comparison layer/SpectrogramLayer.h @ 477:92f4d88241b8

* some preparatory reorganisation

         QColor m_colours[256];
     };
 
     Palette m_palette;
 
+    /**
+     * PixmapCache covers the area of the view, at view resolution.
+     * Not all of it is necessarily valid at once (it is refreshed
+     * in parts when scrolling, for example).
+     */
     struct PixmapCache
     {
         QPixmap pixmap;
         QRect validArea;
         long startFrame;

     };
     typedef std::map<const View *, PixmapCache> ViewPixmapCache;
     void invalidatePixmapCaches();
     void invalidatePixmapCaches(size_t startFrame, size_t endFrame);
     mutable ViewPixmapCache m_pixmapCaches;
+
+    /**
+     * When painting, we draw directly onto the draw buffer and then
+     * copy this to the part of the pixmap cache that needed refreshing
+     * before copying the pixmap cache onto the window.  (Remind me why
+     * we don't draw directly onto the cache?)
+     */
     mutable QImage m_drawBuffer;
 
     mutable QTimer *m_updateTimer;
 
     mutable size_t m_candidateFillStartFrame;

     typedef std::map<const View *, MagnitudeRange> ViewMagMap;
     mutable ViewMagMap m_viewMags;
     mutable std::vector<MagnitudeRange> m_columnMags;
     void invalidateMagnitudes();
     bool updateViewMagnitudes(View *v) const;
+    bool getColumnValues(View *v, FFTModel *fft, int x0, int x,
+                         int minbin, int maxbin,
+                         float displayMinFreq, float displayMaxFreq,
+                         const int h,
+                         const float *yforbin, float *yval) const;
 
     virtual void updateMeasureRectYCoords(View *v, const MeasureRect &r) const;
     virtual void setMeasureRectYCoord(View *v, MeasureRect &r, bool start, int y) const;
 };