예제 #1
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(CPoint2D[] trianglePts, CPoint2D 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 (pt.InLine(line0) || pt.InLine(line1) ||
                pt.InLine(line2))
            {
                bIn = true;
            }
            else             //point is not in the lines
            {
                double dblArea0 = CPolygon.PolygonArea(new CPoint2D[] { trianglePts[0], trianglePts[1], pt });
                double dblArea1 = CPolygon.PolygonArea(new CPoint2D[] { trianglePts[1], trianglePts[2], pt });
                double dblArea2 = CPolygon.PolygonArea(new CPoint2D[] { 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);
        }
예제 #2
0
        /*******************************************************
        *  To cut an ear from polygon to make ears and an updated polygon:
        *******************************************************/

        public void CutEar()
        {
            CPolygon polygon = new CPolygon(m_aUpdatedPolygonVertices);
            bool     bFinish = false;

            //if (polygon.GetPolygonType()==PolygonType.Convex) //don't have to cut ear
            //	bFinish=true;

            if (m_aUpdatedPolygonVertices.Length == 3)             //triangle, don't have to cut ear
            {
                bFinish = true;
            }

            CPoint2D pt = new CPoint2D();

            while (bFinish == false)             //UpdatedPolygon
            {
                int  i         = 0;
                bool bNotFound = true;
                while (bNotFound && (i < m_aUpdatedPolygonVertices.Length))                 //loop till find an ear
                {
                    pt = m_aUpdatedPolygonVertices[i];
                    if (IsEarOfUpdatedPolygon(pt))
                    {
                        bNotFound = false;                         //got one, pt is an ear
                    }
                    else
                    {
                        i++;
                    }
                }                 //bNotFount
                //An ear found:}
                if (pt != null)
                {
                    UpdatePolygonVertices(pt);
                }

                polygon = new CPolygon(m_aUpdatedPolygonVertices);
                //if ((polygon.GetPolygonType()==PolygonType.Convex)
                //	&& (m_aUpdatedPolygonVertices.Length==3))
                if (m_aUpdatedPolygonVertices.Length == 3)
                {
                    bFinish = true;
                }
            }             //bFinish=false
            SetPolygons();
        }
예제 #3
0
        /****************************************************
         * To fill m_aUpdatedPolygonVertices array with input array.
         *
         * m_aUpdatedPolygonVertices is a working array that will
         * be updated when an ear is cut till m_aUpdatedPolygonVertices
         * makes triangle (a convex polygon).
         ******************************************************/

        private void SetUpdatedPolygonVertices()
        {
            int nVertices = m_aInputVertices.Length;

            m_aUpdatedPolygonVertices = new CPoint2D[nVertices];

            for (int i = 0; i < nVertices; i++)
            {
                m_aUpdatedPolygonVertices[i] = m_aInputVertices[i];
            }

            //m_aUpdatedPolygonVertices should be in count clock wise
            if (CPolygon.PointsDirection(m_aUpdatedPolygonVertices)
                == PolygonDirection.Clockwise)
            {
                CPolygon.ReversePointsDirection(m_aUpdatedPolygonVertices);
            }
        }
예제 #4
0
        /*******************************************************
        To cut an ear from polygon to make ears and an updated polygon:
        *******************************************************/
        public void CutEar()
        {
            CPolygon polygon = new CPolygon(m_aUpdatedPolygonVertices);
            bool bFinish = false;

            //if (polygon.GetPolygonType()==PolygonType.Convex) //don't have to cut ear
            //	bFinish=true;

            if (m_aUpdatedPolygonVertices.Length == 3) //triangle, don't have to cut ear
            {
                bFinish = true;
            }

            CPoint2D pt = new CPoint2D();
            while (bFinish == false) //UpdatedPolygon
            {
                int i = 0;
                bool bNotFound = true;
                while (bNotFound && (i < m_aUpdatedPolygonVertices.Length)) //loop till find an ear
                {
                    pt = m_aUpdatedPolygonVertices[i];
                    if (IsEarOfUpdatedPolygon(pt)) {
                        bNotFound = false; //got one, pt is an ear
                    }
                    else {
                        i++;
                    }
                } //bNotFount
                //An ear found:}
                if (pt != null) {
                    UpdatePolygonVertices(pt);
                }

                polygon = new CPolygon(m_aUpdatedPolygonVertices);
                //if ((polygon.GetPolygonType()==PolygonType.Convex)
                //	&& (m_aUpdatedPolygonVertices.Length==3))
                if (m_aUpdatedPolygonVertices.Length == 3) {
                    bFinish = true;
                }
            } //bFinish=false
            SetPolygons();
        }
예제 #5
0
        /****************************************************************
         * To check whether the Vertex is an ear or not based updated Polygon vertices
         *
         * ref. www-cgrl.cs.mcgill.ca/~godfried/teaching/cg-projects/97/Ian
         * /algorithm1.html
         *
         * If it is an ear, return true,
         * If it is not an ear, return false;
         *****************************************************************/

        private bool IsEarOfUpdatedPolygon(CPoint2D vertex)
        {
            CPolygon polygon = new CPolygon(m_aUpdatedPolygonVertices);

            if (polygon.PolygonVertex(vertex))
            {
                bool bEar = true;
                if (polygon.PolygonVertexType(vertex)
                    == VertexType.ConvexPoint)
                {
                    CPoint2D pi = vertex;
                    CPoint2D pj = polygon.PreviousPoint(vertex);                 //previous vertex
                    CPoint2D pk = polygon.NextPoint(vertex);                     //next vertex

                    for (int i = m_aUpdatedPolygonVertices.GetLowerBound(0); i < m_aUpdatedPolygonVertices.GetUpperBound(0); i++)
                    {
                        CPoint2D pt = m_aUpdatedPolygonVertices[i];
                        if (!(pt.EqualsPoint(pi) || pt.EqualsPoint(pj) || pt.EqualsPoint(pk)))
                        {
                            if (TriangleContainsPoint(new CPoint2D[] { pj, pi, pk }, pt))
                            {
                                bEar = false;
                            }
                        }
                    }
                }                 //ThePolygon.getVertexType(Vertex)=ConvexPt
                else              //concave point
                {
                    bEar = false; //not an ear/
                }
                return(bEar);
            }
            else             //not a polygon vertex;
            {
                Trace.WriteLine("IsEarOfUpdatedPolygon: " + "Not a polygon vertex");
                return(false);
            }
        }
예제 #6
0
        /********************************************************
         * To update m_aUpdatedPolygonVertices:
         * Take out Vertex from m_aUpdatedPolygonVertices array, add 3 points
         * to the m_aEars
         **********************************************************/

        private void UpdatePolygonVertices(CPoint2D vertex)
        {
            ArrayList alTempPts = new ArrayList();

            for (int i = 0; i < m_aUpdatedPolygonVertices.Length; i++)
            {
                if (vertex.EqualsPoint(m_aUpdatedPolygonVertices[i]))                 //add 3 pts to FEars
                {
                    CPolygon polygon = new CPolygon(m_aUpdatedPolygonVertices);
                    CPoint2D pti     = vertex;
                    CPoint2D ptj     = polygon.PreviousPoint(vertex);      //previous point
                    CPoint2D ptk     = polygon.NextPoint(vertex);          //next point

                    CPoint2D[] aEar = new CPoint2D[3];                     //3 vertices of each ear
                    aEar[0] = ptj;
                    aEar[1] = pti;
                    aEar[2] = ptk;

                    m_alEars.Add(aEar);
                }
                else
                {
                    alTempPts.Add(m_aUpdatedPolygonVertices[i]);
                }                 //not equal points
            }

            if (m_aUpdatedPolygonVertices.Length - alTempPts.Count == 1)
            {
                int nLength = m_aUpdatedPolygonVertices.Length;
                m_aUpdatedPolygonVertices = new CPoint2D[nLength - 1];

                for (int i = 0; i < alTempPts.Count; i++)
                {
                    m_aUpdatedPolygonVertices[i] = (CPoint2D)alTempPts[i];
                }
            }
        }
예제 #7
0
        /********************************************************
        To update m_aUpdatedPolygonVertices:
        Take out Vertex from m_aUpdatedPolygonVertices array, add 3 points
        to the m_aEars
        **********************************************************/
        private void UpdatePolygonVertices(CPoint2D vertex)
        {
            ArrayList alTempPts = new ArrayList();

            for (int i = 0; i < m_aUpdatedPolygonVertices.Length; i++) {
                if (vertex.EqualsPoint(m_aUpdatedPolygonVertices[i])) //add 3 pts to FEars
                {
                    CPolygon polygon = new CPolygon(m_aUpdatedPolygonVertices);
                    CPoint2D pti = vertex;
                    CPoint2D ptj = polygon.PreviousPoint(vertex); //previous point
                    CPoint2D ptk = polygon.NextPoint(vertex); //next point

                    CPoint2D[] aEar = new CPoint2D[3]; //3 vertices of each ear
                    aEar[0] = ptj;
                    aEar[1] = pti;
                    aEar[2] = ptk;

                    m_alEars.Add(aEar);
                }
                else {
                    alTempPts.Add(m_aUpdatedPolygonVertices[i]);
                } //not equal points
            }

            if (m_aUpdatedPolygonVertices.Length - alTempPts.Count == 1) {
                int nLength = m_aUpdatedPolygonVertices.Length;
                m_aUpdatedPolygonVertices = new CPoint2D[nLength - 1];

                for (int i = 0; i < alTempPts.Count; i++) {
                    m_aUpdatedPolygonVertices[i] = (CPoint2D) alTempPts[i];
                }
            }
        }
예제 #8
0
        /****************************************************************
        To check whether the Vertex is an ear or not based updated Polygon vertices

        ref. www-cgrl.cs.mcgill.ca/~godfried/teaching/cg-projects/97/Ian
        /algorithm1.html

        If it is an ear, return true,
        If it is not an ear, return false;
        *****************************************************************/
        private bool IsEarOfUpdatedPolygon(CPoint2D vertex)
        {
            CPolygon polygon = new CPolygon(m_aUpdatedPolygonVertices);

            if (polygon.PolygonVertex(vertex)) {
                bool bEar = true;
                if (polygon.PolygonVertexType(vertex)
                    == VertexType.ConvexPoint) {
                    CPoint2D pi = vertex;
                    CPoint2D pj = polygon.PreviousPoint(vertex); //previous vertex
                    CPoint2D pk = polygon.NextPoint(vertex); //next vertex

                    for (int i = m_aUpdatedPolygonVertices.GetLowerBound(0); i < m_aUpdatedPolygonVertices.GetUpperBound(0); i++) {
                        CPoint2D pt = m_aUpdatedPolygonVertices[i];
                        if (!(pt.EqualsPoint(pi) || pt.EqualsPoint(pj) || pt.EqualsPoint(pk))) {
                            if (TriangleContainsPoint(new CPoint2D[] {pj, pi, pk}, pt)) {
                                bEar = false;
                            }
                        }
                    }
                } //ThePolygon.getVertexType(Vertex)=ConvexPt
                else //concave point
                {
                    bEar = false; //not an ear/
                }
                return bEar;
            }
            else //not a polygon vertex;
            {
                Trace.WriteLine("IsEarOfUpdatedPolygon: " + "Not a polygon vertex");
                return false;
            }
        }