comparison layer/ColourMapper.cpp @ 196:22c99c8aa1e0

* Add separate colour mapping unit; use it in spectrogram (colour 3d plot to follow)
* Add another colour scheme resembling that of a noted commercial application

+/* -*- 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"
+
+ColourMapper::ColourMapper(int map, float min, float max) :
+    QObject(),
+    m_map(map),
+    m_min(min),
+    m_max(max)
+{
+}
+
+ColourMapper::~ColourMapper()
+{
+}
+
+int
+ColourMapper::getColourMapCount()
+{
+    return 8;
+}
+
+QString
+ColourMapper::getColourMapName(int n)
+{
+    if (n >= 8) return tr("<unknown>");
+    StandardMap map = (StandardMap)n;
+
+    switch (map) {
+    case DefaultColours:   return tr("Default");
+    case WhiteOnBlack:     return tr("White on Black");
+    case BlackOnWhite:     return tr("Black on White");
+    case RedOnBlue:        return tr("Red on Blue");
+    case YellowOnBlack:    return tr("Yellow on Black");
+    case BlueOnBlack:      return tr("Blue on Black");
+    case Sunset:           return tr("Sunset");
+    case FruitSalad:       return tr("Fruit Salad");
+    }
+
+    return tr("<unknown>");
+}
+
+QColor
+ColourMapper::map(float value) const
+{
+    float norm = (value - m_min) / (m_max - m_min);
+    if (norm < 0.f) norm = 0.f;
+    if (norm > 1.f) norm = 1.f;
+    
+    float h = 0.f, s = 0.f, v = 0.f, r = 0.f, g = 0.f, b = 0.f;
+    bool hsv = true;
+
+    float red = 0.f, green = 0.3333f, blue = 0.6666f, pieslice = 0.3333f;
+
+    if (m_map >= 8) return Qt::black;
+    StandardMap map = (StandardMap)m_map;
+
+    switch (map) {
+
+    case DefaultColours:
+        h = blue - norm * 2.f * pieslice;
+        s = 0.5f + norm/2.f;
+        v = norm;
+        break;
+
+    case WhiteOnBlack:
+        r = g = b = norm;
+        hsv = false;
+        break;
+
+    case BlackOnWhite:
+        r = g = b = 1.f - norm;
+        hsv = false;
+        break;
+
+    case RedOnBlue:
+        h = blue - pieslice/4.f + norm * (pieslice + pieslice/4.f);
+        s = 1.f;
+        v = norm;
+        break;
+
+    case YellowOnBlack:
+        h = 0.15f;
+        s = 1.f;
+        v = norm;
+        break;
+
+    case BlueOnBlack:
+        h = blue / 1.f;
+        s = 1.f;
+        v = norm * 2.f;
+        if (v > 1) {
+            v = 1.f;
+            s = 1.f - (sqrtf(norm) - 0.707f) * 3.414f;
+        }
+        break;
+
+    case Sunset:
+        r = (norm - 0.24f) * 2.38f;
+        if (r > 1.f) r = 1.f;
+        if (r < 0.f) r = 0.f;
+        g = (norm - 0.64f) * 2.777f;
+        if (g > 1.f) g = 1.f;
+        if (g < 0.f) g = 0.f;
+        b = (3.6f * norm);
+        if (norm > 0.277f) b = 2.f - b;
+        if (b > 1.f) b = 1.f;
+        if (b < 0.f) b = 0.f;
+        hsv = false;
+        break;
+
+    case FruitSalad:
+        h = blue + (pieslice/2.f) - norm;
+        if (h < 0.f) h += 1.f;
+        s = 1.f;
+        v = 1.f;
+        break;
+    }
+
+    if (hsv) {
+        return QColor::fromHsvF(h, s, v);
+    } else {
+        return QColor::fromRgbF(r, g, b);
+    }
+}
+
+QColor
+ColourMapper::getContrastingColour() const
+{
+    if (m_map >= 8) return Qt::white;
+    StandardMap map = (StandardMap)m_map;
+
+    switch (map) {
+
+    case DefaultColours:
+        return QColor(255, 150, 50);
+
+    case WhiteOnBlack:
+        return Qt::red;
+
+    case BlackOnWhite:
+        return Qt::darkGreen;
+
+    case RedOnBlue:
+        return Qt::green;
+
+    case YellowOnBlack:
+        return QColor::fromHsv(240, 255, 255);
+
+    case BlueOnBlack:
+        return Qt::red;
+
+    case Sunset:
+        return Qt::white;
+
+    case FruitSalad:
+        return Qt::white;
+    }
+
+    return Qt::white;
+}
+
+