Avoid some unnecessary redrawing.

VU_Meter.C

@@ -18,7 +18,7 @@
 /*******************************************************************************/
 
 /* a VU meter, either horizontal or vertical.  Color is a gradient
-   from color() to selection_color(). box() is used to draw the
+   from min_color() to max_color(). box() is used to draw the
    individual 'lights'. division() controls how many 'lights' there
    are. */
 
@@ -53,9 +53,8 @@ void
 VU_Meter::draw ( void )
 {
 //    draw_box( FL_FLAT_BOX, x(), y(), w(), h(), color() );
-
-    int v = (value() / maximum()) * _divisions;
-    int pv = (_peak / maximum()) * _divisions;
+    int v = pos( value() );
+    int pv = pos( _peak );
 
     int bh = h() / _divisions;
     int bw = w() / _divisions;

VU_Meter.H

@@ -37,6 +37,8 @@ class VU_Meter : public Fl_Widget
     Fl_Color _min_color;
     Fl_Color _max_color;
 
+    int pos ( float v ) { return ( v / _maximum ) * _divisions; }
+
 protected:
 
     virtual void draw ( void );
@@ -52,7 +54,7 @@ public:
     void minimum ( float v ) { _minimum = v; redraw(); }
     float minimum ( void ) const { return _minimum; }
 
-    void value ( float v ) { _value = v; redraw(); }
+    void value ( float v ) { if ( pos( v ) != pos( _value ) ) redraw();  _value = v; }
     float value ( void ) const { return _value; }
 
     void reset ( void ) { _peak = 0.0f; }