view layer/LogColourScale.cpp @ 1330:c1f719094c25 zoom

Ensure getFrameForX returns value on zoom blocksize boundary; take advantage of that (this is essentially reverting to the same behaviour as in the default branch, which we should probably have done all along)
author Chris Cannam
date Fri, 21 Sep 2018 11:50:05 +0100
parents a34a2a25907c
children f2525e6cbdf1
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/* -*- 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.
*/

#include "LogColourScale.h"
#include "ColourScaleLayer.h"

#include "base/LogRange.h"

#include <QPainter>

#include <cmath>

#include "LayerGeometryProvider.h"

int
LogColourScale::getWidth(LayerGeometryProvider *,
                            QPainter &paint)
{
    return paint.fontMetrics().width("-000.00") + 15;
}

void
LogColourScale::paintVertical(LayerGeometryProvider *v,
                              const ColourScaleLayer *layer,
                              QPainter &paint,
                              int /* x0 */,
                              double minlog,
                              double maxlog)
{
    int h = v->getPaintHeight();

    int n = 10;

    double val = minlog;
    double inc = (maxlog - val) / n;

    const int buflen = 40;
    char buffer[buflen];

    int boxx = 5, boxy = 5;
    if (layer->getScaleUnits() != "") {
        boxy += paint.fontMetrics().height();
    }
    int boxw = 10, boxh = h - boxy - 5;

    int tx = 5 + boxx + boxw;
    paint.drawRect(boxx, boxy, boxw, boxh);

    paint.save();
    for (int y = 0; y < boxh; ++y) {
        double val = ((boxh - y) * (maxlog - minlog)) / boxh + minlog;
        paint.setPen(layer->getColourForValue(v, LogRange::unmap(val)));
        paint.drawLine(boxx + 1, y + boxy + 1, boxx + boxw, y + boxy + 1);
    }
    paint.restore();

    int dp = 0;
    if (inc > 0) {
        int prec = int(trunc(log10(inc)));
        prec -= 1;
        if (prec < 0) dp = -prec;
    }

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

        int y, ty;

        y = boxy + int(boxh - ((val - minlog) * boxh) / (maxlog - minlog));

        ty = y - paint.fontMetrics().height() +
            paint.fontMetrics().ascent() + 2;

        double dv = LogRange::unmap(val);
        int digits = int(trunc(log10(dv)));
        int sf = dp + (digits > 0 ? digits : 0);
        if (sf < 2) sf = 2;
        snprintf(buffer, buflen, "%.*g", sf, dv);

        QString label = QString(buffer);

        paint.drawLine(boxx + boxw - boxw/3, y, boxx + boxw, y);
        paint.drawText(tx, ty, label);

        val += inc;
    }
}