annotate layer/VerticalScaleLayer.h @ 1541:b4b5b8dd5fe1

Fix getScaleProvidingLayerForUnit to make it only return a layer that actually has display extents. Modify getVisibleExtentsForUnit to make it more like the behaviour in 3.x: where no layer with display extents is found, use the union of the value extents of layers with the right unit. Partial fix for #1954 Peculiar alignment for Amplitude Follower y-scale in Auto-Align mode.

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006-2013 Chris Cannam and QMUL.
    
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef VERTICAL_SCALE_LAYER_H
#define VERTICAL_SCALE_LAYER_H

/**
 * Interface for layers in which the Y axis represents (or can
 * sometimes represent, depending on the display mode) the sample
 * value. For example, TimeValueLayer uses vertical scale when in
 * point mode and so provides this interface.
 */
class VerticalScaleLayer
{
public:
    virtual int getYForValue(LayerGeometryProvider *, double value) const = 0;
    virtual double getValueForY(LayerGeometryProvider *, int y) const = 0;
    virtual QString getScaleUnits() const = 0;
};

#endif