public bool IsPointInside(Coordonnees toCheck)
{
if (IsValid())
{
double sumAngle = 0;
for (int i = 1; i <= NbPoints; i++)
{
ZZCoordinate previousPoint = (ZZCoordinate)Coordonnees[i - 1], anglePoint = (ZZCoordinate)toCheck, nextPoint = (ZZCoordinate)Coordonnees[i % NbPoints];
double alpha = ZZMath.AngleFrom3Points(previousPoint, anglePoint, nextPoint);
double dx = anglePoint.X - previousPoint.X, dy = anglePoint.Y - previousPoint.Y;
int sign = 1;
if (dx == 0) // Vertical line
{
if (dy > 0) // The line goes upward
{
if (nextPoint.X > previousPoint.X)
{
sign = -1;
}
}
else // The line goes downward
{
if (nextPoint.X < previousPoint.X)
{
sign = -1;
}
}
}
else
{
double m = dy / dx, p = previousPoint.Y - m * previousPoint.X;
double slopeAngle = ZZMath.SlopeAngle(previousPoint, anglePoint);
if (slopeAngle < 90 || slopeAngle > 270) // The point needs to be below the line
{
if (nextPoint.Y < m * nextPoint.Y + p)
{
sign = -1;
}
}
else // The point needs to be above the line
{
if (nextPoint.Y > m * nextPoint.Y + p)
{
sign = -1;
}
}
}
sumAngle += sign * alpha;
}
Console.WriteLine(sumAngle);
return(sumAngle == 360); // To be inside, the total of the angles needs to equal 360
}
return(false);
}
public bool IsPointInside(Coordonnees toCheck)
{
if (IsValid())
{
double sumAngle = 0;
for (int i = 1; i <= NbPoints; i++)
{
ZZCoordinate previousPoint = (ZZCoordinate)Coordonnees[i - 1], anglePoint = (ZZCoordinate)toCheck, nextPoint = (ZZCoordinate)Coordonnees[i % NbPoints];
double alpha = ZZMath.AngleFrom3Points(previousPoint, anglePoint, nextPoint);
double dx = anglePoint.X - previousPoint.X, dy = anglePoint.Y - previousPoint.Y;
int sign = 1;
if (dx == 0) // Vertical line
{
if (dy > 0) // The line goes upward
{
if (nextPoint.X > previousPoint.X)
{
sign = -1;
}
}
else // The line goes downward
{
if (nextPoint.X < previousPoint.X)
{
sign = -1;
}
}
}
else
{
double m = dy / dx, p = previousPoint.Y - m * previousPoint.X;
double slopeAngle = ZZMath.SlopeAngle(anglePoint, previousPoint);
double fx = m * nextPoint.X + p;
if (slopeAngle < 90 || slopeAngle > 270) // The point needs to be below the line
{
if (nextPoint.Y > fx)
{
sign = -1;
}
}
else // The point needs to be above the line
{
if (nextPoint.Y < fx)
{
sign = -1;
}
}
}
sumAngle += sign * alpha;
}
return((sumAngle > 359.9 && sumAngle < 360.1) || (sumAngle < -359.9 && sumAngle > -360.1)); // To be inside, the total of the angles needs to be above 359.9 or below 359.9, depending on the rotation sense made when creating the polygon (basicly == 360 but double precision doesn't always makes it work)
}
return(false);
}
private bool IsValid()
{
if (NbPoints >= 3) // Is at least a triangle, 3 coordinates
{
for (int i = 0; i < NbPoints; i++)
{
ZZCoordinate previousPoint = (ZZCoordinate)Coordonnees[ZZFunctions.nmod(i - 1, NbPoints)], anglePoint = (ZZCoordinate)Coordonnees[i], nextPoint = (ZZCoordinate)Coordonnees[(i + 1) % NbPoints];
double alpha = ZZMath.AngleFrom3Points(previousPoint, anglePoint, nextPoint);
if (alpha == 0)
{
return(false); // The angle formed by the 3 points isn't 0 degrees
}
}
return(true);
}
return(false);
}
public Polygon Extend(double extentionSize)
{
if (IsValid())
{
List <Coordonnees> newCoordCollection = new List <Coordonnees>();
for (int i = 0; i < NbPoints; i++)
{
ZZCoordinate previousPoint = (ZZCoordinate)Coordonnees[ZZFunctions.nmod(i - 1, NbPoints)], anglePoint = (ZZCoordinate)Coordonnees[i], nextPoint = (ZZCoordinate)Coordonnees[(i + 1) % NbPoints];
double alpha = ZZMath.AngleFrom3Points(previousPoint, anglePoint, nextPoint), beta = (180 - alpha) / 2.0;
double slopeAngle = ZZMath.SlopeAngle(previousPoint, anglePoint) + beta;
double distanceToAdd = extentionSize / Math.Cos(ZZMath.ToRadians(beta));
double newX = anglePoint.X + distanceToAdd * Math.Cos(ZZMath.ToRadians(slopeAngle));
double newY = anglePoint.Y + distanceToAdd * Math.Sin(ZZMath.ToRadians(slopeAngle));
newCoordCollection.Add(new Coordonnees(newX, newY));
}
return(new Polygon(newCoordCollection, BackgroundColor, BorderColor, Oppacity));
}
return(this);
}