Beispiel #1
0
        /********************************************************
         * To check whether 2 lines segments have an intersection
         *********************************************************/
        public bool IntersectedWith(CLineSegment line)
        {
            double x1 = this.m_startPoint.X;
            double y1 = this.m_startPoint.Y;
            double x2 = this.m_endPoint.X;
            double y2 = this.m_endPoint.Y;
            double x3 = line.m_startPoint.X;
            double y3 = line.m_startPoint.Y;
            double x4 = line.m_endPoint.X;
            double y4 = line.m_endPoint.Y;

            double de = (y4 - y3) * (x2 - x1) - (x4 - x3) * (y2 - y1);

            //if de<>0 then //lines are not parallel
            if (Math.Abs(de - 0) < ConstantValue.SmallValue)         //not parallel
            {
                double ua = ((x4 - x3) * (y1 - y3) - (y4 - y3) * (x1 - x3)) / de;
                double ub = ((x2 - x1) * (y1 - y3) - (y2 - y1) * (x1 - x3)) / de;

                if ((ub > 0) && (ub < 1))
                {
                    return(true);
                }
                else
                {
                    return(false);
                }
            }
            else                //lines are parallel
            {
                return(false);
            }
        }
Beispiel #2
0
        /***To check whether the point is in a line segment***/
        public bool InLine(CLineSegment lineSegment)
        {
            bool bInline = false;

            double Ax, Ay, Bx, By, Cx, Cy;

            Bx = lineSegment.EndPoint.X;
            By = lineSegment.EndPoint.Y;
            Ax = lineSegment.StartPoint.X;
            Ay = lineSegment.StartPoint.Y;
            Cx = this.m_dCoordinate_X;
            Cy = this.m_dCoordinate_Y;

            double L = lineSegment.GetLineSegmentLength();
            double s = Math.Abs(((Ay - Cy) * (Bx - Ax) - (Ax - Cx) * (By - Ay)) / (L * L));

            if (Math.Abs(s - 0) < ConstantValue.SmallValue)
            {
                if ((SamePoints(this, lineSegment.StartPoint)) ||
                    (SamePoints(this, lineSegment.EndPoint)))
                {
                    bInline = true;
                }
                else if ((Cx < lineSegment.GetXmax()) &&
                         (Cx > lineSegment.GetXmin()) &&
                         (Cy < lineSegment.GetYmax()) &&
                         (Cy > lineSegment.GetYmin()))
                {
                    bInline = true;
                }
            }
            return(bInline);
        }
Beispiel #3
0
        /***Check whether this line is in a longer line***/
        public bool InLine(CLineSegment longerLineSegment)
        {
            bool bInLine = false;

            if ((m_startPoint.InLine(longerLineSegment)) &&
                (m_endPoint.InLine(longerLineSegment)))
            {
                bInLine = true;
            }
            return(bInLine);
        }
Beispiel #4
0
        /************************************************
         * Offset the line segment to generate a new line segment
         * If the offset direction is along the x-axis or y-axis,
         * Parameter is true, other wise it is false
         * ***********************************************/
        public CLineSegment OffsetLine(double distance, bool rightOrDown)
        {
            //offset a line with a given distance, generate a new line
            //rightOrDown=true means offset to x incress direction,
            // if the line is horizontal, offset to y incress direction

            CLineSegment line;
            CPoint2D     newStartPoint = new CPoint2D();
            CPoint2D     newEndPoint   = new CPoint2D();

            double alphaInRad = this.GetLineAngle();            // 0-PI

            if (rightOrDown)
            {
                if (this.HorizontalLine())                 //offset to y+ direction
                {
                    newStartPoint.X = this.m_startPoint.X;
                    newStartPoint.Y = this.m_startPoint.Y + distance;

                    newEndPoint.X = this.m_endPoint.X;
                    newEndPoint.Y = this.m_endPoint.Y + distance;
                    line          = new CLineSegment(newStartPoint, newEndPoint);
                }
                else                 //offset to x+ direction
                {
                    if (Math.Sin(alphaInRad) > 0)
                    {
                        newStartPoint.X = m_startPoint.X + Math.Abs(distance * Math.Sin(alphaInRad));
                        newStartPoint.Y = m_startPoint.Y - Math.Abs(distance * Math.Cos(alphaInRad));

                        newEndPoint.X = m_endPoint.X + Math.Abs(distance * Math.Sin(alphaInRad));
                        newEndPoint.Y = m_endPoint.Y - Math.Abs(distance * Math.Cos(alphaInRad));

                        line = new CLineSegment(
                            newStartPoint, newEndPoint);
                    }
                    else                     //sin(FalphaInRad)<0
                    {
                        newStartPoint.X = m_startPoint.X + Math.Abs(distance * Math.Sin(alphaInRad));
                        newStartPoint.Y = m_startPoint.Y + Math.Abs(distance * Math.Cos(alphaInRad));
                        newEndPoint.X   = m_endPoint.X + Math.Abs(distance * Math.Sin(alphaInRad));
                        newEndPoint.Y   = m_endPoint.Y + Math.Abs(distance * Math.Cos(alphaInRad));

                        line = new CLineSegment(
                            newStartPoint, newEndPoint);
                    }
                }
            }                              //{rightOrDown}
            else                           //leftOrUp
            {
                if (this.HorizontalLine()) //offset to y directin
                {
                    newStartPoint.X = m_startPoint.X;
                    newStartPoint.Y = m_startPoint.Y - distance;

                    newEndPoint.X = m_endPoint.X;
                    newEndPoint.Y = m_endPoint.Y - distance;
                    line          = new CLineSegment(
                        newStartPoint, newEndPoint);
                }
                else                 //offset to x directin
                {
                    if (Math.Sin(alphaInRad) >= 0)
                    {
                        newStartPoint.X = m_startPoint.X - Math.Abs(distance * Math.Sin(alphaInRad));
                        newStartPoint.Y = m_startPoint.Y + Math.Abs(distance * Math.Cos(alphaInRad));
                        newEndPoint.X   = m_endPoint.X - Math.Abs(distance * Math.Sin(alphaInRad));
                        newEndPoint.Y   = m_endPoint.Y + Math.Abs(distance * Math.Cos(alphaInRad));

                        line = new CLineSegment(
                            newStartPoint, newEndPoint);
                    }
                    else                     //sin(FalphaInRad)<0
                    {
                        newStartPoint.X = m_startPoint.X - Math.Abs(distance * Math.Sin(alphaInRad));
                        newStartPoint.Y = m_startPoint.Y - Math.Abs(distance * Math.Cos(alphaInRad));
                        newEndPoint.X   = m_endPoint.X - Math.Abs(distance * Math.Sin(alphaInRad));
                        newEndPoint.Y   = m_endPoint.Y - Math.Abs(distance * Math.Cos(alphaInRad));

                        line = new CLineSegment(
                            newStartPoint, newEndPoint);
                    }
                }
            }
            return(line);
        }