checkpoint

darcs-hash:20071126042534-5007d-e179bb755aca414a3109ae51aa21dac8b5ac86b6.gz

diff --git a/src/Geom.java b/src/Geom.java
index c879bfe..944ee61 100644 (file)
--- a/src/Geom.java
+++ b/src/Geom.java
@@ -5,20 +5,42 @@ import javax.swing.*;
 import javax.media.opengl.*;
 import javax.media.opengl.glu.*;
 
-public class Geom {
+public class Geom implements Iterable<Geom.T> {
 
     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(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);
+        ps.put(p,p);
         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;
+    }
+
+    public T newT(E e1, E e2, E e3) {
+        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;
+        return new T(e1, e2, e3);
+    }
 
     /** point in 3-space */
-    public class P {
+    public final class P {
         public final float x, y, z;
         public P(float x, float y, float z) { this.x = x; this.y = y; this.z = z; }
         public V minus(P p) { return null; }
@@ -33,10 +55,11 @@ public class Geom {
                 Float.floatToIntBits(y) ^
                 Float.floatToIntBits(z);
         }
+        public void glVertex(GL gl) { gl.glVertex3f(x, y, z); }
     }
 
     /** vector in 3-space */
-    public class V {
+    public final class V {
         private final float x, y, z;
         public V(float x, float y, float z) { this.x = x; this.y = y; this.z = z; }
         public V norm() { return null; /* FIXME */ }
@@ -45,10 +68,11 @@ public class Geom {
     }
 
     /** an edge */
-    public class E {
+    public final class E {
         public final P p1, p2;
-        private T t1, t2;
+        T t1, t2;
         public E(P p1, P p2) { this.p1 = p1; this.p2 = p2; }
+        public int hashCode() { return p1.hashCode() ^ p2.hashCode(); }
         public boolean equals(Object o) {
             if (o==null || !(o instanceof E)) return false;
             E e = (E)o;
@@ -56,11 +80,24 @@ public class Geom {
             if (this.p2 == e.p1 && this.p1 == e.p2) return true;
             return false;
         }
-        public P shared(E e) { return null; }
+        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()");
+        }
     }
 
     /** a triangle (face) */
-    public class T {
+    public final class T {
         public final E e1, e2, e3;
         public T(E e1, E e2, E e3, V normal) {
             P p1 = e1.shared(e2);
@@ -76,6 +113,10 @@ public class Geom {
                 this.e2 = e2;
                 this.e3 = e1;
             }
+            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");
+            ts.add(this);
         }
         public V norm() {
             P p1 = e1.shared(e2);
@@ -83,7 +124,34 @@ public class Geom {
             P p3 = e3.shared(e1);
             return p2.minus(p1).cross(p3.minus(p1)).norm();
         }
-        public T(E e1, E e2, E e3) { this.e1 = e1; this.e2 = e2; this.e3 = e3; }
+        public T(E e1, E e2, E e3) {
+            this.e1 = e1;
+            this.e2 = e2;
+            this.e3 = e3;
+            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");
+            ts.add(this);
+        }
+        public boolean hasE(E e) { return e1==e || e2==e || e3==e; }
+
+        // technically not required
+        /*
+        public int hashCode() { return e1.hashCode() ^ e2.hashCode() ^ e3.hashCode(); }
+        public boolean equals(Object o) {
+            if (o==null || !(o instanceof T)) return false;
+            T t = (T)o;
+            if (this.e1 == t.e1 && this.e2 == t.e2 && this.e3 == t.e3) return true;
+            if (this.e1 == t.e2 && this.e2 == t.e3 && this.e3 == t.e1) return true;
+            if (this.e1 == t.e3 && this.e2 == t.e1 && this.e3 == t.e2) return true;
+            return false;
+        }
+        */
+        public void glVertices(GL gl) {
+            e1.unshared(e2).glVertex(gl);
+            e1.shared(e2).glVertex(gl);
+            e2.shared(e3).glVertex(gl);
+        }
     }
 
     /** matrix */

diff --git a/src/Main.java b/src/Main.java
index 1e496ea..64852c9 100644 (file)
--- a/src/Main.java
+++ b/src/Main.java
@@ -6,7 +6,24 @@ import javax.media.opengl.glu.*;
 
 public class Main implements GLEventListener {
 
-    public static StlFile stlf = null;
+    private Geom geom = new Geom();
+
+    public Main(StlFile stlf) {
+        for(int i=0; i<stlf.coordArray.length; i+=3) {
+            Geom.P p0 = geom.newP(stlf.coordArray[i+0].x,
+                                  stlf.coordArray[i+0].y,
+                                  stlf.coordArray[i+0].z);
+            Geom.P p1 = geom.newP(stlf.coordArray[i+1].x,
+                                  stlf.coordArray[i+1].y,
+                                  stlf.coordArray[i+1].z);
+            Geom.P p2 = geom.newP(stlf.coordArray[i+2].x,
+                                  stlf.coordArray[i+2].y,
+                                  stlf.coordArray[i+2].z);
+            Geom.T t = geom.newT(geom.newE(p0, p1),
+                                 geom.newE(p1, p2),
+                                 geom.newE(p2, p0));
+        }
+    }
 
     /**
      * Take care of initialization here.
@@ -33,7 +50,7 @@ public class Main implements GLEventListener {
         gl.glClear(GL.GL_COLOR_BUFFER_BIT);
         gl.glPointSize(5.0f);
 
-        for(int i=0; i<stlf.coordArray.length; i+=3) {
+        for(Geom.T t : geom) {
             red -= .09f;
             green -= .12f;
             blue -= .15f;
@@ -41,12 +58,8 @@ public class Main implements GLEventListener {
             if (green < 0.15) green = 1.0f;
             if (blue < 0.15) blue = 1.0f;
             gl.glColor3f(red, green, blue);
-
             gl.glBegin(GL.GL_TRIANGLES);
-            for(int j=0; j<3; j++)
-                gl.glVertex3f(stlf.coordArray[i+j].x,
-                              stlf.coordArray[i+j].y,
-                              stlf.coordArray[i+j].z);
+            t.glVertices(gl);
             gl.glEnd();
         }
     }
@@ -55,19 +68,9 @@ public class Main implements GLEventListener {
 
 
     public static void main(String[] s) throws Exception {
-        stlf = new StlFile();
+        StlFile stlf = new StlFile();
         stlf.load("teapot.stl");
-
-        Main main = new Main();
-
-        Geom geom = new Geom();
-        for(int i=0; i<stlf.coordArray.length; i+=3) {
-            for(int j=0; j<3; j++)
-                geom.newP(stlf.coordArray[i+j].x,
-                          stlf.coordArray[i+j].y,
-                          stlf.coordArray[i+j].z);
-        }
-
+        Main main = new Main(stlf);
         Frame f = new Frame();
         GLCapabilities glcaps = new GLCapabilities();
         GLCanvas glcanvas = new GLCanvas();