diff --git a/coresdk/src/coresdk/clipping.cpp b/coresdk/src/coresdk/clipping.cpp
index dbe480fa..73c011b4 100644
--- a/coresdk/src/coresdk/clipping.cpp
+++ b/coresdk/src/coresdk/clipping.cpp
@@ -53,7 +53,6 @@ namespace splashkit_lib
             LOG(WARNING) << "Attempting to push clip rect to invalid window";
             return;
         }
-
         _push_clip(wnd->image, r);
     }
 
@@ -119,7 +118,7 @@ namespace splashkit_lib
 
         if ( img.clip_stack.size() > 0 )
         {
-            rectangle clip_rect = *img.clip_stack.end();
+            rectangle clip_rect = img.clip_stack.back();
             sk_set_clip_rect(&img.surface, clip_rect.x, clip_rect.y, clip_rect.width, clip_rect.height);
         }
         else
@@ -158,7 +157,7 @@ namespace splashkit_lib
     rectangle _current_clip(const image_data &img)
     {
         if (img.clip_stack.size() > 0)
-            return *img.clip_stack.end();
+            return img.clip_stack.back();
         else
             return rectangle_from(0, 0, img.surface.width, img.surface.height);
     }
diff --git a/coresdk/src/coresdk/point_geometry.cpp b/coresdk/src/coresdk/point_geometry.cpp
index 04a5b2e1..06096b2a 100644
--- a/coresdk/src/coresdk/point_geometry.cpp
+++ b/coresdk/src/coresdk/point_geometry.cpp
@@ -107,7 +107,7 @@ namespace splashkit_lib
         v = (dot00 * dot12 - dot01 * dot02) * inv_denom;
 
         // Check if point is in triangle
-        return ((u > 0.0) and (v > 0.0) and (u + v < 1.0));
+        return ((u >= 0) and (v >= 0) and (u + v <= 1));
     }
 
     bool point_in_rectangle(const point_2d &pt, const rectangle &rect)
diff --git a/coresdk/src/coresdk/vector_2d.cpp b/coresdk/src/coresdk/vector_2d.cpp
index 930cfea5..6ba31bc6 100644
--- a/coresdk/src/coresdk/vector_2d.cpp
+++ b/coresdk/src/coresdk/vector_2d.cpp
@@ -116,7 +116,9 @@ namespace splashkit_lib
 
     double angle_between(const vector_2d &v1, const vector_2d &v2)
     {
-        return vector_angle( vector_subtract(v2, v1) );
+        double dot = dot_product(v1, v2);
+        double det = v1.x * v2.y - v1.y * v2.x;
+        return rad_to_deg(atan2(det, dot));
     }
 
     vector_2d vector_normal(const vector_2d &v)