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)) return;
  20             throw new Error("rebind attempt: "+this+" and "+other+" with "
  21                             + bindingMatrix
  22                             + "; expected "
  23                             + getBindingMatrix(other));
  24         }
  25
  26         bindingMatrix =
  27             getBindingMatrix()
  28             .times(bindingMatrix)
  29             .times(other.getBindingMatrix());
  30         other.bindingGroup.merge(bindingGroup, bindingMatrix);
  31     }
  32
  33     public Matrix getBindingMatrix() {
  34         if (bindingGroup==null) return Matrix.ONE;
  35         return bindingGroup.getMatrix(this);
  36     }
  37
  38     public Matrix getBindingMatrix(HasBindingGroup other) {
  39         return bindingGroup.getMatrix(this, other);
  40     }
  41
  42     public HasBindingGroup getMaster() {
  43         if (bindingGroup==null) return this;
  44         return bindingGroup.getMaster();
  45     }
  46
  47     public void unbind() {
  48         if (bindingGroup==null) return;
  49         bindingGroup.unbind(this);
  50         bindingGroup = null;
  51         bindingGroupChanged(bindingGroup);
  52     }
  53
  54     public boolean isBoundTo(HasBindingGroup t) {
  55         return bindingGroup.contains(t);
  56     }
  57
  58     public Iterable getBoundPeers() {
  59         if (bindingGroup==null) bindingGroup = new BindingGroup(this);
  60         return bindingGroup;
  61     }
  62     public void bindingGroupChanged(BindingGroup newBindingGroup) { }
  63 }