/************************** BEGIN ValueConverter.h **************************/
/************************************************************************
 FAUST Architecture File
 Copyright (C) 2003-2017 GRAME, Centre National de Creation Musicale
 ---------------------------------------------------------------------
 This Architecture section 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 3 of
 the License, or (at your option) any later version.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with this program; If not, see <http://www.gnu.org/licenses/>.
 
 EXCEPTION : As a special exception, you may create a larger work
 that contains this FAUST architecture section and distribute
 that work under terms of your choice, so long as this FAUST
 architecture section is not modified.
 ************************************************************************/

#ifndef __ValueConverter__
#define __ValueConverter__

/***************************************************************************************
 ValueConverter.h
 (GRAME, Copyright 2015-2019)
 
 Set of conversion objects used to map user interface values (for example a gui slider
 delivering values between 0 and 1) to faust values (for example a vslider between
 20 and 20000) using a log scale.
 
 -- Utilities
 
 Range(lo,hi) : clip a value x between lo and hi
 Interpolator(lo,hi,v1,v2) : Maps a value x between lo and hi to a value y between v1 and v2
 Interpolator3pt(lo,mi,hi,v1,vm,v2) : Map values between lo mid hi to values between v1 vm v2
 
 -- Value Converters
 
 ValueConverter::ui2faust(x)
 ValueConverter::faust2ui(x)
 
 -- ValueConverters used for sliders depending of the scale
 
 LinearValueConverter(umin, umax, fmin, fmax)
 LinearValueConverter2(lo, mi, hi, v1, vm, v2) using 2 segments
 LogValueConverter(umin, umax, fmin, fmax)
 ExpValueConverter(umin, umax, fmin, fmax)
 
 -- ValueConverters used for accelerometers based on 3 points
 
 AccUpConverter(amin, amid, amax, fmin, fmid, fmax)        -- curve 0
 AccDownConverter(amin, amid, amax, fmin, fmid, fmax)      -- curve 1
 AccUpDownConverter(amin, amid, amax, fmin, fmid, fmax)    -- curve 2
 AccDownUpConverter(amin, amid, amax, fmin, fmid, fmax)    -- curve 3
 
 -- lists of ZoneControl are used to implement accelerometers metadata for each axes
 
 ZoneControl(zone, valueConverter) : a zone with an accelerometer data converter
 
 -- ZoneReader are used to implement screencolor metadata
 
 ZoneReader(zone, valueConverter) : a zone with a data converter

****************************************************************************************/

#include <float.h>
#include <algorithm>    // std::max
#include <cmath>
#include <vector>
#include <assert.h>

//--------------------------------------------------------------------------------------
// Interpolator(lo,hi,v1,v2)
// Maps a value x between lo and hi to a value y between v1 and v2
// y = v1 + (x-lo)/(hi-lo)*(v2-v1)
// y = v1 + (x-lo) * coef           with coef = (v2-v1)/(hi-lo)
// y = v1 + x*coef - lo*coef
// y = v1 - lo*coef + x*coef
// y = offset + x*coef              with offset = v1 - lo*coef
//--------------------------------------------------------------------------------------
class Interpolator
{
    private:

        //--------------------------------------------------------------------------------------
        // Range(lo,hi) clip a value between lo and hi
        //--------------------------------------------------------------------------------------
        struct Range
        {
            double fLo;
            double fHi;

            Range(double x, double y) : fLo(std::min<double>(x,y)), fHi(std::max<double>(x,y)) {}
            double operator()(double x) { return (x<fLo) ? fLo : (x>fHi) ? fHi : x; }
        };


        Range fRange;
        double fCoef;
        double fOffset;

    public:

        Interpolator(double lo, double hi, double v1, double v2) : fRange(lo,hi)
        {
            if (hi != lo) {
                // regular case
                fCoef = (v2-v1)/(hi-lo);
                fOffset = v1 - lo*fCoef;
            } else {
                // degenerate case, avoids division by zero
                fCoef = 0;
                fOffset = (v1+v2)/2;
            }
        }
        double operator()(double v)
        {
            double x = fRange(v);
            return  fOffset + x*fCoef;
        }

        void getLowHigh(double& amin, double& amax)
        {
            amin = fRange.fLo;
            amax = fRange.fHi;
        }
};

//--------------------------------------------------------------------------------------
// Interpolator3pt(lo,mi,hi,v1,vm,v2)
// Map values between lo mid hi to values between v1 vm v2
//--------------------------------------------------------------------------------------
class Interpolator3pt
{

    private:

        Interpolator fSegment1;
        Interpolator fSegment2;
        double fMid;

    public:

        Interpolator3pt(double lo, double mi, double hi, double v1, double vm, double v2) :
            fSegment1(lo, mi, v1, vm),
            fSegment2(mi, hi, vm, v2),
            fMid(mi) {}
        double operator()(double x) { return  (x < fMid) ? fSegment1(x) : fSegment2(x); }

        void getMappingValues(double& amin, double& amid, double& amax)
        {
            fSegment1.getLowHigh(amin, amid);
            fSegment2.getLowHigh(amid, amax);
        }
};

//--------------------------------------------------------------------------------------
// Abstract ValueConverter class. Converts values between UI and Faust representations
//--------------------------------------------------------------------------------------
class ValueConverter // Identity by default
{

    public:

        virtual ~ValueConverter() {}
        virtual double ui2faust(double x) { return x; };
        virtual double faust2ui(double x) { return x; };
};

//--------------------------------------------------------------------------------------
// A converter than can be updated
//--------------------------------------------------------------------------------------

class UpdatableValueConverter : public ValueConverter {
    
    protected:
        
        bool fActive;
        
    public:
        
        UpdatableValueConverter():fActive(true)
        {}
        virtual ~UpdatableValueConverter()
        {}
        
        virtual void setMappingValues(double amin, double amid, double amax, double min, double init, double max) = 0;
        virtual void getMappingValues(double& amin, double& amid, double& amax) = 0;
        
        void setActive(bool on_off) { fActive = on_off; }
        bool getActive() { return fActive; }
    
};

//--------------------------------------------------------------------------------------
// Linear conversion between ui and Faust values
//--------------------------------------------------------------------------------------
class LinearValueConverter : public ValueConverter
{
    
    private:
        
        Interpolator fUI2F;
        Interpolator fF2UI;
        
    public:
        
        LinearValueConverter(double umin, double umax, double fmin, double fmax) :
            fUI2F(umin,umax,fmin,fmax), fF2UI(fmin,fmax,umin,umax)
        {}
        
        LinearValueConverter() : fUI2F(0.,0.,0.,0.), fF2UI(0.,0.,0.,0.)
        {}
        virtual double ui2faust(double x) { return fUI2F(x); }
        virtual double faust2ui(double x) { return fF2UI(x); }
    
};

//--------------------------------------------------------------------------------------
// Two segments linear conversion between ui and Faust values
//--------------------------------------------------------------------------------------
class LinearValueConverter2 : public UpdatableValueConverter
{
    
    private:
    
        Interpolator3pt fUI2F;
        Interpolator3pt fF2UI;
        
    public:
    
        LinearValueConverter2(double amin, double amid, double amax, double min, double init, double max) :
            fUI2F(amin, amid, amax, min, init, max), fF2UI(min, init, max, amin, amid, amax)
        {}
        
        LinearValueConverter2() : fUI2F(0.,0.,0.,0.,0.,0.), fF2UI(0.,0.,0.,0.,0.,0.)
        {}
    
        virtual double ui2faust(double x) { return fUI2F(x); }
        virtual double faust2ui(double x) { return fF2UI(x); }
    
        virtual void setMappingValues(double amin, double amid, double amax, double min, double init, double max)
        {
            fUI2F = Interpolator3pt(amin, amid, amax, min, init, max);
            fF2UI = Interpolator3pt(min, init, max, amin, amid, amax);
        }

        virtual void getMappingValues(double& amin, double& amid, double& amax)
        {
            fUI2F.getMappingValues(amin, amid, amax);
        }
    
};

//--------------------------------------------------------------------------------------
// Logarithmic conversion between ui and Faust values
//--------------------------------------------------------------------------------------
class LogValueConverter : public LinearValueConverter
{

    public:

        LogValueConverter(double umin, double umax, double fmin, double fmax) :
            LinearValueConverter(umin, umax, std::log(std::max<double>(DBL_MIN, fmin)), std::log(std::max<double>(DBL_MIN, fmax)))
        {}

        virtual double ui2faust(double x) { return std::exp(LinearValueConverter::ui2faust(x)); }
        virtual double faust2ui(double x) { return LinearValueConverter::faust2ui(std::log(std::max<double>(x, DBL_MIN))); }

};

//--------------------------------------------------------------------------------------
// Exponential conversion between ui and Faust values
//--------------------------------------------------------------------------------------
class ExpValueConverter : public LinearValueConverter
{

    public:

        ExpValueConverter(double umin, double umax, double fmin, double fmax) :
            LinearValueConverter(umin, umax, std::min<double>(DBL_MAX, std::exp(fmin)), std::min<double>(DBL_MAX, std::exp(fmax)))
        {}

        virtual double ui2faust(double x) { return std::log(LinearValueConverter::ui2faust(x)); }
        virtual double faust2ui(double x) { return LinearValueConverter::faust2ui(std::min<double>(DBL_MAX, std::exp(x))); }

};

//--------------------------------------------------------------------------------------
// Convert accelerometer or gyroscope values to Faust values
// Using an Up curve (curve 0)
//--------------------------------------------------------------------------------------
class AccUpConverter : public UpdatableValueConverter
{

    private:

        Interpolator3pt fA2F;
        Interpolator3pt fF2A;

    public:

        AccUpConverter(double amin, double amid, double amax, double fmin, double fmid, double fmax) :
            fA2F(amin,amid,amax,fmin,fmid,fmax),
            fF2A(fmin,fmid,fmax,amin,amid,amax)
        {}

        virtual double ui2faust(double x) { return fA2F(x); }
        virtual double faust2ui(double x) { return fF2A(x); }

        virtual void setMappingValues(double amin, double amid, double amax, double fmin, double fmid, double fmax)
        {
            //__android_log_print(ANDROID_LOG_ERROR, "Faust", "AccUpConverter update %f %f %f %f %f %f", amin,amid,amax,fmin,fmid,fmax);
            fA2F = Interpolator3pt(amin, amid, amax, fmin, fmid, fmax);
            fF2A = Interpolator3pt(fmin, fmid, fmax, amin, amid, amax);
        }

        virtual void getMappingValues(double& amin, double& amid, double& amax)
        {
            fA2F.getMappingValues(amin, amid, amax);
        }

};

//--------------------------------------------------------------------------------------
// Convert accelerometer or gyroscope values to Faust values
// Using a Down curve (curve 1)
//--------------------------------------------------------------------------------------
class AccDownConverter : public UpdatableValueConverter
{

    private:

        Interpolator3pt	fA2F;
        Interpolator3pt	fF2A;

    public:

        AccDownConverter(double amin, double amid, double amax, double fmin, double fmid, double fmax) :
            fA2F(amin,amid,amax,fmax,fmid,fmin),
            fF2A(fmin,fmid,fmax,amax,amid,amin)
        {}

        virtual double ui2faust(double x) { return fA2F(x); }
        virtual double faust2ui(double x) { return fF2A(x); }

        virtual void setMappingValues(double amin, double amid, double amax, double fmin, double fmid, double fmax)
        {
             //__android_log_print(ANDROID_LOG_ERROR, "Faust", "AccDownConverter update %f %f %f %f %f %f", amin,amid,amax,fmin,fmid,fmax);
            fA2F = Interpolator3pt(amin, amid, amax, fmax, fmid, fmin);
            fF2A = Interpolator3pt(fmin, fmid, fmax, amax, amid, amin);
        }

        virtual void getMappingValues(double& amin, double& amid, double& amax)
        {
            fA2F.getMappingValues(amin, amid, amax);
        }
};

//--------------------------------------------------------------------------------------
// Convert accelerometer or gyroscope values to Faust values
// Using an Up-Down curve (curve 2)
//--------------------------------------------------------------------------------------
class AccUpDownConverter : public UpdatableValueConverter
{

    private:

        Interpolator3pt	fA2F;
        Interpolator fF2A;

    public:

        AccUpDownConverter(double amin, double amid, double amax, double fmin, double fmid, double fmax) :
            fA2F(amin,amid,amax,fmin,fmax,fmin),
            fF2A(fmin,fmax,amin,amax)				// Special, pseudo inverse of a non monotonic function
        {}

        virtual double ui2faust(double x) { return fA2F(x); }
        virtual double faust2ui(double x) { return fF2A(x); }

        virtual void setMappingValues(double amin, double amid, double amax, double fmin, double fmid, double fmax)
        {
            //__android_log_print(ANDROID_LOG_ERROR, "Faust", "AccUpDownConverter update %f %f %f %f %f %f", amin,amid,amax,fmin,fmid,fmax);
            fA2F = Interpolator3pt(amin, amid, amax, fmin, fmax, fmin);
            fF2A = Interpolator(fmin, fmax, amin, amax);
        }

        virtual void getMappingValues(double& amin, double& amid, double& amax)
        {
            fA2F.getMappingValues(amin, amid, amax);
        }
};

//--------------------------------------------------------------------------------------
// Convert accelerometer or gyroscope values to Faust values
// Using a Down-Up curve (curve 3)
//--------------------------------------------------------------------------------------
class AccDownUpConverter : public UpdatableValueConverter
{

    private:

        Interpolator3pt	fA2F;
        Interpolator fF2A;

    public:

        AccDownUpConverter(double amin, double amid, double amax, double fmin, double fmid, double fmax) :
            fA2F(amin,amid,amax,fmax,fmin,fmax),
            fF2A(fmin,fmax,amin,amax)				// Special, pseudo inverse of a non monotonic function
        {}

        virtual double ui2faust(double x) { return fA2F(x); }
        virtual double faust2ui(double x) { return fF2A(x); }

        virtual void setMappingValues(double amin, double amid, double amax, double fmin, double fmid, double fmax)
        {
            //__android_log_print(ANDROID_LOG_ERROR, "Faust", "AccDownUpConverter update %f %f %f %f %f %f", amin,amid,amax,fmin,fmid,fmax);
            fA2F = Interpolator3pt(amin, amid, amax, fmax, fmin, fmax);
            fF2A = Interpolator(fmin, fmax, amin, amax);
        }

        virtual void getMappingValues(double& amin, double& amid, double& amax)
        {
            fA2F.getMappingValues(amin, amid, amax);
        }
};

//--------------------------------------------------------------------------------------
// Base class for ZoneControl
//--------------------------------------------------------------------------------------
class ZoneControl
{

    protected:

        FAUSTFLOAT*	fZone;

    public:

        ZoneControl(FAUSTFLOAT* zone) : fZone(zone) {}
        virtual ~ZoneControl() {}

        virtual void update(double v) const {}

        virtual void setMappingValues(int curve, double amin, double amid, double amax, double min, double init, double max) {}
        virtual void getMappingValues(double& amin, double& amid, double& amax) {}

        FAUSTFLOAT* getZone() { return fZone; }

        virtual void setActive(bool on_off) {}
        virtual bool getActive() { return false; }

        virtual int getCurve() { return -1; }

};

//--------------------------------------------------------------------------------------
//  Useful to implement accelerometers metadata as a list of ZoneControl for each axes
//--------------------------------------------------------------------------------------
class ConverterZoneControl : public ZoneControl
{

    protected:

        ValueConverter* fValueConverter;

    public:

        ConverterZoneControl(FAUSTFLOAT* zone, ValueConverter* converter) : ZoneControl(zone), fValueConverter(converter) {}
        virtual ~ConverterZoneControl() { delete fValueConverter; } // Assuming fValueConverter is not kept elsewhere...

        virtual void update(double v) const { *fZone = fValueConverter->ui2faust(v); }

        ValueConverter* getConverter() { return fValueConverter; }

};

//--------------------------------------------------------------------------------------
// Association of a zone and a four value converter, each one for each possible curve.
// Useful to implement accelerometers metadata as a list of ZoneControl for each axes
//--------------------------------------------------------------------------------------
class CurveZoneControl : public ZoneControl
{

    private:

        std::vector<UpdatableValueConverter*> fValueConverters;
        int fCurve;

    public:

        CurveZoneControl(FAUSTFLOAT* zone, int curve, double amin, double amid, double amax, double min, double init, double max) : ZoneControl(zone), fCurve(0)
        {
            assert(curve >= 0 && curve <= 3);
            fValueConverters.push_back(new AccUpConverter(amin, amid, amax, min, init, max));
            fValueConverters.push_back(new AccDownConverter(amin, amid, amax, min, init, max));
            fValueConverters.push_back(new AccUpDownConverter(amin, amid, amax, min, init, max));
            fValueConverters.push_back(new AccDownUpConverter(amin, amid, amax, min, init, max));
            fCurve = curve;
        }
        virtual ~CurveZoneControl()
        {
            std::vector<UpdatableValueConverter*>::iterator it;
            for (it = fValueConverters.begin(); it != fValueConverters.end(); it++) {
                delete(*it);
            }
        }
        void update(double v) const { if (fValueConverters[fCurve]->getActive()) *fZone = fValueConverters[fCurve]->ui2faust(v); }

        void setMappingValues(int curve, double amin, double amid, double amax, double min, double init, double max)
        {
            fValueConverters[curve]->setMappingValues(amin, amid, amax, min, init, max);
            fCurve = curve;
        }

        void getMappingValues(double& amin, double& amid, double& amax)
        {
            fValueConverters[fCurve]->getMappingValues(amin, amid, amax);
        }

        void setActive(bool on_off)
        {
            std::vector<UpdatableValueConverter*>::iterator it;
            for (it = fValueConverters.begin(); it != fValueConverters.end(); it++) {
                (*it)->setActive(on_off);
            }
        }

        int getCurve() { return fCurve; }
};

class ZoneReader
{

    private:

        FAUSTFLOAT* fZone;
        Interpolator fInterpolator;

    public:

        ZoneReader(FAUSTFLOAT* zone, double lo, double hi) : fZone(zone), fInterpolator(lo, hi, 0, 255) {}

        virtual ~ZoneReader() {}

        int getValue()
        {
            return (fZone != nullptr) ? int(fInterpolator(*fZone)) : 127;
        }

};

#endif
/**************************  END  ValueConverter.h **************************/