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(HasBindingGroup other, Matrix bindingMatrix) {
  15         if (other.bindingGroup == this.bindingGroup)
  16             throw new Error("rebind attempt");
  17
  18         bindingMatrix =
  19             getBindingMatrix()
  20             .times(bindingMatrix)
  21             .times(other.getBindingMatrix());
  22         other.bindingGroup.merge(bindingGroup, bindingMatrix);
  23     }
  24
  25     public Matrix getBindingMatrix() {
  26         return bindingGroup.getMatrix(this);
  27     }
  28
  29     public HasBindingGroup getMaster() {
  30         return bindingGroup.getMaster();
  31     }
  32
  33 }