2021-07-17c /cad secondary development creation circle (5)

Circle c1 = new Circle();
c1.Center = new Point3d(50, 50, 0);
c1.Radius = 50;

Circle c2 = new Circle(new Point3d(100, 100, 0), new Vector3d(0, 0, 1), 50);

Create a class of circles Circle There are two methods above ：
Through the first Circle Create an object , Then give him the center 、 Radius assignment
Or assign values directly when creating .

Drawing a circle is the same as an arc , Package to AddEnityTool.ca The code is as follows

        /// <summary>
        ///  Draw the circle 
        /// </summary>
        /// <param name="db"> Graphic database </param>
        /// <param name="center"> center of a circle </param>
        /// <param name="radius"> radius </param>
        /// <returns></returns>
        public static ObjectId AddCircleModelSpace(Database db, Point3d center, double radius)
        {
    
            return AddEnityTool.AddEnityToModelSpace(db, new Circle(center, new Vector3d(0, 0, 1), radius));
        }
        /// <summary>
        ///  Draw a circle at two points 
        /// </summary>
        /// <param name="db"> Graphic database </param>
        /// <param name="point1"> The first point </param>
        /// <param name="point2"> Second points </param>
        /// <returns>ObjectId</returns>
        public static ObjectId AddCircleModelSpace(Database db, Point3d point1, Point3d point2) 
        {
    
            // Get the center point 
            Point3d center = BaseTool.GetCenterPointBetweenTwoPoint(point1, point2);
            // Get the radius 
            double radius = BaseTool.GetDistanceBetweenTwoPoint(point1, center);
            return AddEnityTool.AddCircleModelSpace(db, center, radius);
        }
        /// <summary>
        ///  Three point drawing circle 
        /// </summary>
        /// <param name="db"> Graphic database </param>
        /// <param name="point1"> The first point </param>
        /// <param name="point2"> Second points </param>
        /// <param name="point3"> The third point </param>
        /// <returns>ObjectId</returns>
        public static ObjectId AddCircleModelSpace(Database db, Point3d point1, Point3d point2, Point3d point3)
        {
    
            // First judge whether the three points are on the same straight line 
            if (BaseTool.IsOnOneLine(point1, point2, point3))
            {
    
                return ObjectId.Null;
            }
            // Declare the geometry class CircularArc3d object 
            CircularArc3d cArc = new CircularArc3d(point1, point2, point3);
            return AddEnityTool.AddCircleModelSpace(db, cArc.Center, cArc.Radius);
        }
    }
}