// from http://www.geeksforgeeks.org/check-if-two-given-line-segments-intersect/
// Given three colinear points p, q, r, the function checks if
// point q lies on line segment 'pr'
private bool onSegment(Vertice p, Vertice q, Vertice r)
{
if (p.X <= Math.Max(p.X, r.X) && q.X >= Math.Max(p.X, r.X) &&
q.Y <= Math.Min(p.Y, r.Y) && q.Y >= Math.Min(p.Y, r.Y))
return true;
return false;
}
// To find orientation of ordered triplet (p, q, r).
// The function returns following values
// 0 --> p, q and r are colinear
// 1 --> Clockwise
// 2 --> Counterclockwise
int orientation(Vertice p, Vertice q, Vertice r)
{
// See http://www.geeksforgeeks.org/orientation-3-ordered-points/
// for details of below formula.
double val = (q.Y - p.Y) * (r.X - q.X) -
(q.X - p.X) * (r.Y - q.Y);
if (val == 0)
{
return 0; // colinear
}
return (val > 0) ? 1 : 2; // clock or counterclock wise
}
// The main function that returns true if line segment 'p1q1'
// and 'p2q2' intersect.
bool doIntersect(Vertice p1, Vertice q1, Vertice p2, Vertice q2)
{
// Find the four orientations needed for general and
// special cases
int o1 = orientation(p1, q1, p2);
int o2 = orientation(p1, q1, q2);
int o3 = orientation(p2, q2, p1);
int o4 = orientation(p2, q2, q1);
// General case
if (o1 != o2 && o3 != o4)
return true;
// Special Cases
// p1, q1 and p2 are colinear and p2 lies on segment p1q1
if (o1 == 0 && onSegment(p1, p2, q1)) return true;
// p1, q1 and p2 are colinear and q2 lies on segment p1q1
if (o2 == 0 && onSegment(p1, q2, q1)) return true;
// p2, q2 and p1 are colinear and p1 lies on segment p2q2
if (o3 == 0 && onSegment(p2, p1, q2)) return true;
// p2, q2 and q1 are colinear and q1 lies on segment p2q2
if (o4 == 0 && onSegment(p2, q1, q2)) return true;
return false; // Doesn't fall in any of the above cases
}
private bool findNext(Vertice Start, Vertice End, List<Vertice> path)
{
Vertice found = null;
double closestDistance = 0, distance;
List<Vertice> nonIntersects = new List<Vertice>();
for (int i = 0; i < Vertices.Count; i++)
{
if (checkAgainstAll(Start, Vertices[i]) && !path.Contains(Vertices[i]))
{
nonIntersects.Add(Vertices[i]);
}
}
for (int j = 0; j < nonIntersects.Count; j++)
{
distance = Math.Sqrt((Math.Pow(Math.Abs(End.X - nonIntersects[j].X), 2) + Math.Pow(Math.Abs(End.Y - nonIntersects[j].Y), 2)));
if ((j == 0) || (distance < closestDistance))
{
found = nonIntersects[j];
closestDistance = distance;
}
}
if (nonIntersects.Count == 0) {
return false;
}
else
{
path.Add(found);
return true;
}
}
private bool checkAgainstAll(Vertice Looking, Vertice Goal)
{
bool retVal = true;
Pen penTg = new Pen(Color.Green);
penTg.Width = 2;
Pen penTr = new Pen(Color.Red);
penTr.Width = 2;
foreach (Guard guard in Guards)
{
if (guard.Validated) {
if (!guard.belongsTo(Looking) && !guard.belongsTo(Goal) && doIntersect(Looking, Goal, guard.VerticeS, guard.VerticeE))
{
if (!isDebug) { return false; }
graphicsObject.DrawLine(penTr, 5 + (int)(guard.VerticeS.X * graphicsScale), ((int)((yMax - guard.VerticeS.Y) * graphicsScale) + 10),
5 + (int)(guard.VerticeE.X * graphicsScale), ((int)((yMax - guard.VerticeE.Y) * graphicsScale) + 10));
retVal = false;
}
else
{
graphicsObject.DrawLine(penTg, 5 + (int)(guard.VerticeS.X * graphicsScale), ((int)((yMax - guard.VerticeS.Y) * graphicsScale) + 10),
5 + (int)(guard.VerticeE.X * graphicsScale), ((int)((yMax - guard.VerticeE.Y) * graphicsScale) + 10));
}
}
if (isDebug) {
Application.DoEvents();
Thread.Sleep(50);
}
}
return retVal;
}
public bool checkVisibles(Vertice Start, Vertice End, out List<Vertice> path)
{
if (Vertices == null || Guards == null) { path = null; return false; }
Vertices.Add(End);
path = new List<Vertice>();
path.Add(Start);
int i = 0;
do
{
findNext(path[i], End, path);
i++;
} while ((i < path.Count) && (path[i] != End));
Pen penPr = new Pen(Color.Purple);
penPr.Width = 1;
for (i = 0; i < path.Count - 1; i++)
{
graphicsObject.DrawLine(penPr, 5 + (int)(path[i].X * graphicsScale), ((int)((yMax - path[i].Y) * graphicsScale) + 10),
5 + (int)(path[i + 1].X * graphicsScale), ((int)((yMax - path[i + 1].Y) * graphicsScale) + 10));
}
Vertices.Remove(End);
// Vertices.Remove(Start);
return true;
}
public Vertice addVertice(Vertice vertice)
{
if (Vertices == null) { Vertices = new SortableBindingList<Vertice>(); }
foreach (Vertice vertice_ in Vertices)
{
if ((vertice_.X == vertice.X) && (vertice_.Y == vertice.Y)) { return vertice_; }
}
Vertices.Add(vertice);
return vertice;
}
public bool setRange(double x1, double y1, double x2, double y2)
{
if ((x1 > parent.xMax) || (x1 < parent.xMin) ||
(x2 > parent.xMax) || (x2 < parent.xMin) ||
(y1 > parent.yMax) || (y1 < parent.yMin) ||
(y2 > parent.yMax) || (y2 < parent.yMin)) { return false; }
if (VerticeS == null) { verticeS = new Vertice(); }
if (VerticeE == null) { verticeE = new Vertice(); }
VerticeS.X = x1;
VerticeS.Y = y1;
VerticeE.X = x2;
VerticeE.Y = y2;
VerticeS = parent.addVertice(VerticeS);
VerticeE = parent.addVertice(VerticeE);
validated = true;
Notify("Set range");
return true;
}
public bool belongsTo(Vertice vertice)
{
if ((vertice == VerticeS) || (vertice == VerticeE)) { return true; }
return false;
}