add some documentation for glseqbrowser::viewport*

diff --git a/alg/glseqbrowser.hpp b/alg/glseqbrowser.hpp
index a662010161c46ae089495b4397ffe01a2333085b..5a6638d5049fb2552961b892ec5a9db796d00668 100644 (file)
--- a/alg/glseqbrowser.hpp
+++ b/alg/glseqbrowser.hpp
@@ -35,10 +35,15 @@ public:
   float right() const;
 
   void setViewportCenter(float x);
+  //! return world coordinate of the left side of the viewport
   float viewportLeft() const;
+  //! return world coordinate of the center of the viewport
   float viewportCenter() const;
+  //! return world coordinate of the right side of the viewport
   float viewportRight() const;
+  //! return height of the viewport in world coordinates
   float viewportHeight() const;
+  //! return width of the viewport in world coordinates
   float viewportWidth() const;
 
   //! zoom out far enough to show the full size of the sequence
@@ -49,7 +54,7 @@ public:
   /*! its a double as zoom levels of [0.01, 1.0] make nice sequence views
    */
   void setZoom(double zoom_level);
-  //! returns the current zoom level
+  //! returns the current zoom level as basepairs per pixel
   double zoom() const;
 
   void setColorMapper(AnnotationColors& cm);