;
		    lpxf = null;
		    return(null);
		}
		Skeleton.BoneOffset bo = xfres.get().layer(Skeleton.BoneOffset.class, xfname);
		if(bo == null)
		    throw(new RuntimeException("No such boneoffset in " + xfres.get() + ": " + xfname));
		if(pxf != null)
		    xf = GLState.compose(pxf, bo.forpose(cpose));
		else
		    xf = GLState.compose(tgt.loc, bo.forpose(cpose));
		lpxf = pxf;
		lxfb = tgt;
		lpose = cpose;
	    }
	}
	return(xf);
    }

    public static GLState xf(Gob gob) {
	if(gob == null)
	    return(null);
	Following flw = gob.getattr(Following.class);
	if(flw == null)
	    return(null);
	return(flw.xf());
    }
}