Esempio n. 1
0
        private void clipBtn_Click(object sender, RoutedEventArgs e)
        {
            CGPolygon     polygon  = new CGPolygon(PolygonPoints);
            List <CGLine> segments = new List <CGLine>();

            foreach (var l in this.Lines)
            {
                Point  a = new Point(l.X1, l.Y1);
                Point  b = new Point(l.X2, l.Y2);
                CGLine S = new CGLine(a, b);
                segments.Add(S);
            }

            List <Point> pList = new List <Point>();


            var x = polygon.Clip(segments);

            foreach (var item in x)
            {
                Line ln = new Line();
                ln.X1 = item.A.X;
                ln.Y1 = item.A.Y;

                ln.X2              = item.B.X;
                ln.Y2              = item.B.Y;
                ln.Stroke          = Brushes.Pink;
                ln.StrokeThickness = 2;
                mainContainer.Children.Add(ln);
            }
        }
Esempio n. 2
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        public double IntersectionParameter(CGLine that)
        {
            var edge = that;

            var segmentToEdge = edge.A.Substract(this.A);
            var segmentDir    = this.Direction;
            var edgeDir       = edge.Direction;

            var t = edgeDir.CrossProduct(segmentToEdge) / edgeDir.CrossProduct(segmentDir);

            if (double.IsNaN(t))
            {
                t = 0;
            }

            return(t);
        }
Esempio n. 3
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        private CGLine ClipLine(CGLine line)
        {
            double tE = 0, tL = 1;
            var    dir = line.Direction;
            Point  nL;
            bool   PE = false;

            foreach (var edge in this.Edges)
            {
                nL = edge.Normal;
                var t = line.IntersectionParameter(edge);

                double slope = nL.DotProduct(dir);
                PE = (slope < 0 ? true : false);

                //potentionally entering
                if (PE)
                {
                    //Choose for parameter tE the largest t ≤ 1 from the PE set
                    if (t > tE)
                    {
                        tE = t;
                    }

                    //potentionally leaving
                }
                else
                {
                    //Choose for parameter tL the smallest t ≥ 0 from the PL set
                    if (t < tL)
                    {
                        tL = t;
                    }
                }
            }

            //Line is discarded if tE > tL
            if (tE > tL)
            {
                return(null);
            }

            //Clipped line is defined by [tE , tL]
            return(line.Morph(tE, tL));
        }
Esempio n. 4
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        public List <CGLine> Clip(List <CGLine> lines)
        {
            if (!this.IsConvex())
            {
                this.Points.Reverse();
            }

            var clippedLines = new List <CGLine>();

            foreach (var line in lines)
            {
                CGLine clippedSegment = this.ClipLine(line);
                if (clippedSegment != null)
                {
                    clippedLines.Add(clippedSegment);
                }
            }

            return(clippedLines);
        }