Ejemplo n.º 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) < CPolygon.thresh)             //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);
            }
        }
Ejemplo n.º 2
0
        /***Check whether this line is in a longer line***/
        public bool InLine(CLineSegment longerLineSegment)
        {
            bool bInLine = false;

            if (longerLineSegment.PointInLine(m_startPoint) &&
                longerLineSegment.PointInLine(m_endPoint))
            {
                bInLine = true;
            }
            return(bInLine);
        }
Ejemplo n.º 3
0
        /**********************************************************
         * To check the Pt is in the Triangle or not.
         * If the Pt is in the line or is a vertex, then return true.
         * If the Pt is out of the Triangle, then return false.
         *
         * This method is used for triangle only.
         ***********************************************************/
        private bool TriangleContainsPoint(Vector2d[] trianglePts, Vector2d pt)
        {
            if (trianglePts.Length != 3)
            {
                return(false);
            }

            for (int i = trianglePts.GetLowerBound(0);
                 i < trianglePts.GetUpperBound(0); i++)
            {
                if (pt.EqualsPoint(trianglePts[i]))
                {
                    return(true);
                }
            }

            bool bIn = false;

            CLineSegment line0 = new CLineSegment(trianglePts[0], trianglePts[1]);
            CLineSegment line1 = new CLineSegment(trianglePts[1], trianglePts[2]);
            CLineSegment line2 = new CLineSegment(trianglePts[2], trianglePts[0]);

            if (line0.PointInLine(pt) || line1.PointInLine(pt) || line2.PointInLine(pt))
            {
                bIn = true;
            }
            else             //point is not in the lines
            {
                double dblArea0 = CPolygon.PolygonArea(new Vector2d[] { trianglePts[0], trianglePts[1], pt });
                double dblArea1 = CPolygon.PolygonArea(new Vector2d[] { trianglePts[1], trianglePts[2], pt });
                double dblArea2 = CPolygon.PolygonArea(new Vector2d[] { trianglePts[2], trianglePts[0], pt });

                if (dblArea0 > 0)
                {
                    if ((dblArea1 > 0) && (dblArea2 > 0))
                    {
                        bIn = true;
                    }
                }
                else if (dblArea0 < 0)
                {
                    if ((dblArea1 < 0) && (dblArea2 < 0))
                    {
                        bIn = true;
                    }
                }
            }
            return(bIn);
        }
Ejemplo n.º 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;
            MyVector2    newStartPoint = new MyVector2();
            MyVector2    newEndPoint   = new MyVector2();

            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);
        }