X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=flower%2Finclude%2Foffset.hh;h=ccf64ea784e172007a99c10a63888461b852542d;hb=15af6574b4ad5c382867f76cbd3938fde1cc10db;hp=b7fea1313abe0909026ccc12693e41c7bb592afb;hpb=da66c77772050eccbb972538c2cf9f6ec76018b4;p=lilypond.git

diff --git a/flower/include/offset.hh b/flower/include/offset.hh
index b7fea1313a..ccf64ea784 100644
--- a/flower/include/offset.hh
+++ b/flower/include/offset.hh
@@ -11,16 +11,19 @@
 #include "real.hh"
 #include "axes.hh"
 #include "arithmetic-operator.hh"
+#include "string.hh"
 
 Offset complex_multiply (Offset, Offset);
 Offset complex_divide (Offset, Offset);
 Offset complex_exp (Offset);
 
 
-/** 2d vector
-    should change to Complex -- how is vector == complex?
+/*
+
+This is a mixture a 2D vector. Sometimes it can
+also be convenient to think of 2D vectors as complex numbers
+(ie. x + i y). The naming of some methods reflects that.
 
-    ughr wat een beerput
 */
 class Offset 
 {
@@ -96,13 +99,12 @@ public:
     return *this;
   }
   
-  Real  arg () const;
+  Real arg () const;
   Real length () const;
 
-  //wtf, How is Offset a Complex? is this used?
   Offset operator *= (Offset z2) 
   {
-    *this = complex_multiply (*this,z2);
+    *this = complex_multiply (*this, z2);
     return *this;
   }
 
@@ -133,6 +135,13 @@ mirror (Offset o, Axis a)
   return o;
 }
 
+inline
+Real
+dot_product  (Offset o1, Offset o2)
+{
+  return o1[X_AXIS] * o2[X_AXIS] + o1[Y_AXIS] * o2[Y_AXIS];
+}
+
 
 #endif /* OFFSET_HH */