public bool PolygonClip(GraphPolygon Source, ref GraphPolygon Result, GraphPolygon Clipper)
{
if ((Clipper.Count < 3) || (Clipper.Convexity == -1))
{
MessageBox.Show("Polygon is not convex");
return(false);
}
int i, j;
PointD R;
PointD S = new PointD(), F = new PointD();
List <PointD> TempSource = new List <PointD>();
if (curstep == 0)
{
Result.Vertexes = new List <PointD>(Source.Vertexes);
}
Result.Closed = true;
int t;
if (Clipper.Square > 0)
{
t = 1;
}
else
{
t = -1;
}
Clipper.Add(Clipper[0]);
for (i = curstep; i < Clipper.Count - 1; i++)
{
TempSource.Clear();
F = Result.Vertexes[0]; // end vertex
S = Result.Vertexes[0]; // begin vertex
if (Geom2d.Square(S, Clipper.Vertexes[i], Clipper.Vertexes[i + 1]) * t >= 0)
{
TempSource.Add(S);
}
for (j = 1; j < Result.Vertexes.Count; j++)
{
if (Geom2d.SegmentLineIntersect(S, Result.Vertexes[j], Clipper.Vertexes[i], Clipper.Vertexes[i + 1], out R) == 1)
{
TempSource.Add(R);
}
S = Result.Vertexes[j];
if (Geom2d.Square(S, Clipper.Vertexes[i], Clipper.Vertexes[i + 1]) * t > 0)
{
TempSource.Add(S);
}
}
if ((TempSource.Count != 0) && (Geom2d.SegmentLineIntersect(S, F, Clipper.Vertexes[i], Clipper.Vertexes[i + 1], out R) == 1))
{
TempSource.Add(R);
}
Result.Clear();
Result.Vertexes.AddRange(TempSource);
if (step)
{
curstep = i + 1;
step = false;
Clipper.RemoveLast();
return(true);
}
}
Clipper.RemoveLast();
return(true);
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
Brush brush = new SolidBrush(pnlBackground.BackColor);
G.FillRectangle(brush, 0, 0, B.Width, B.Height);
PointD P = new PointD(e.X, e.Y);
if (rbIntercept.Checked)
{
if (e.Button == MouseButtons.Left)
{
if (Polygons[Polygons.Count - 1].Count != 0)
{
if (IsShiftDown() == true)
{
PointD PT = new PointD();
PT = Polygons[Polygons.Count - 1][Polygons[Polygons.Count - 1].Count - 1];
if (Math.Abs(e.X - PT.X) < Math.Abs(e.Y - PT.Y))
{
P.X = PT.X;
P.Y = e.Y;
}
else
{
P.X = e.X;
P.Y = PT.Y;
}
}
}
Polygons[Polygons.Count - 1].Add(P);
//Polygons[Polygons.Count-1].DrawLastSegment();
}
else
if (e.Button == MouseButtons.Right)
{
Polygons[Polygons.Count - 1].Closed = true;
//Polygons[Polygons.Count - 1].DrawBeginEndSegment();
Polygons.Add(new GraphPolygon(B, G, new Pen(pnlLine.BackColor)));
}
}
else
{
if (e.Button == MouseButtons.Left)
{
if (ClipPolygon.Closed == true)
{
ClipPolygon.Clear();
ClipPolygon.Closed = false;
}
else
{
if ((ClipPolygon.Count >= 1) && (IsShiftDown() == true))
{
Point PT = new Point();
PT = ClipPolygon[ClipPolygon.Count - 1];
if (Math.Abs(e.X - PT.X) < Math.Abs(e.Y - PT.Y))
{
P.X = PT.X;
P.Y = e.Y;
}
else
{
P.X = e.X;
P.Y = PT.Y;
}
}
}
ClipPolygon.Add(P);
ClipPolygon.UpdatePolygon();
}
else
if (e.Button == MouseButtons.Right)
{
//ClipPolygon.Add(ClipPolygon[0]);
ClipPolygon.Closed = true;
}
//ClipPolygon.DrawLastSegment();
if (ClipPolygon.Square > 0)
{
lblBypass.Text = "Против час. стрелки";
}
else
if (ClipPolygon.Square < 0)
{
lblBypass.Text = "По час. стрелке";
}
else
{
lblBypass.Text = "---";
}
if (ClipPolygon.Convexity > 0)
{
lblConvex.Text = "Да";
}
else
if (ClipPolygon.Convexity < 0)
{
lblConvex.Text = "Нет";
}
else
{
lblConvex.Text = "---";
}
if (ClipPolygon.SelfIntersection > 0)
{
lblSelfintersect.Text = "Есть";
}
else
if (ClipPolygon.SelfIntersection < 0)
{
lblSelfintersect.Text = "Нет";
}
else
{
lblSelfintersect.Text = "---";
}
}
UpdateAll();
//ClipAndDraw();
pictureBox1.Refresh();
}
