Visual Studio 2010 Add-in that Adds Diff Tools, Web Project Reporting and Some Subversion Support

// svgPie.cs
// Copyright by Matthias Hertel, http://www.mathertel.de
// This work is licensed under a Creative Commons Attribution 2.0 Germany License.
// See http://creativecommons.org/licenses/by/2.0/de/
// ----- 
// 31.01.2006 created by Matthias Hertel

using System;
using System.Text;

namespace WebReports8 {

  /// <summary>This class renders some svg code that displays a pie graph and can be embedded into html.</summary>
  public abstract class svgPie {

    /// <summary>Return a string containing svg tags that render as a pie chart.</summary>
    /// <param name="data">The data values.</param>
    /// <param name="legend">The labelsof the corresponding data elements.</param>
    /// <returns>Xml text containing svg tags.</returns>
    public static string RenderPie(double[] data, string[] legend) {
      if (data != null) {
        byte r = 0, g=0, b=0xFF;
        byte shiftValue = 0x11;
        string[] colors = new string[data.Length];

        if (data.Length < 9)
          shiftValue = 0x55;
        else if (data.Length < 15)
          shiftValue = 0x33;

        for (int n = 0; n < data.Length; n++) {
          colors[n] = String.Format("#{0:X2}{1:X2}{2:X2}", r, g, b);

          // shift 0x11 value
          if ((r != 0) & (b == 0)) {
            r -= shiftValue;
            g += shiftValue;
          } else if (g != 0) {
            g -= shiftValue;
            b += shiftValue;
          } else {
            b -= shiftValue;
            r += shiftValue;
          } // if

        } // for
        return(RenderPie(data, legend, colors));
      } // if
      return(String.Empty);
    }


    /// <summary>Return a string containing svg tags that render as a pie chart.</summary>
    /// <param name="data">The data values.</param>
    /// <param name="legend">The labelsof the corresponding data elements.</param>
    /// <param name="colors">The colors of the corresponding data elements.</param>
    /// <returns>Xml text containing svg tags.</returns>
    public static string RenderPie(double[] data, string[] legend, string[] colors) {
      StringBuilder sb = new StringBuilder();
      int mx = 200, my = 200;
      int r = 100;
      double sum, curSum;
      int curX, curY;
      int txtX, txtY;
      string txt;

      sb.AppendFormat("<svg:svg width='{0}' height='{1}'>\n", 2*mx, 2*my);

      sum = 0;
      for (int n = 0; n < data.Length; n++)
        sum += data[n];

      // draw the pie
      curSum = 0;
      curX = mx - r;
      curY = my;
      for (int n = 0; n < data.Length; n++) {
        // draw the pie part
        if (data[n] >= sum / 2)
          sb.AppendFormat("<svg:path d='M {0},{1} L {2},{3} A {4} {4} 0 1 1 ",
            mx, my, curX, curY, r );
        else
          sb.AppendFormat("<svg:path d='M {0},{1} L {2},{3} A {4} {4} 0 0 1 ",
            mx, my, curX, curY, r );

        curSum += data[n];
        curX = mx - (int)(r*Math.Cos(2 * curSum * Math.PI / sum));
        curY = my - (int)(r*Math.Sin(2 * curSum * Math.PI / sum));

        sb.AppendFormat("{0},{1} Z' ",curX, curY);

        sb.AppendFormat(" fill='{0}' stroke='black' stroke-width='1' />\n", colors[n]);

        // draw the text

        if ((legend != null) && (legend.Length > n) && (legend[n] != null) && (legend[n].Length > 0)) {
          txt = legend[n];
        } else {
          txt = data[n].ToString();
        } // if

        txtX = mx - (int)(1.3 * r*Math.Cos(2 * (curSum - data[n]/2) * Math.PI / sum));
        txtY = my - (int)(1.3 * r*Math.Sin(2 * (curSum - data[n]/2) * Math.PI / sum));
        sb.AppendFormat("<svg:text x='{0}' y='{1}' text-anchor='middle' style='fill:black'>{2}</svg:text>\n",
          txtX, txtY, txt);
      } // for

      sb.Append("</svg:svg>\n");
      return(sb.ToString());
    }
  }
}