Chris@1068: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@1068: 
Chris@1068: /*
Chris@1068:     Sonic Visualiser
Chris@1068:     An audio file viewer and annotation editor.
Chris@1068:     Centre for Digital Music, Queen Mary, University of London.
Chris@1068:     This file copyright 2006-2016 Chris Cannam and QMUL.
Chris@1068:     
Chris@1068:     This program is free software; you can redistribute it and/or
Chris@1068:     modify it under the terms of the GNU General Public License as
Chris@1068:     published by the Free Software Foundation; either version 2 of the
Chris@1068:     License, or (at your option) any later version.  See the file
Chris@1068:     COPYING included with this distribution for more information.
Chris@1068: */
Chris@1068: 
Chris@1068: #ifndef COLOUR_SCALE_H
Chris@1068: #define COLOUR_SCALE_H
Chris@1068: 
Chris@1068: #include "ColourMapper.h"
Chris@1068: 
Chris@1105: enum class ColourScaleType {
Chris@1105:     Linear,
Chris@1105:     Meter,
Chris@1105:     Log,
Chris@1105:     Phase,
Chris@1105:     PlusMinusOne,
Chris@1105:     Absolute
Chris@1105: };
Chris@1105: 
Chris@1068: /**
Chris@1068:  * Map values within a range onto a set of colours, with a given
Chris@1068:  * distribution (linear, log etc) and optional colourmap rotation.
Chris@1068:  */
Chris@1068: class ColourScale
Chris@1068: {
Chris@1068: public:
Chris@1070:     struct Parameters {
Chris@1266:         Parameters() : colourMap(0), scaleType(ColourScaleType::Linear),
Chris@1266:                        minValue(0.0), maxValue(1.0),
Chris@1266:                        threshold(0.0), gain(1.0), multiple(1.0) { }
Chris@1070: 
Chris@1266:         /** A colour map index as used by ColourMapper */
Chris@1266:         int colourMap;
Chris@1266:         
Chris@1266:         /** Distribution for the scale */
Chris@1266:         ColourScaleType scaleType;
Chris@1266:         
Chris@1266:         /** Minimum value in source range */
Chris@1266:         double minValue;
Chris@1266:         
Chris@1266:         /** Maximum value in source range. Must be > minValue */
Chris@1266:         double maxValue;
Chris@1070: 
Chris@1266:         /** Threshold below which every value is mapped to background
Chris@1266:             pixel 0 */
Chris@1266:         double threshold;
Chris@1070: 
Chris@1266:         /** Gain to apply before thresholding, mapping, and clamping */
Chris@1266:         double gain;
Chris@1137: 
Chris@1137:         /** Multiple to apply after thresholding and mapping. In most
Chris@1137:          *  cases the gain parameter is the one you want instead of
Chris@1137:          *  this, but this can be used for example with Log scale to
Chris@1137:          *  produce the log of some power of the original value,
Chris@1137:          *  e.g. multiple = 2 gives log(x^2). */
Chris@1137:         double multiple;
Chris@1070:     };
Chris@1070:     
Chris@1068:     /**
Chris@1070:      * Create a ColourScale with the given parameters.
Chris@1068:      *
Chris@1068:      * Note that some parameters may be ignored for some scale
Chris@1068:      * distribution settings. For example, min and max are ignored for
Chris@1068:      * PlusMinusOneScale and PhaseColourScale and threshold and gain
Chris@1068:      * are ignored for PhaseColourScale.
Chris@1068:      */
Chris@1070:     ColourScale(Parameters parameters);
Chris@1071:     ~ColourScale();
Chris@1068: 
Chris@1071:     ColourScale(const ColourScale &) = default;
Chris@1071:     ColourScale &operator=(const ColourScale &) = default;
Chris@1079: 
Chris@1079:     /**
Chris@1079:      * Return the general type of scale this is.
Chris@1079:      */
Chris@1105:     ColourScaleType getScale() const;
Chris@1071:     
Chris@1068:     /**
Chris@1068:      * Return a pixel number (in the range 0-255 inclusive)
Chris@1068:      * corresponding to the given value.  The pixel 0 is used only for
Chris@1068:      * values below the threshold supplied in the constructor. All
Chris@1068:      * other values are mapped onto the range 1-255.
Chris@1068:      */
Chris@1079:     int getPixel(double value) const;
Chris@1068: 
Chris@1068:     /**
Chris@1068:      * Return the colour for the given pixel number (which must be in
Chris@1068:      * the range 0-255). The pixel 0 is always the background
Chris@1068:      * colour. Other pixels are mapped taking into account the given
Chris@1068:      * colourmap rotation (which is also a value in the range 0-255).
Chris@1068:      */
Chris@1079:     QColor getColourForPixel(int pixel, int rotation) const;
Chris@1068:     
Chris@1068:     /**
Chris@1068:      * Return the colour corresponding to the given value. This is
Chris@1068:      * equivalent to getColourForPixel(getPixel(value), rotation).
Chris@1068:      */
Chris@1079:     QColor getColour(double value, int rotation) const {
Chris@1266:         return getColourForPixel(getPixel(value), rotation);
Chris@1068:     }
Chris@1068: 
Chris@1068: private:
Chris@1070:     Parameters m_params;
Chris@1068:     ColourMapper m_mapper;
Chris@1068:     double m_mappedMin;
Chris@1068:     double m_mappedMax;
Chris@1068:     static int m_maxPixel;
Chris@1068: };
Chris@1068: 
Chris@1068: #endif