GaugeRadialPointer.h

#pragma once 
/*
  AWind.h - Arduino window library support for Color TFT LCD Boards
  Copyright (C)2015 Andrei Degtiarev. All right reserved
  

  You can always find the latest version of the library at 
  https://github.com/AndreiDegtiarev/AWind


  This library is free software; you can redistribute it and/or
  modify it under the terms of the CC BY-NC-SA 3.0 license.
  Please see the included documents for further information.

  Commercial use of this library requires you to buy a license that
  will allow commercial use. This includes using the library,
  modified or not, as a tool to sell products.

  The license applies to all part of the library including the 
  examples and tools supplied with the library.
*/
#include "Gauge.h"
class GaugeRadialPointer : public Gauge
{
    int _numTicks; 

public:

    static const float _sector_angle_rad;


    GaugeRadialPointer(int left,int top,int width,int height)
        :Gauge(left,top,width,height),_numTicks(5)

    {
    }

    void SetNumberOfTicks(int numTicks)
    {
        _numTicks=numTicks;
    }

    void OnDraw(DC *dc)
    {
        dc->SetFont(SmallFont);
        float range=_maxValue-_minValue;
        float step_val=(range)/(_numTicks-1);
        float factor=1000/range;
        int radius=Height()*1;
        int x0=Width()/2;
        int y0=Height()*1.4;
        if(!_drawOnlyPointer)
        {
            dc->DrawRoundRect(2,2,Width()-2,Height()-2);
            dc->Sector(x0,y0,radius,_sector_angle_rad);
            float angle_step=_sector_angle_rad/(_numTicks-1.0);
            float angle;
            float sin_val;
            float cos_val;
            float value;
            int x_offset;
            for(int i=0;i<_numTicks;i++)
            {
                angle=-_sector_angle_rad/2.0+angle_step*i;
                sin_val=sin(angle);
                cos_val=cos(angle);
                dc->MoveTo(x0+radius*sin_val,y0-radius*cos_val);
                dc->LineTo(x0+radius*1.1*sin_val,y0-radius*1.1*cos_val);
                value=_minValue+step_val*i;
                x_offset=AHelper::GetNumberLength(value,1);
                if(value<0)
                    x_offset++;
                if(i==0)
                    x_offset=0;
                else if(i == _numTicks-1)
                    x_offset=-(x_offset-0.5)*dc->FontWidth();
                else
                    x_offset=-x_offset/2*dc->FontWidth();
                dc->DrawNumber(value,1,x0+radius*1.1*sin_val+x_offset,y0-radius*1.1*cos_val-(dc->FontHeight()*(i==0||i==_numTicks-1?1.5:1)));
            }
        }
        dc->SetColor(_fillColor);
        DrawPointer(_oldValue,x0,y0,radius,dc);
        dc->SetColor(Color::Red);
        DrawPointer(_value,x0,y0,radius,dc);
    }
private:
    void DrawPointer(float value,int x0,int y0,int radius,DC *dc)
    {
        //dc->SetColor(color);
        float dc_val=1000/(_maxValue-_minValue)*(value-_minValue);
        float angle=-_sector_angle_rad/2.0+_sector_angle_rad/1000.0*dc_val;
        float sin_val=sin(angle);
        float cos_val=cos(angle);
        for(int i=-3;i<4;i++)
        {
            dc->MoveTo(x0+radius*0.95*sin_val,y0-radius*0.95*cos_val);
            dc->LineTo(x0+i+radius*0.5*sin_val,y0-radius*0.5*cos_val);
        }

    }
};
const float GaugeRadialPointer::_sector_angle_rad = 3.14 / 2 * 0.8;