#pragma once
 
#ifndef T_COLOR_FUNCTIONS_INCLUDED
#define T_COLOR_FUNCTIONS_INCLUDED
 
#include "tpixel.h"
 
#undef DVAPI
#undef DVVAR
#ifdef TCOLOR_EXPORTS
#define DVAPI DV_EXPORT_API
#define DVVAR DV_EXPORT_VAR
#else
#define DVAPI DV_IMPORT_API
#define DVVAR DV_IMPORT_VAR
#endif
 
//-----------------------------------------------------------------------------
 
class DVAPI TColorFunction {
public:
  virtual TPixel32 operator()(
      const TPixel32 &color) const = 0;  // {return color;};
 
  struct Parameters {  // outX = tcrop(inX * m_mX + m_cX, 0, 1); 0<=inX<=1
    double m_mR, m_mG, m_mB, m_mM;
    double m_cR, m_cG, m_cB, m_cM;
    Parameters()
        : m_mR(1)
        , m_mG(1)
        , m_mB(1)
        , m_mM(1)
        , m_cR(0)
        , m_cG(0)
        , m_cB(0)
        , m_cM(0) {}
  };
 
  virtual TColorFunction *clone() const = 0;
  virtual bool getParameters(
      Parameters &p) const = 0;  //{ p = Parameters(); return true; }
 
  virtual ~TColorFunction() {}
};
 
//-----------------------------------------------------------------------------
 
class DVAPI TGenericColorFunction final : public TColorFunction {
  double m_m[4], m_c[4];
 
public:
  TGenericColorFunction(const double m[4], const double c[4]);
 
  TColorFunction *clone() const override {
    return new TGenericColorFunction(m_m, m_c);
  }
 
  TPixel32 operator()(const TPixel32 &color) const override;
  bool getParameters(Parameters &p) const override;
};
 
//-----------------------------------------------------------------------------
 
class DVAPI TColorFader final : public TColorFunction {
  TPixel32 m_color;
  double m_fade;
 
public:
  TColorFader() : m_color(), m_fade(0.5) {}
  TColorFader(const TPixel32 &color, double fade)
      : m_color(color), m_fade(fade) {}
 
  TColorFunction *clone() const override {
    return new TColorFader(m_color, m_fade);
  }
 
  TPixel32 operator()(const TPixel32 &color) const override;
  bool getParameters(Parameters &p) const override;
};
 
//-----------------------------------------------------------------------------
 
class DVAPI TOnionFader final : public TColorFunction {
  TPixel32 m_color;
  double m_fade;
 
public:
  TOnionFader() : m_color(), m_fade(0.5) {}
  TOnionFader(const TPixel32 &color, double fade)
      : m_color(color), m_fade(fade) {}
 
  TColorFunction *clone() const override {
    return new TOnionFader(m_color, m_fade);
  }
 
  TPixel32 operator()(const TPixel32 &color) const override;
  bool getParameters(Parameters &p) const override;
};
 
class DVAPI TTranspFader final : public TColorFunction {
  double m_transp;
 
public:
  TTranspFader() : m_transp(0.5) {}
  TTranspFader(double transp) : m_transp(transp) {}
 
  TColorFunction *clone() const override { return new TTranspFader(m_transp); }
 
  TPixel32 operator()(const TPixel32 &color) const override;
  bool getParameters(Parameters &p) const override;
};
 
#endif