comparison layer/ColourScale.h @ 1148:c0d841cb8ab9 tony-2.0-integration

Merge latest SV 3.0 branch code

+/* -*- 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 COLOUR_SCALE_H
+#define COLOUR_SCALE_H
+
+#include "ColourMapper.h"
+
+enum class ColourScaleType {
+    Linear,
+    Meter,
+    Log,
+    Phase,
+    PlusMinusOne,
+    Absolute
+};
+
+/**
+ * Map values within a range onto a set of colours, with a given
+ * distribution (linear, log etc) and optional colourmap rotation.
+ */
+class ColourScale
+{
+public:
+    struct Parameters {
+	Parameters() : colourMap(0), scaleType(ColourScaleType::Linear),
+		       minValue(0.0), maxValue(1.0),
+		       threshold(0.0), gain(1.0), multiple(1.0) { }
+
+	/** A colour map index as used by ColourMapper */
+	int colourMap;
+	
+	/** Distribution for the scale */
+	ColourScaleType scaleType;
+	
+	/** Minimum value in source range */
+	double minValue;
+	
+	/** Maximum value in source range. Must be > minValue */
+	double maxValue;
+
+	/** Threshold below which every value is mapped to background
+	    pixel 0 */
+	double threshold;
+
+	/** Gain to apply before thresholding, mapping, and clamping */
+	double gain;
+
+        /** Multiple to apply after thresholding and mapping. In most
+         *  cases the gain parameter is the one you want instead of
+         *  this, but this can be used for example with Log scale to
+         *  produce the log of some power of the original value,
+         *  e.g. multiple = 2 gives log(x^2). */
+        double multiple;
+    };
+    
+    /**
+     * Create a ColourScale with the given parameters.
+     *
+     * Note that some parameters may be ignored for some scale
+     * distribution settings. For example, min and max are ignored for
+     * PlusMinusOneScale and PhaseColourScale and threshold and gain
+     * are ignored for PhaseColourScale.
+     */
+    ColourScale(Parameters parameters);
+    ~ColourScale();
+
+    ColourScale(const ColourScale &) = default;
+    ColourScale &operator=(const ColourScale &) = default;
+
+    /**
+     * Return the general type of scale this is.
+     */
+    ColourScaleType getScale() const;
+    
+    /**
+     * Return a pixel number (in the range 0-255 inclusive)
+     * corresponding to the given value.  The pixel 0 is used only for
+     * values below the threshold supplied in the constructor. All
+     * other values are mapped onto the range 1-255.
+     */
+    int getPixel(double value) const;
+
+    /**
+     * Return the colour for the given pixel number (which must be in
+     * the range 0-255). The pixel 0 is always the background
+     * colour. Other pixels are mapped taking into account the given
+     * colourmap rotation (which is also a value in the range 0-255).
+     */
+    QColor getColourForPixel(int pixel, int rotation) const;
+    
+    /**
+     * Return the colour corresponding to the given value. This is
+     * equivalent to getColourForPixel(getPixel(value), rotation).
+     */
+    QColor getColour(double value, int rotation) const {
+	return getColourForPixel(getPixel(value), rotation);
+    }
+
+private:
+    Parameters m_params;
+    ColourMapper m_mapper;
+    double m_mappedMin;
+    double m_mappedMax;
+    static int m_maxPixel;
+};
+
+#endif