qwt_color_map.h

/******************************************************************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2002   Uwe Rathmann
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *
 * Modified by ChenZongYan in 2024 <czy.t@163.com>
 *   Summary of major modifications (see ChangeLog.md for full history):
 *   1. CMake build system & C++11 throughout.
 *   2. Core panner/ zoomer refactored:
 *        - QwtPanner → QwtCachePanner (pixmap-cache version)
 *        - New real-time QwtPlotPanner derived from QwtPicker.
 *   3. Zoomer supports multi-axis.
 *   4. Parasite-plot framework:
 *        - QwtFigure, QwtPlotParasiteLayout, QwtPlotTransparentCanvas,
 *        - QwtPlotScaleEventDispatcher, built-in pan/zoom on axis.
 *   5. New picker: QwtPlotSeriesDataPicker (works with date axis).
 *   6. Raster & color-map extensions:
 *        - QwtGridRasterData (2-D table + interpolation)
 *        - QwtLinearColorMap::stopColors(), stopPos() API rename.
 *   7. Bar-chart: expose pen/brush control.
 *   8. Amalgamated build: single QwtPlot.h / QwtPlot.cpp pair in src-amalgamate.
 *****************************************************************************/
 
#ifndef QWT_COLOR_MAP_H
#define QWT_COLOR_MAP_H
 
#include "qwt_global.h"
#include <qcolor.h>
 
class QwtInterval;
 
#if QT_VERSION < 0x060000
template< typename T >
class QVector;
#endif
 
class QWT_EXPORT QwtColorMap
{
public:
    enum Format
    {
        RGB,
 
        Indexed
    };
 
    explicit QwtColorMap(Format = QwtColorMap::RGB);
    virtual ~QwtColorMap();
 
    void setFormat(Format);
    Format format() const;
 
    virtual QRgb rgb(const QwtInterval& interval, double value) const = 0;
 
    virtual uint colorIndex(int numColors, const QwtInterval& interval, double value) const;
 
    QColor color(const QwtInterval&, double value) const;
    virtual QVector< QRgb > colorTable(int numColors) const;
    virtual QVector< QRgb > colorTable256() const;
 
private:
    Q_DISABLE_COPY(QwtColorMap)
 
    Format m_format;
};
 
class QWT_EXPORT QwtLinearColorMap : public QwtColorMap
{
public:
    enum Mode
    {
        FixedColors,
 
        ScaledColors
    };
 
    explicit QwtLinearColorMap(QwtColorMap::Format = QwtColorMap::RGB);
 
    QwtLinearColorMap(const QColor& from, const QColor& to, QwtColorMap::Format = QwtColorMap::RGB);
 
    virtual ~QwtLinearColorMap();
 
    void setMode(Mode);
    Mode mode() const;
 
    void setColorInterval(const QColor& color1, const QColor& color2);
    void addColorStop(double value, const QColor&);
    QVector< double > stopPos() const;
    QVector< QColor > stopColors() const;
    QColor color1() const;
    QColor color2() const;
 
    virtual QRgb rgb(const QwtInterval&, double value) const override;
 
    virtual uint colorIndex(int numColors, const QwtInterval&, double value) const override;
 
    class ColorStops;
 
private:
    class PrivateData;
    PrivateData* m_data;
};
 
class QWT_EXPORT QwtAlphaColorMap : public QwtColorMap
{
public:
    explicit QwtAlphaColorMap(const QColor& = QColor(Qt::gray));
    virtual ~QwtAlphaColorMap();
 
    void setAlphaInterval(int alpha1, int alpha2);
 
    int alpha1() const;
    int alpha2() const;
 
    void setColor(const QColor&);
    QColor color() const;
 
    virtual QRgb rgb(const QwtInterval&, double value) const override;
 
private:
    class PrivateData;
    PrivateData* m_data;
};
 
class QWT_EXPORT QwtHueColorMap : public QwtColorMap
{
public:
    explicit QwtHueColorMap(QwtColorMap::Format = QwtColorMap::RGB);
    virtual ~QwtHueColorMap();
 
    void setHueInterval(int hue1, int hue2);  // direction ?
    void setSaturation(int saturation);
    void setValue(int value);
    void setAlpha(int alpha);
 
    int hue1() const;
    int hue2() const;
    int saturation() const;
    int value() const;
    int alpha() const;
 
    virtual QRgb rgb(const QwtInterval&, double value) const override;
 
private:
    class PrivateData;
    PrivateData* m_data;
};
 
class QWT_EXPORT QwtSaturationValueColorMap : public QwtColorMap
{
public:
    QwtSaturationValueColorMap();
    virtual ~QwtSaturationValueColorMap();
 
    void setHue(int hue);
    void setSaturationInterval(int sat1, int sat2);
    void setValueInterval(int value1, int value2);
    void setAlpha(int alpha);
 
    int hue() const;
    int saturation1() const;
    int saturation2() const;
    int value1() const;
    int value2() const;
    int alpha() const;
 
    virtual QRgb rgb(const QwtInterval&, double value) const override;
 
private:
    class PrivateData;
    PrivateData* m_data;
};
 
// Map a value into a color.
    inline QColor QwtColorMap::color(const QwtInterval& interval, double value) const
{
    return QColor::fromRgba(rgb(interval, value));
}
 
// Return the intended format of the color map.
    inline QwtColorMap::Format QwtColorMap::format() const
{
    return m_format;
}
 
#endif