view layer/LogNumericalScale.cpp @ 1386:fc3d89f88690 spectrogramparam

Use log-frequency rather than log-bin for calculating x coord in spectrum. This has the advantage that frequency positions don't move when we change the window size or oversampling ratio, but it does give us an unhelpfully large amount of space for very low frequencies - to be considered

/* -*- 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 2006-2018 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.
*/

#include "LogNumericalScale.h"
#include "VerticalScaleLayer.h"
#include "LayerGeometryProvider.h"

#include "base/LogRange.h"
#include "base/ScaleTickIntervals.h"

#include <QPainter>

#include <cmath>

int
LogNumericalScale::getWidth(LayerGeometryProvider *,
                            QPainter &paint)
{
    return paint.fontMetrics().width("-000.00") + 10;
}

void
LogNumericalScale::paintVertical(LayerGeometryProvider *v,
                                 const VerticalScaleLayer *layer,
                                 QPainter &paint,
                                 int x0,
                                 double minlog,
                                 double maxlog)
{
    int n = 10;
    auto ticks = ScaleTickIntervals::logarithmicAlready({ minlog, maxlog, n });
    n = int(ticks.size());

    int w = getWidth(v, paint) + x0;

    int prevy = -1;
                
    for (int i = 0; i < n; ++i) {

        int y, ty;
        bool drawText = true;

        if (i == n-1 &&
            v->getPaintHeight() < paint.fontMetrics().height() * (n*2)) {
            if (layer->getScaleUnits() != "") drawText = false;
        }

        double val = ticks[i].value;
        QString label = QString::fromStdString(ticks[i].label);

        y = layer->getYForValue(v, val);

        ty = y - paint.fontMetrics().height() + paint.fontMetrics().ascent() + 2;
        
        if (prevy >= 0 && (prevy - y) < paint.fontMetrics().height()) {
            continue;
        }

        paint.drawLine(w - 5, y, w, y);

        if (drawText) {
            paint.drawText(w - paint.fontMetrics().width(label) - 6,
                           ty, label);
        }

        prevy = y;
    }
}