# DesignerGeometryHelper.cs source code in C# .NET

## Source code for the .NET framework in C#

```                        Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / NetFx40 / Tools / System.Activities.Core.Presentation / System / Activities / Core / Presentation / DesignerGeometryHelper.cs / 1305376 / DesignerGeometryHelper.cs

//------------------------------------------------------------
//-----------------------------------------------------------

namespace System.Activities.Core.Presentation
{
using System.Windows;
using System.Windows.Media;
using System.Windows.Shapes;
internal static class DesignerGeometryHelper
{
const double EPS = 1e-6;

public static double DistanceBetweenPoints(Point point1, Point point2)
{
double d = Math.Sqrt(Math.Pow(point2.X - point1.X, 2) + Math.Pow(point2.Y - point1.Y, 2));
return d;
}

//Distance from point to nearest linesegment on a connector.
//Assuming lines are horizontal or vertical.
//Note that this might not always be the perpendicular distance from point to a line
public static double DistanceFromPointToConnector(Point point, Connector connector)
{
double minDist = Double.PositiveInfinity;
double dist = 0;
for (int i = 0; i < connector.Points.Count - 1; i++)
{
Point p1 = connector.Points[i];
Point p2 = connector.Points[i + 1];
//This condition checks if a perpendicular from the point to the linesegment can be drawn.
if (p1.X == p2.X && point.Y >= Math.Min(p1.Y, p2.Y) && point.Y <= Math.Max(p1.Y, p2.Y))
{
dist = Math.Abs(p1.X - point.X);
}
else if(p1.Y == p2.Y && point.X >= Math.Min(p1.X, p2.X) && point.X <= Math.Max(p1.X, p2.X))
{
dist = Math.Abs(p1.Y - point.Y);
}
else
{
dist = Math.Min(DistanceBetweenPoints(point, p1), DistanceBetweenPoints(point, p2));
}
minDist = (dist < minDist) ? dist : minDist;
}
return minDist;
}

//Distance perpendicular from point to line segment
//Returns the length of the perpendicular from point to the line containing the linesegment.
public static double DistanceFromPointToLineSegment(Point point, Point[] line)
{
int area = (int)Math.Abs((((point.Y - line[0].Y) * (line[1].X - line[0].X)) - ((point.X - line[0].X) * (line[1].Y - line[0].Y))));
return Math.Sqrt(Math.Pow(area, 2) / (Math.Pow((line[1].X - line[0].X), 2) + Math.Pow((line[1].Y - line[0].Y), 2)));
}

//This function calculates the total length of line segments by adding individual lengths
public static double DistanceOfLineSegments(Point[] segments)
{
double distance = 0;
for (int i = 1; i < segments.Length; i++)
{
distance += DistanceBetweenPoints(segments[i - 1], segments[i]);
}
return distance;
}

//Midpoint of line mid = X1 + X2 / 2, Y1 + Y2 /2
public static Point MidPointOfLineSegment(Point point1, Point point2)
{
return new Point(Math.Round((point1.X + point2.X) / 2), Math.Round((point1.Y + point2.Y) / 2));
}

public static double SlopeOfLineSegment(Point start, Point end)
{
//If line is vertical then the slope is infinite
if (start.X == end.X)
{
return double.MaxValue;
}

//If the line is horizontal then slope is 0
if (start.Y == end.Y)
{
return 0;
}

return ((end.Y - start.Y) / (end.X - start.X));
}

//This function returns the length of the longest segment in a PointsCollection.
//The segments are assumed to be HORIZONTAL or VERTICAL.
//the out parameter returns the start point of the longest segment.
//Use equal to avoid the precision problem for double.
//We always choose the first segment among the segements with max length.
public static double LongestSegmentLength(PointCollection points, out int longestSegmentIndex)
{
double maxLength = 0;
longestSegmentIndex = -1;
for (int i = 0; i < points.Count - 1; i++)
{
double length = Math.Abs((points[i].X == points[i + 1].X) ? points[i].Y - points[i + 1].Y : points[i].X - points[i + 1].X);
if (!Equal(length, maxLength) && length > maxLength)
{
maxLength = length;
longestSegmentIndex = i;
}
}

return maxLength;
}

static bool Equal(double num1, double num2)
{
return Math.Abs(num1 - num2) < EPS;
}
}

}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

SyntaxHighlighter.all()

```