Calculate Points and Values (.NET)

By using the methods provided by the Editor object and the Geometry and Runtime namespaces, you can quickly solve a mathematical problem or locate points in your drawing. Some of the available methods are:

• Get the distance between two 2D or 3D points using the GetDistanceTo and DistanceTo methods
• Get the angle from the X-axis using two 2D points using the GetVectorTo method with the Angle property of the returned value
• Convert an angle as a string to a real (double) value with the StringToAngle method
• Convert an angle from a real (double) value to a string with the AngleToString method
• Convert a distance from a string to a real (double) value with the StringToDistance method
• Find the distance between two points entered by the user with the GetDistance method

Note: The AutoCAD .NET API does not contain methods to calculate a point based on a distance and angle (polar point) and for translating coordinates between different coordinate systems. If you need these utilities, you will want to utilize the PolarPoint and TranslateCoordinates methods from the ActiveX Automation library.

Get angle from X-axis

This example calculates a vector between two points and determines the angle from the X-axis.

C# Example

using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.Geometry;
 
[CommandMethod("AngleFromXAxis")]
public static void AngleFromXAxis()
{
  Point2d pt1 = new Point2d(2, 5);
  Point2d pt2 = new Point2d(5, 2);
 
  Application.ShowAlertDialog("Angle from XAxis: " +
                              pt1.GetVectorTo(pt2).Angle.ToString());
}

Calculate Polar Point

This example calculates a point based on a base point, an angle and distance.

C# Example

using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.Geometry;
 
static Point2d PolarPoints(Point2d pPt, double dAng, double dDist)
{
  return new Point2d(pPt.X + dDist * Math.Cos(dAng),
                     pPt.Y + dDist * Math.Sin(dAng));
}
 
static Point3d PolarPoints(Point3d pPt, double dAng, double dDist)
{
  return new Point3d(pPt.X + dDist * Math.Cos(dAng),
                     pPt.Y + dDist * Math.Sin(dAng),
                     pPt.Z);
}
 
[CommandMethod("PolarPoints")]
public static void PolarPoints()
{
  Point2d pt1 = PolarPoints(new Point2d(5, 2), 0.785398, 12);
 
  Application.ShowAlertDialog("\nPolarPoint: " +
                              "\nX = " + pt1.X +
                              "\nY = " + pt1.Y);
 
  Point3d pt2 = PolarPoints(new Point3d(5, 2, 0), 0.785398, 12);
 
  Application.ShowAlertDialog("\nPolarPoint: " +
                              "\nX = " + pt2.X +
                              "\nY = " + pt2.Y +
                              "\nZ = " + pt2.Z);
}

Find the distance between two points with the GetDistance method

This example uses the GetDistance method to obtain two points and displays the calculated distance.

C# Example

using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Runtime;
 
[CommandMethod("GetDistanceBetweenTwoPoints")]
public static void GetDistanceBetweenTwoPoints()
{
  Document acDoc = Application.DocumentManager.MdiActiveDocument;
 
  PromptDoubleResult pDblRes;
  pDblRes = acDoc.Editor.GetDistance("\nPick two points: ");
 
  Application.ShowAlertDialog("\nDistance between points: " +
                              pDblRes.Value.ToString());
}