src/edu/berkeley/qfat/geom/HasBindingGroup.java

   1 package edu.berkeley.qfat.geom;
   2 import javax.media.opengl.*;
   3 import java.util.*;
   4
   5 public abstract class HasBindingGroup {
   6
   7     BindingGroup bindingGroup;
   8
   9     // know:      self   = bindingGroup[self] * master
  10     // know:      other  = other.bindingGroup[other] * other.bindingGroup.master
  11     // want:      self   = bindingMatrix * other
  12     // therefore: master = bindingGroup[self]^-1 * bindingMatrix * other
  13     // therefore:        = bindingGroup[self]^-1 * bindingMatrix * other.bindingGroup[other] * other.bindingGroup.master
  14     public void bindTo(Matrix bindingMatrix, HasBindingGroup other) {
  15         if (bindingGroup == null) bindingGroup = new BindingGroup(this);
  16         if (other.bindingGroup == null) other.bindingGroup = new BindingGroup(other);
  17
  18         if (other.bindingGroup == this.bindingGroup) {
  19             if (getBindingMatrix(other).equals(bindingMatrix))
  20                 return;
  21             throw new Error("rebind attempt: "+this+" and "+other+" with "
  22                             + bindingMatrix
  23                             + "; expected "
  24                             + getBindingMatrix(other));
  25         }
  26
  27         bindingMatrix =
  28             getBindingMatrix().inverse()
  29             .times(bindingMatrix)
  30             .times(other.getBindingMatrix());
  31         other.bindingGroup.merge(bindingGroup, bindingMatrix);
  32     }
  33
  34     public Matrix getBindingMatrix() {
  35         if (bindingGroup==null) return Matrix.ONE;
  36         return bindingGroup.getMatrix(this);
  37     }
  38
  39     public Matrix getBindingMatrix(HasBindingGroup other) {
  40         return bindingGroup.getMatrix(this, other);
  41     }
  42
  43     public HasBindingGroup getMaster() {
  44         if (bindingGroup==null) return this;
  45         return bindingGroup.getMaster();
  46     }
  47
  48     public void unbind() {
  49         if (bindingGroup==null) return;
  50         bindingGroup.unbind(this);
  51         bindingGroup = null;
  52         bindingGroupChanged(bindingGroup);
  53     }
  54
  55     public boolean isBoundTo(HasBindingGroup t) {
  56         return bindingGroup.contains(t);
  57     }
  58
  59     public Iterable getBoundPeers() {
  60         if (bindingGroup==null) bindingGroup = new BindingGroup(this);
  61         return bindingGroup;
  62     }
  63     public void bindingGroupChanged(BindingGroup newBindingGroup) { }
  64 }