annotate layer/VerticalBinLayer.h @ 1534:bfd8b22fd67c

Fix #1904 Scrolling colour 3d plot does not always work when in View normalisation mode. We shouldn't imagine we've just invalidated the cache if the truth is that we've only just created the renderer

/* -*- 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 2006-2016 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_BIN_LAYER_H
#define VERTICAL_BIN_LAYER_H

#include "SliceableLayer.h"

/**
 * Interface for layers in which the Y axis corresponds to bin number
 * rather than scale value. Colour3DPlotLayer and SpectrogramLayer are
 * obvious examples.  Conceptually these are always SliceableLayers as
 * well, and this subclasses from SliceableLayer to avoid a big
 * inheritance mess.
 */
class VerticalBinLayer : public SliceableLayer
{
public:
    /**
     * Return the y coordinate at which the given bin "starts"
     * (i.e. at the bottom of the bin, if the given bin is an integer
     * and the vertical scale is the usual way up). Bin number may be
     * fractional, to obtain a position part-way through a bin.
     */
    virtual double getYForBin(const LayerGeometryProvider *, double bin) const = 0;

    /**
     * As getYForBin, but rounding to integer values.
     */
    virtual int getIYForBin(const LayerGeometryProvider *v, int bin) const {
        return int(round(getYForBin(v, bin)));
    }
    
    /**
     * Return the bin number, possibly fractional, at the given y
     * coordinate. Note that the whole numbers occur at the positions
     * at which the bins "start" (i.e. the bottom of the visible bin,
     * if the vertical scale is the usual way up).
     */
    virtual double getBinForY(const LayerGeometryProvider *, double y) const = 0;

    /**
     * As getBinForY, but rounding to integer values.
     */
    virtual int getIBinForY(const LayerGeometryProvider *v, int y) const {
        return int(floor(getBinForY(v, y)));
    }
};

#endif