Remove degenerated tris to reduce render job and avoid artifacts. Patch by hendu.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4524 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/CMeshManipulator.cpp

@@ -916,13 +916,30 @@ IMesh* CMeshManipulator::createMeshWelded(IMesh *mesh, f32 tolerance) const
 			break;
 		}
 
-		// write the buffer's index list
-		core::array<u16> &Indices = *outIdx;
+		// Clean up any degenerate tris
+ 		core::array<u16> &Indices = *outIdx;
+		Indices.clear();
+		Indices.reallocate(indexCount);
+		for (u32 i = 0; i < indexCount; i+=3)
+ 		{
+			u16 a, b, c;
+			a = redirects[indices[i]];
+			b = redirects[indices[i+1]];
+			c = redirects[indices[i+2]];
 
-		Indices.set_used(indexCount);
-		for (u32 i=0; i<indexCount; ++i)
-		{
-			Indices[i] = redirects[ indices[i] ];
+			bool drop = false;
+
+			if (a == b || b == c || a == c)
+				drop = true;
+
+			// Open for other checks
+
+			if (!drop)
+			{
+				Indices.push_back(a);
+				Indices.push_back(b);
+				Indices.push_back(c);
+			}
 		}
 	}
 	return clone;