library: disallow GImpact shapes with zero triangles

stephengold · Sep 12, 2024 · d59d424 · d59d424
1 parent 6a4d135
commit d59d424
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Showing 2 changed files with 30 additions and 9 deletions.
diff --git a/MinieLibrary/src/main/java/com/jme3/bullet/collision/shapes/GImpactCollisionShape.java b/MinieLibrary/src/main/java/com/jme3/bullet/collision/shapes/GImpactCollisionShape.java
@@ -87,36 +87,46 @@ protected GImpactCollisionShape() {
     /**
      * Instantiate a shape based on the specified CompoundMesh and offset.
      *
-     * @param mesh the mesh on which to base the shape (not null, unaffected)
+     * @param mesh the mesh on which to base the shape (not null, must contain
+     * at least one triangle, unaffected)
      * @param offset the offset to add to the vertex positions (not null,
      * unaffected)
      */
     public GImpactCollisionShape(CompoundMesh mesh, Vector3f offset) {
+        Validate.require(mesh.countTriangles() > 0, "at least one triangle");
+
         this.nativeMesh = new CompoundMesh(mesh, offset);
         createShape();
     }
 
     /**
      * Instantiate a shape based on the specified native mesh(es).
      *
-     * @param submeshes the mesh(es) on which to base the shape (not null)
+     * @param submeshes the mesh(es) on which to base the shape (not null, must
+     * contain at least one triangle)
      */
     public GImpactCollisionShape(IndexedMesh... submeshes) {
         this.nativeMesh = new CompoundMesh();
         for (IndexedMesh submesh : submeshes) {
             nativeMesh.add(submesh);
         }
+        Validate.require(
+                nativeMesh.countTriangles() > 0, "at least one triangle");
+
         createShape();
     }
 
     /**
      * Instantiate a shape based on the specified JME mesh(es).
      *
-     * @param jmeMeshes the mesh(es) on which to base the shape (not null,
-     * unaffected)
+     * @param jmeMeshes the mesh(es) on which to base the shape (not null, must
+     * contain at least one triangle, unaffected)
      */
     public GImpactCollisionShape(Mesh... jmeMeshes) {
         this.nativeMesh = new CompoundMesh(jmeMeshes);
+        Validate.require(
+                nativeMesh.countTriangles() > 0, "at least one triangle");
+
         createShape();
     }
     // *************************************************************************
@@ -303,6 +313,9 @@ public void write(JmeExporter exporter) throws IOException {
      * Instantiate the configured {@code btGImpactMeshShape}.
      */
     private void createShape() {
+        int numTriangles = nativeMesh.countTriangles();
+        assert numTriangles > 0 : numTriangles;
+
         long meshId = nativeMesh.nativeId();
         long shapeId = createShape(meshId);
         setNativeId(shapeId);

diff --git a/MinieLibrary/src/test/java/jme3utilities/minie/test/TestEmptyShape.java b/MinieLibrary/src/test/java/jme3utilities/minie/test/TestEmptyShape.java
@@ -95,13 +95,21 @@ public void testEmptyShape() {
         shape = new CompoundCollisionShape();
         rigidBody = new PhysicsRigidBody(shape, PhysicsBody.massForStatic);
 
-        shape = new GImpactCollisionShape(indexedMeshArray);
-        rigidBody = new PhysicsRigidBody(shape, PhysicsBody.massForStatic);
+        // Attempt to create empty shapes in various illegal ways.
+        try {
+            shape = new GImpactCollisionShape(indexedMeshArray);
+            Assert.fail("Expected an IllegalArgumentException");
+        } catch (IllegalArgumentException exception) {
+            // do nothing
+        }
 
-        shape = new GImpactCollisionShape(jmeMeshArray);
-        rigidBody = new PhysicsRigidBody(shape, PhysicsBody.massForStatic);
+        try {
+            shape = new GImpactCollisionShape(jmeMeshArray);
+            Assert.fail("Expected an IllegalArgumentException");
+        } catch (IllegalArgumentException exception) {
+            // do nothing
+        }
 
-        // Attempt to create empty shapes in various illegal ways.
         try {
             shape = new HeightfieldCollisionShape(floatArray);
             Assert.fail("Expected an IllegalArgumentException");