comparison layer/PianoScale.h @ 1238:4d0ca1ab4cd0

Some work to make spectrum layers (and slice layers generally) zoomable in the frequency axis. Also fixes a number of view id mixups in SliceLayer which broke offset calculations for the x axis scale.

 class PianoScale
 {
 public:
     void paintPianoVertical
     (LayerGeometryProvider *v, QPainter &paint, QRect rect, double minf, double maxf);
+
+    class HorizontalScaleProvider {
+    public:
+        virtual double getFrequencyForX(const LayerGeometryProvider *, double x) const = 0;
+        virtual double getXForFrequency(const LayerGeometryProvider *, double freq) const = 0;
+    };
+    
+    void paintPianoHorizontal
+    (LayerGeometryProvider *v, const HorizontalScaleProvider *p,
+     QPainter &paint, QRect rect);
 };
 
 #endif