view layer/ColourMapper.cpp @ 1127:9fb8dfd7ce4c spectrogram-minor-refactor

Fix threshold in spectrogram -- it wasn't working in the last release.
There is a new protocol for this. Formerly the threshold parameter had a
range from -50dB to 0 with the default at -50, and -50 treated internally
as "no threshold". However, there was a hardcoded, hidden internal threshold
for spectrogram colour mapping at -80dB with anything below this being rounded
to zero. Now the threshold parameter has range -81 to -1 with the default
at -80, -81 is treated internally as "no threshold", and there is no hidden
internal threshold. So the default behaviour is the same as before, an
effective -80dB threshold, but it is now possible to change this in both
directions. Sessions reloaded from prior versions may look slightly different
because, if the session says there should be no threshold, there will now
actually be no threshold instead of having the hidden internal one.

Still need to do something in the UI to make it apparent that the -81dB
setting removes the threshold entirely. This is at least no worse than the
previous, also obscured, magic -50dB setting.

/* -*- 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 2006-2007 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 "ColourMapper.h"

#include <iostream>

#include <cmath>

#include "base/Debug.h"

#include <vector>

using namespace std;

static vector<QColor> convertStrings(const vector<QString> &strs)
{
    vector<QColor> converted;
    for (const auto &s: strs) converted.push_back(QColor(s));
    reverse(converted.begin(), converted.end());
    return converted;
}

static vector<QColor> ice = convertStrings({
        // Based on ColorBrewer ylGnBu
        "#ffffff", "#ffff00", "#f7fcf0", "#e0f3db", "#ccebc5", "#a8ddb5",
        "#7bccc4", "#4eb3d3", "#2b8cbe", "#0868ac", "#084081", "#042040"
        });

static vector<QColor> cherry = convertStrings({
        "#f7f7f7", "#fddbc7", "#f4a582", "#d6604d", "#b2182b", "#dd3497",
        "#ae017e", "#7a0177", "#49006a"
        });
    
static void
mapDiscrete(double norm, vector<QColor> &colours, double &r, double &g, double &b)
{
    int n = int(colours.size());
    double m = norm * (n-1);
    if (m >= n-1) { colours[n-1].getRgbF(&r, &g, &b, 0); return; }
    if (m <= 0) { colours[0].getRgbF(&r, &g, &b, 0); return; }
    int base(int(floor(m)));
    double prop0 = (base + 1.0) - m, prop1 = m - base;
    QColor c0(colours[base]), c1(colours[base+1]);
    r = c0.redF() * prop0 + c1.redF() * prop1;
    g = c0.greenF() * prop0 + c1.greenF() * prop1;
    b = c0.blueF() * prop0 + c1.blueF() * prop1;
}

ColourMapper::ColourMapper(int map, double min, double max) :
    m_map(map),
    m_min(min),
    m_max(max)
{
    if (m_min == m_max) {
        cerr << "WARNING: ColourMapper: min == max (== " << m_min
                  << "), adjusting" << endl;
        m_max = m_min + 1;
    }
}

ColourMapper::~ColourMapper()
{
}

int
ColourMapper::getColourMapCount()
{
    return 12;
}

QString
ColourMapper::getColourMapName(int n)
{
    if (n >= getColourMapCount()) return QObject::tr("<unknown>");
    StandardMap map = (StandardMap)n;

    switch (map) {
    case Green:            return QObject::tr("Green");
    case WhiteOnBlack:     return QObject::tr("White on Black");
    case BlackOnWhite:     return QObject::tr("Black on White");
    case Cherry:           return QObject::tr("Cherry");
    case Wasp:             return QObject::tr("Wasp");
    case Ice:              return QObject::tr("Ice");
    case Sunset:           return QObject::tr("Sunset");
    case FruitSalad:       return QObject::tr("Fruit Salad");
    case Banded:           return QObject::tr("Banded");
    case Highlight:        return QObject::tr("Highlight");
    case Printer:          return QObject::tr("Printer");
    case HighGain:         return QObject::tr("High Gain");
    }

    return QObject::tr("<unknown>");
}

QColor
ColourMapper::map(double value) const
{
    double norm = (value - m_min) / (m_max - m_min);
    if (norm < 0.0) norm = 0.0;
    if (norm > 1.0) norm = 1.0;
    
    double h = 0.0, s = 0.0, v = 0.0, r = 0.0, g = 0.0, b = 0.0;
    bool hsv = true;

    double blue = 0.6666, pieslice = 0.3333;

    if (m_map >= getColourMapCount()) return Qt::black;
    StandardMap map = (StandardMap)m_map;

    switch (map) {

    case Green:
        h = blue - norm * 2.0 * pieslice;
        s = 0.5f + norm/2.0;
        v = norm;
        break;

    case WhiteOnBlack:
        r = g = b = norm;
        hsv = false;
        break;

    case BlackOnWhite:
        r = g = b = 1.0 - norm;
        hsv = false;
        break;

    case Cherry:
        hsv = false;
        mapDiscrete(norm, cherry, r, g, b);
        break;

    case Wasp:
        h = 0.15;
        s = 1.0;
        v = norm;
        break;

    case Sunset:
        r = (norm - 0.24) * 2.38;
        if (r > 1.0) r = 1.0;
        if (r < 0.0) r = 0.0;
        g = (norm - 0.64) * 2.777;
        if (g > 1.0) g = 1.0;
        if (g < 0.0) g = 0.0;
        b = (3.6f * norm);
        if (norm > 0.277) b = 2.0 - b;
        if (b > 1.0) b = 1.0;
        if (b < 0.0) b = 0.0;
        hsv = false;
        break;

    case FruitSalad:
        h = blue + (pieslice/6.0) - norm;
        if (h < 0.0) h += 1.0;
        s = 1.0;
        v = 1.0;
        break;

    case Banded:
        if      (norm < 0.125) return Qt::darkGreen;
        else if (norm < 0.25)  return Qt::green;
        else if (norm < 0.375) return Qt::darkBlue;
        else if (norm < 0.5)   return Qt::blue;
        else if (norm < 0.625) return Qt::darkYellow;
        else if (norm < 0.75)  return Qt::yellow;
        else if (norm < 0.875) return Qt::darkRed;
        else                   return Qt::red;
        break;

    case Highlight:
        if (norm > 0.99) return Qt::white;
        else return Qt::darkBlue;

    case Printer:
        if (norm > 0.8) {
            r = 1.0;
        } else if (norm > 0.7) {
            r = 0.9;
        } else if (norm > 0.6) {
            r = 0.8;
        } else if (norm > 0.5) {
            r = 0.7;
        } else if (norm > 0.4) {
            r = 0.6;
        } else if (norm > 0.3) {
            r = 0.5;
        } else if (norm > 0.2) {
            r = 0.4;
        } else {
            r = 0.0;
        }
        r = g = b = 1.0 - r;
        hsv = false;
        break;

    case HighGain:
        if (norm <= 1.0 / 256.0) {
            norm = 0.0;
        } else {
            norm = 0.1f + (pow(((norm - 0.5) * 2.0), 3.0) + 1.0) / 2.081;
        }
        // now as for Sunset
        r = (norm - 0.24) * 2.38;
        if (r > 1.0) r = 1.0;
        if (r < 0.0) r = 0.0;
        g = (norm - 0.64) * 2.777;
        if (g > 1.0) g = 1.0;
        if (g < 0.0) g = 0.0;
        b = (3.6f * norm);
        if (norm > 0.277) b = 2.0 - b;
        if (b > 1.0) b = 1.0;
        if (b < 0.0) b = 0.0;
        hsv = false;
/*
        if (r > 1.0) r = 1.0;
        r = g = b = 1.0 - r;
        hsv = false;
*/
        break;

    case Ice:
        hsv = false;
        mapDiscrete(norm, ice, r, g, b);
    }

    if (hsv) {
        return QColor::fromHsvF(h, s, v);
    } else {
        return QColor::fromRgbF(r, g, b);
    }
}

QColor
ColourMapper::getContrastingColour() const
{
    if (m_map >= getColourMapCount()) return Qt::white;
    StandardMap map = (StandardMap)m_map;

    switch (map) {

    case Green:
        return QColor(255, 150, 50);

    case WhiteOnBlack:
        return Qt::red;

    case BlackOnWhite:
        return Qt::darkGreen;

    case Cherry:
        return Qt::green;

    case Wasp:
        return QColor::fromHsv(240, 255, 255);

    case Ice:
        return Qt::red;

    case Sunset:
        return Qt::white;

    case FruitSalad:
        return Qt::white;

    case Banded:
        return Qt::cyan;

    case Highlight:
        return Qt::red;

    case Printer:
        return Qt::red;

    case HighGain:
        return Qt::red;
    }

    return Qt::white;
}

bool
ColourMapper::hasLightBackground() const
{
    if (m_map >= getColourMapCount()) return false;
    StandardMap map = (StandardMap)m_map;

    switch (map) {

    case BlackOnWhite:
    case Printer:
    case HighGain:
        return true;

    case Green:
    case Sunset:
    case WhiteOnBlack:
    case Cherry:
    case Wasp:
    case Ice:
    case FruitSalad:
    case Banded:
    case Highlight:
        
    default:
        return false;
    }
}