SvgNumber.cs :  » GUI » SharpVectorGraphics » SharpVectors » Dom » Svg » C# / CSharp Open Source

using System;
using System.Diagnostics;
using System.Globalization;
using System.Text.RegularExpressions;

using SharpVectors.Dom.Css;

namespace SharpVectors.Dom.Svg{
  public class SvgNumber : ISvgNumber
  {
    #region Static members
    internal static string numberPattern = @"(?<number>(\+|-)?\d*\.?\d+((e|E)(\+|-)?\d+)?)";
    internal static Regex reNumber = new Regex("^" + numberPattern + "$");

    public static NumberFormatInfo Format
    {
      get
      {
        return CssNumber.Format;
      }
    }

    private static Regex reUnit = new Regex("[a-z]+$");
    public static string ScientificToDec(string sc)
    {
      if(sc.IndexOfAny(new char[]{'e','E'})>-1)
      {
        sc = sc.Trim();
        // remove the unit
        Match match = reUnit.Match(sc);
        return SvgNumber.ParseToFloat(sc.Substring(0, sc.Length - match.Length)).ToString(Format) + match.Value;
      }
      else
      {
        return sc;
      }
    }

    public static float ParseToFloat(string str)
    {
      float val;
      int index = str.IndexOfAny(new Char[]{'E','e'});
      if(index>-1)
      {
        float number = SvgNumber.ParseToFloat(str.Substring(0, index));
        float power = SvgNumber.ParseToFloat(str.Substring(index+1));

        val = (float) Math.Pow(10, power) * number;
      }
      else
      {
        try
        {
          val = Single.Parse(str, SvgNumber.Format);
        }
        catch(Exception e)
        {
          throw new DomException(DomExceptionType.SyntaxErr, "Input string was not in a correct format: " + str, e);
        }
      }
      return val;
    }
    

    public static float CalcAngleDiff(float a1, float a2)
    {
      while(a1 < 0) a1 += 360;
      a1 %= 360;

      while(a2 < 0) a2 += 360;
      a2 %= 360;

      float diff = (a1-a2);

      while(diff<0) diff += 360;
      diff %= 360;
            
      return diff;
    }
    public static float CalcAngleBisection(float a1, float a2)
    {
      float diff = CalcAngleDiff(a1, a2);
      float bisect = a1 - diff/2F;

      while(bisect<0) bisect += 360;

      bisect %= 360;
      return bisect;
    }
    #endregion

    #region Constructors
    public SvgNumber(float val)
    {
      _value = val;
    }

    public SvgNumber(string str)
    {
      _value = SvgNumber.ParseToFloat(str);
    }

    #endregion

    #region Implementation of ISvgNumber
    private float _value;
    public float Value
    {
      get
      {
        return _value;
      }
      set
      {
        this._value = value;
      }
    }

    #endregion

  }
}