better error checking in Mesh.java

diff --git a/src/edu/berkeley/qfat/Mesh.java b/src/edu/berkeley/qfat/Mesh.java
index 032457b..2e68c17 100644 (file)
--- a/src/edu/berkeley/qfat/Mesh.java
+++ b/src/edu/berkeley/qfat/Mesh.java
@@ -971,8 +971,11 @@ public class Mesh implements Iterable<Mesh.T> {
     }
     public T newT(Point v1, Point v2, Point v3, Vec norm) { return newT(v1, v2, v3, norm, 1); }
     public T newT(Point v1, Point v2, Point v3, Vec norm, int colorclass) {
     }
     public T newT(Point v1, Point v2, Point v3, Vec norm) { return newT(v1, v2, v3, norm, 1); }
     public T newT(Point v1, Point v2, Point v3, Vec norm, int colorclass) {

+        if (v1.equals(v2)
+            || v2.equals(v3)
+            || v3.equals(v1))
+            throw new Error("attempt to make a triangle with a length-zero side");

         if (coalesce) {
         if (coalesce) {

-

             for(Vertex v : vertices) { if (v1.distance(v.p) < EPSILON) { v1 = v.p; break; } }
             for(Vertex v : vertices) { if (v2.distance(v.p) < EPSILON) { v2 = v.p; break; } }
             for(Vertex v : vertices) { if (v3.distance(v.p) < EPSILON) { v3 = v.p; break; } }
             for(Vertex v : vertices) { if (v1.distance(v.p) < EPSILON) { v1 = v.p; break; } }
             for(Vertex v : vertices) { if (v2.distance(v.p) < EPSILON) { v2 = v.p; break; } }
             for(Vertex v : vertices) { if (v3.distance(v.p) < EPSILON) { v3 = v.p; break; } }

@@ -981,6 +984,11 @@ public class Mesh implements Iterable<Mesh.T> {
             v2 = new Point(round(v2.x), round(v2.y), round(v2.z));
             v3 = new Point(round(v3.x), round(v3.y), round(v3.z));
             */
             v2 = new Point(round(v2.x), round(v2.y), round(v2.z));
             v3 = new Point(round(v3.x), round(v3.y), round(v3.z));
             */

+            /*
+            // triangle's vertices got merged
+            if (v1.equals(v2) || v2.equals(v3) || v3.equals(v1))
+                return null;
+            */

         }
         if (norm != null) {
             Vec norm2 = v3.minus(v1).cross(v2.minus(v1));
         }
         if (norm != null) {
             Vec norm2 = v3.minus(v1).cross(v2.minus(v1));

@@ -991,6 +999,7 @@ public class Mesh implements Iterable<Mesh.T> {
         E e12 = makeE(v1, v2);
         E e23 = makeE(v2, v3);
         E e31 = makeE(v3, v1);
         E e12 = makeE(v1, v2);
         E e23 = makeE(v2, v3);
         E e31 = makeE(v3, v1);

+        if (e12==e23 || e23==e31 || e12==e31) throw new Error();

         while(e12.next != e23 || e23.next != e31 || e31.next != e12) {
             e12.makeAdjacent(e23);
             e23.makeAdjacent(e31);
         while(e12.next != e23 || e23.next != e31 || e31.next != e12) {
             e12.makeAdjacent(e23);
             e23.makeAdjacent(e31);