fix brush projection to eliminate seams, still problems with big brushes and need to implement erase

engine/node.h

@@ -138,9 +138,6 @@ public:
     float GetHeight();
     glm::vec2 GetSize();
 
-    glm::vec4 rect_intersection(glm::vec4 a, glm::vec4 b) const;
-    glm::vec4 rect_union(glm::vec4 a, glm::vec4 b) const;
-
     virtual void restore_context();;
     virtual void clear_context();
     void update(float width, float height, float zoom);