Fix a couple of float/double issues.

Author: speps

LibTessDotNet/Sources/MeshUtils.cs

@@ -90,7 +90,7 @@ public static void Normalize(ref Vec3 v)
         {
             var len = v.X * v.X + v.Y * v.Y + v.Z * v.Z;
             Debug.Assert(len >= 0.0f);
-            len = 1.0f / (float)Math.Sqrt(len);
+            len = 1.0f / (Real)Math.Sqrt(len);
             v.X *= len;
             v.Y *= len;
             v.Z *= len;

LibTessDotNet/Sources/Tess.cs

@@ -104,7 +104,11 @@ public partial class Tess
 
         public Real SUnitX = 1;
         public Real SUnitY = 0;
+#if DOUBLE
+        public Real SentinelCoord = 4e150;
+#else
         public Real SentinelCoord = 4e30f;
+#endif
 
         /// <summary>
         /// If true, will remove empty (zero area) polygons.
@@ -471,7 +475,7 @@ private void OutputPolymesh(ElementType elementType, int polySize)
                 if (NoEmptyPolygons)
                 {
                     var area = MeshUtils.FaceArea(f);
-                    if (Math.Abs(area) < float.Epsilon)
+                    if (Math.Abs(area) < Real.Epsilon)
                     {
                         continue;
                     }
@@ -525,7 +529,7 @@ private void OutputPolymesh(ElementType elementType, int polySize)
                 if (NoEmptyPolygons)
                 {
                     var area = MeshUtils.FaceArea(f);
-                    if (Math.Abs(area) < float.Epsilon)
+                    if (Math.Abs(area) < Real.Epsilon)
                     {
                         continue;
                     }