import javax.swing.*;
import javax.media.opengl.*;
import javax.media.opengl.glu.*;
+import edu.wlu.cs.levy.CG.KDTree;
public class Geom implements Iterable<Geom.T> {
+ private KDTree kd = new KDTree(3);
+
public static float EPSILON = (float)0.000001;
+ public static Random random = new Random();
private HashMap<P,P> ps = new HashMap<P,P>();
- private HashMap<E,E> es = new HashMap<E,E>();
private HashSet<T> ts = new HashSet<T>();
public Iterator<T> iterator() { return ts.iterator(); }
+ public P newP(double x, double y, double z) { return newP((float)x, (float)y, (float)z); }
public P newP(float x, float y, float z) {
P p = new P(x, y, z);
P p2 = ps.get(p);
if (p2 != null) return p2;
ps.put(p,p);
+ p.name = allname++;
+ try { kd.insert(new double[]{p.x,p.y,p.z},p); } catch (Exception e) { throw new Error(e); }
return p;
}
- public E newE(P p1, P p2) {
- E e = new E(p1, p2);
- E e2 = es.get(e);
- if (e2 != null) return e2;
- es.put(e,e);
- return e;
- }
-
- /** ensures that e1.cross(e2).norm()==e2.cross(e3).norm()==e3.cross(e1).norm()==t.norm() */
- public T newT(E e1, E e2, E e3, V norm) {
- P p12 = e1.shared(e2);
- P p23 = e2.shared(e3);
- P p31 = e3.shared(e1);
+ public T newT(P p12, P p23, P p31, V norm) {
V norm2 = p31.minus(p12).cross(p23.minus(p12));
float dot = norm.dot(norm2);
if (Math.abs(dot) < EPSILON) throw new Error("dot products within epsilon of each other: "+norm+" "+norm2);
- if (dot < 0) { E t = e1; e1 = e3; e2 = e2; e3 = t; }
- if (e1.t1 != null && e1.t1.hasE(e1) && e1.t1.hasE(e2) && e1.t1.hasE(e3)) return e1.t1;
- if (e1.t2 != null && e1.t2.hasE(e1) && e1.t2.hasE(e2) && e1.t2.hasE(e3)) return e1.t2;
- if (e2.t1 != null && e2.t1.hasE(e1) && e2.t1.hasE(e2) && e2.t1.hasE(e3)) return e2.t1;
- if (e2.t2 != null && e2.t2.hasE(e1) && e2.t2.hasE(e2) && e2.t2.hasE(e3)) return e2.t2;
- if (e3.t1 != null && e3.t1.hasE(e1) && e3.t1.hasE(e2) && e3.t1.hasE(e3)) return e3.t1;
- if (e3.t2 != null && e3.t2.hasE(e1) && e3.t2.hasE(e2) && e3.t2.hasE(e3)) return e3.t2;
- T ret = new T(e1, e2, e3);
- ts.add(ret);
+ if (dot < 0) { P p = p12; p12=p23; p23 = p; }
+ return newT(p12, p23, p31);
+ }
+
+ public T newT(P p1, P p2, P p3) {
+ E e12 = p1.makeE(p2);
+ E e23 = p2.makeE(p3);
+ E e31 = p3.makeE(p1);
+ while(e12.next != e23 || e23.next != e31 || e31.next != e12) {
+ e12.makeAdjacent(e23);
+ e23.makeAdjacent(e31);
+ e31.makeAdjacent(e12);
+ }
+ T ret = e12.makeT();
+ if (e12.t == null) throw new Error();
+ if (e23.t == null) throw new Error();
+ if (e31.t == null) throw new Error();
return ret;
}
+ private char allname = 'A';
+
/** [UNIQUE] point in 3-space */
public final class P {
- public final float x, y, z;
- private T t = null; // any of the triangles incident at this point
- public P(float x, float y, float z) { this.x = x; this.y = y; this.z = z; }
+ char name;
+
+ float x, y, z;
+
+ private E e; // some edge *leaving* this point
+ private M binding = new M();
+ private P bound_to = this;
+
+ public E makeE(P p2) {
+ E e = getE(p2);
+ if (e != null) return e;
+ e = p2.getE(this);
+ if (this.e == null && p2.e == null) return this.e = new E(this, p2);
+ if (this.e == null && p2.e != null) return p2.makeE(this).pair;
+ return new E(getFreeIncident(), p2);
+ }
+
+ public E getFreeIncident() {
+ E ret = getFreeIncident(e, e);
+ if (ret != null) return ret;
+ ret = getFreeIncident(e.pair.next, e.pair.next);
+ if (ret == null) throw new Error("unable to find free incident to " + this);
+ return ret;
+ }
+
+ public E getFreeIncident(E start, E before) {
+ E e = start;
+ do {
+ if (e.pair.p2 == this && e.pair.t == null && e.pair.next.t == null) return e.pair;
+ e = e.pair.next;
+ } while(e != before);
+ return null;
+ }
+
+ public E getE(P p2) {
+ E e = this.e;
+ do {
+ if (e==null) return null;
+ if (e.p1 == this && e.p2 == p2) return e;
+ e = e.pair.next;
+ } while (e!=this.e);
+ return null;
+ }
+
+ public boolean isBoundTo(P p) {
+ P px = p;
+ do {
+ if (px==this) return true;
+ px = px.bound_to;
+ } while(px != p);
+ return false;
+ }
+
+ public void unbind() { bound_to = null; binding = null; }
+ public void bind(P p) { bind(p, new M()); }
+ public void bind(P p, M binding) {
+ if (isBoundTo(p)) return;
+ P temp_bound_to = p.bound_to;
+ M temp_binding = p.binding;
+ p.bound_to = this.bound_to;
+ p.binding = binding.times(this.binding); // FIXME: may have order wrong here
+ this.bound_to = temp_bound_to;
+ this.binding = temp_binding.times(temp_binding); // FIXME: may have order wrong here
+ }
+
+ public void move(V v) {
+ P p = this;
+ do {
+ p.x = p.x+v.x;
+ p.y = p.y+v.y;
+ p.z = p.z+v.z;
+ v = v.times(binding);
+ p = p.bound_to;
+ } while (p != this);
+ }
+
+ public P(float x, float y, float z) {
+ this.x = x; this.y = y; this.z = z;
+ }
+
+ public P nearest() {
+ Object[] results;
+ try { results = kd.nearest(new double[]{x,y,z},2); } catch (Exception e) { throw new Error(e); }
+ if (results[0] != this) throw new Error();
+ return (P)results[1];
+ }
+
public V minus(P p) { return new V(x-p.x, y-p.y, z-p.z); }
public P plus(V v) { return newP(x+v.x, y+v.y, z+v.z); }
+ public P times(M m) { return m.apply(this); }
public boolean equals(Object o) {
if (o==null || !(o instanceof P)) return false;
P p = (P)o;
return p.x==x && p.y==y && p.z==z;
}
+ // FIXME: moving a point alters its hashCode
public int hashCode() {
return
Float.floatToIntBits(x) ^
public void glVertex(GL gl) { gl.glVertex3f(x, y, z); }
public String toString() { return "("+x+","+y+","+z+")"; }
public V norm() {
- if (t==null) throw new Error("attempt to get vertex normal for point which does not belong to any triangles");
- T ti = t;
V norm = new V(0, 0, 0);
+ E e = this.e;
do {
- norm = norm.plus(ti.norm().times((float)ti.angle(this)));
- ti = ti.nextT(this);
- } while(ti != t);
+ if (e.t != null) norm = norm.plus(e.t.norm().times((float)e.prev.angle()));
+ e = e.pair.next;
+ } while(e != this.e);
return norm.norm();
}
}
/** vector in 3-space */
public final class V {
- private final float x, y, z;
+ public final float x, y, z;
+ public V(double x, double y, double z) { this((float)x, (float)y, (float)z); }
public V(float x, float y, float z) { this.x = x; this.y = y; this.z = z; }
public V cross(V v) { return new V(y*v.z-z*v.y, z*v.x-x*v.z, x*v.y-y*v.x); }
public V plus(V v) { return new V(x+v.x, y+v.y, z+v.z); }
- public V norm() { float m = mag(); return new V(x/m, y/m, z/m); }
+ public V norm() { return div(mag()); }
+ public V times(M m) { return m.apply(this); }
public float mag() { return (float)Math.sqrt(x*x+y*y+z*z); }
public float dot(V v) { return x*v.x + y*v.y + z*v.z; }
public V times(float mag) { return new V(x*mag, y*mag, z*mag); }
+ public V div(float mag) { return new V(x/mag, y/mag, z/mag); }
public String toString() { return "<"+x+","+y+","+z+">"; }
}
+ public class BindingGroup {
+ public HashSet<E> es = new HashSet<E>();
+ public BindingGroup() { }
+ public merge(E e) {
+ if (e.bg != null) merge(e.bg);
+ else { es.add(e); e.bg = this; }
+ }
+ public merge(BindingGroup bg) {
+ for(E e : bg.es) {
+ e.bg = this;
+ this.bg.add(e);
+ }
+ }
+ }
+
/** [UNIQUE] an edge */
public final class E {
public final P p1, p2;
- T t1, t2;
+ T t; // triangle to our "left"
+ E prev; // previous half-edge
+ E next; // next half-edge
+ E pair; // partner half-edge
+
+
+ public BindingGroup bg = null;
+
+ public void bind(E e) { bind(e, new M()); }
+ public void bind(E e, M m) {
+ if (e.bg != null) e.bg.merge(this);
+ else if (bg != null) bg.merge(e);
+ else {
+ bg = new BindingGroup();
+ bg.merge(this);
+ bg.merge(e);
+ }
+ }
+
+ public void dobind() {
+ if (bg==null) return;
+ for(E ex : bg.es) {
+ if (ex==this) continue;
+ p1.bind(ex.p1);
+ p2.bind(ex.p2);
+ }
+ }
+
+ public boolean destroyed = false;
+ public void shatter() {
+ if (destroyed) return;
+ /*
+ HashSet<E> eh = new HashSet<E>();
+ eh.add(this);
+ for(E ex = bound_to; ex != this; ex = ex.bound_to) eh.add(ex);
+ E[] es = (E[])eh.toArray(new E[0]);
+ */
+ destroy();
+ pair.shatter();
+ for(E ex = bound_to; ex != this; ex = ex.bound_to) ex.shatter();
+ }
+ public void destroy() {
+ this.destroyed = true;
+ }
+
+ private void sync() {
+ this.prev.next = this;
+ this.next.prev = this;
+ this.pair.pair = this;
+ if (this.next.p1 != p2) throw new Error();
+ if (this.prev.p2 != p1) throw new Error();
+ if (this.p1.e == null) this.p1.e = this;
+ }
+
+ public T makeT() { return t==null ? (t = new T(this)) : t; }
+
+ /** angle between this half-edge and the next */
+ public double angle() {
+ V v1 = next.p2.minus(p2);
+ V v2 = this.p1.minus(p2);
+ return Math.acos(v1.norm().dot(v2.norm()));
+ }
+
+ public void makeAdjacent(E e) {
+ if (this.next == e) return;
+ if (p2 != e.p1) throw new Error("cannot make adjacent -- no shared vertex");
+ if (t != null || e.t != null) throw new Error("cannot make adjacent -- edges not both free");
+
+ E freeIncident = p2.getFreeIncident(e, this);
+
+ e.prev.next = freeIncident.next;
+ freeIncident.next.prev = e.prev;
+
+ freeIncident.next = this.next;
+ this.next.prev = freeIncident;
+
+ this.next = e;
+ e.prev = this;
+
+ sync();
+ freeIncident.sync();
+ }
+
+ /** creates an isolated edge out in the middle of space */
public E(P p1, P p2) {
if (p1==p2) throw new Error("attempt to create edge with single vertex: " + p1);
this.p1 = p1;
this.p2 = p2;
+ this.prev = this.next = this.pair = new E(this, this, this);
+ sync();
}
- public int hashCode() { return p1.hashCode() ^ p2.hashCode(); }
- public float length() { return p1.minus(p2).mag(); }
- public boolean equals(Object o) {
- if (o==null || !(o instanceof E)) return false;
- E e = (E)o;
- if (this.p1 == e.p1 && this.p2 == e.p2) return true;
- if (this.p2 == e.p1 && this.p1 == e.p2) return true;
- return false;
+
+ /** adds a new half-edge from prev.p2 to p2 */
+ public E(E prev, P p2) {
+ this.p1 = prev.p2;
+ this.p2 = p2;
+ this.prev = prev;
+ if (p2.getE(p1) != null) throw new Error();
+ if (p2.e==null) {
+ this.next = this.pair = new E(this, this, prev.next);
+ } else {
+ E q = p2.getFreeIncident();
+ this.next = q.next;
+ this.next.prev = this;
+ E z = prev.next;
+ this.prev.next = this;
+ this.pair = new E(q, this, z);
+ }
+ sync();
}
- public P shared(E e) {
- if (p1==e.p1) return p1;
- if (p1==e.p2) return p1;
- if (p2==e.p1) return p2;
- if (p2==e.p2) return p2;
- throw new Error("no shared vertex in shared()");
- }
- public P unshared(E e) {
- if (p1==e.p1) return p2;
- if (p1==e.p2) return p2;
- if (p2==e.p1) return p1;
- if (p2==e.p2) return p1;
- throw new Error("no shared vertex in unshared()");
- }
- public T other(T t) {
- if (t1==t) return t2;
- if (t2==t) return t1;
- throw new Error("edge " + this + " does not own triangle " + t);
- }
- public P other(P p) {
- if (p==p1) return p2;
- if (p==p2) return p1;
- throw new Error("edge " + this + " does not own point " + p);
+
+ /** adds a new half-edge to the mesh with a given predecessor, successor, and pair */
+ public E(E prev, E pair, E next) {
+ this.p1 = prev.p2;
+ this.p2 = next.p1;
+ this.prev = prev;
+ this.next = next;
+ this.pair = pair;
+ sync();
}
+ public P midpoint() { return newP((p1.x+p2.x)/2, (p1.y+p2.y)/2, (p1.z+p2.z)/2); }
+ public boolean has(P p) { return p==p1 || p==p2; }
+ public float length() { return p1.minus(p2).mag(); }
+ public String toString() { return p1+"->"+p2; }
}
/** [UNIQUE] a triangle (face) */
public final class T {
- public final E e1, e2, e3;
- T(E e1, E e2, E e3) {
- if (e1.p1.t==null) e1.p1.t = this;
- if (e1.p2.t==null) e1.p2.t = this;
- if (e2.p1.t==null) e2.p1.t = this;
- if (e2.p2.t==null) e2.p2.t = this;
- if (e3.p1.t==null) e3.p1.t = this;
- if (e3.p2.t==null) e3.p2.t = this;
- if (e1==e2) throw new Error("attempt to create triangle with duplicate edge: " + e1);
- if (e2==e3) throw new Error("attempt to create triangle with duplicate edge: " + e2);
- if (e3==e1) throw new Error("attempt to create triangle with duplicate edge: " + e3);
- // check that each pair of edges shares a vertex
- e1.shared(e2);
- e2.shared(e3);
- e3.shared(e1);
+ public final E e1;
+ public final int color;
+
+ T(E e1) {
this.e1 = e1;
- this.e2 = e2;
- this.e3 = e3;
- // FEATURE: colinearity/sliverness check?
- if (e1.t1 == null) e1.t1 = this; else if (e1.t2 == null) e1.t2 = this; else throw new Error("non-manifold surface");
- if (e2.t1 == null) e2.t1 = this; else if (e2.t2 == null) e2.t2 = this; else throw new Error("non-manifold surface");
- if (e3.t1 == null) e3.t1 = this; else if (e3.t2 == null) e3.t2 = this; else throw new Error("non-manifold surface");
- // FIXME: check that triangles we share an edge with agree on the direction of the normal vector
- // FIXME: check for sealed/watertight surface once construction is complete (an infer normal(s)?)
- }
- public V norm() {
- P p1 = e1.shared(e2);
- P p2 = e2.shared(e3);
- P p3 = e3.shared(e1);
- return p2.minus(p1).cross(p3.minus(p1)).norm();
+ E e2 = e1.next;
+ E e3 = e2.next;
+ if (e1==e2 || e1==e3) throw new Error();
+ if (e3.next!=e1) throw new Error();
+ if (e1.t!=null || e2.t!=null || e3.t!=null)
+ throw new Error("non-manifold surface or disagreeing normals");
+ e1.t = this;
+ e1.next.t = this;
+ e1.next.next.t = this;
+
+ // FIXME: check for sealed/watertight surface once construction is complete (and infer normal(s)?)
+
+ int color = Math.abs(random.nextInt());
+ while(true) {
+ color = color % 4;
+ if (e1().pair.t != null && color == e1().pair.t.color) { color++; continue; }
+ if (e2().pair.t != null && color == e2().pair.t.color) { color++; continue; }
+ if (e3().pair.t != null && color == e3().pair.t.color) { color++; continue; }
+ break;
+ }
+
+ // FIXME unnecssary
+ ts.add(this);
+
+ this.color = color;
}
- public boolean hasE(E e) { return e1==e || e2==e || e3==e; }
+ public P p1() { return e1.p1; }
+ public P p2() { return e1.p2; }
+ public P p3() { return e1.next.p2; }
+ public E e1() { return e1; }
+ public E e2() { return e1.next; }
+ public E e3() { return e1.prev; }
+ public V norm() { return p2().minus(p1()).cross(p3().minus(p1())).norm(); }
+ public boolean hasE(E e) { return e1==e || e1.next==e || e1.prev==e; }
+ public boolean has(P p) { return p1()==p || p2()==p || p3()==p; }
public void glVertices(GL gl) {
p1().glVertex(gl);
p2().glVertex(gl);
p3().glVertex(gl);
}
- public P p1() { return e1.shared(e2); }
- public P p2() { return e1.shared(e3); }
- public P p3() { return e3.shared(e2); }
+
public P centroid() { return newP((p1().x+p2().x+p3().x)/3,
(p1().y+p2().y+p3().y)/3,
(p1().z+p2().z+p3().z)/3); }
public float diameter() {
// FIXME: what is this supposed to be?
- return Math.max(Math.max(e1.length(), e2.length()), e3.length()) / 2;
- }
-
- /** returns the next triangle walking clockwise around the vertex normal */
- public T nextT(P p) { return prevE(p).other(this); }
- public T prevT(P p) { return nextE(p).other(this); }
-
- /** edge "after" this point, moving clockwise around the normal */
- public E nextE(P p) {
- if (p == e1.shared(e2)) return e1;
- else if (p == e2.shared(e3)) return e2;
- else if (p == e3.shared(e1)) return e3;
- else throw new Error("triangle " + this + " does not own point " + p);
+ return Math.max(Math.max(e1().length(), e2().length()), e3().length()) / 2;
}
- /** edge "before" this point, moving clockwise around the normal */
- public E prevE(P p) {
- if (p == e1.shared(e2)) return e2;
- else if (p == e2.shared(e3)) return e3;
- else if (p == e3.shared(e1)) return e1;
- else throw new Error("triangle " + this + " does not own point " + p);
- }
-
- /** returns the angle at point p */
- public double angle(P p) {
- V v1 = firstEdge(p).other(p).minus(p);
- V v2 = secondEdge(p).other(p).minus(p);
- return Math.acos(v1.norm().dot(v2.norm()));
- }
}
+
/** matrix */
public class M {
+ public M() { }
+ public P apply(P p) { return p; }
+ public V apply(V v) { return v; }
+ public M invert() { return this; }
+ public M times(M m) { return this; }
}
}