/// <summary>
/// ��鵱ǰԲ���Ƿ����ָ��ֱ��
/// </summary>
///
/// <param name="line"></param>
/// <returns></returns>
public bool Contains(Line line)
{
return Contains(line.GetX1(), line.GetY1())
&& Contains(line.GetX2(), line.GetY2());
}
public bool Intersects(Line other)
{
Vector2f lineSegmentStart = new Vector2f(other.GetX1(), other.GetY1());
Vector2f lineSegmentEnd = new Vector2f(other.GetX2(), other.GetY2());
Vector2f circleCenter = new Vector2f(GetCenterX(), GetCenterY());
Vector2f closest;
Vector2f segv = lineSegmentEnd.Cpy().Sub(lineSegmentStart);
Vector2f ptv = circleCenter.Cpy().Sub(lineSegmentStart);
float segvLength = segv.Len();
float projvl = ptv.Dot(segv) / segvLength;
if (projvl < 0)
{
closest = lineSegmentStart;
}
else if (projvl > segvLength)
{
closest = lineSegmentEnd;
}
else
{
Vector2f projv = segv.Cpy().Scale(projvl / segvLength);
closest = lineSegmentStart.Cpy().Add(projv);
}
bool intersects = circleCenter.Cpy().Sub(closest).LengthSquared() <= GetRadius()
* GetRadius();
return intersects;
}
private bool Intersects(RectBox other)
{
RectBox box = other;
Circle circle = this;
if (box.Contains(x + radius, y + radius))
{
return true;
}
float x1 = box.GetX();
float y1 = box.GetY();
float x2 = box.GetX() + box.GetWidth();
float y2 = box.GetY() + box.GetHeight();
Line[] lines = new Line[4];
lines[0] = new Line(x1, y1, x2, y1);
lines[1] = new Line(x2, y1, x2, y2);
lines[2] = new Line(x2, y2, x1, y2);
lines[3] = new Line(x1, y2, x1, y1);
float r2 = circle.GetRadius() * circle.GetRadius();
Vector2f pos = new Vector2f(circle.GetCenterX(), circle.GetCenterY());
for (int i = 0; i < 4; i++)
{
float dis = lines[i].DistanceSquared(pos);
if (dis < r2)
{
return true;
}
}
return false;
}
public bool Includes(float x_0, float y_1)
{
if (points.Length == 0) {
return false;
}
CheckPoints();
Line testLine = new Line(0, 0, 0, 0);
Vector2f pt = new Vector2f(x_0, y_1);
for (int i = 0; i < points.Length; i += 2) {
int n = i + 2;
if (n >= points.Length) {
n = 0;
}
testLine.Set(points[i], points[i + 1], points[n], points[n + 1]);
if (testLine.On(pt)) {
return true;
}
}
return false;
}
public bool Intersect(Line other, bool limit, Vector2f result)
{
float dx1 = end.GetX() - start.GetX();
float dx2 = other.end.GetX() - other.start.GetX();
float dy1 = end.GetY() - start.GetY();
float dy2 = other.end.GetY() - other.start.GetY();
float denom = (dy2 * dx1) - (dx2 * dy1);
if (denom == 0) {
return false;
}
float ua = (dx2 * (start.GetY() - other.start.GetY()))
- (dy2 * (start.GetX() - other.start.GetX()));
ua /= denom;
float ub = (dx1 * (start.GetY() - other.start.GetY()))
- (dy1 * (start.GetX() - other.start.GetX()));
ub /= denom;
if ((limit) && ((ua < 0) || (ua > 1) || (ub < 0) || (ub > 1))) {
return false;
}
float u = ua;
float ix = start.GetX() + (u * (end.GetX() - start.GetX()));
float iy = start.GetY() + (u * (end.GetY() - start.GetY()));
result.Set(ix, iy);
return true;
}
public Vector2f Intersect(Line other, bool limit)
{
Vector2f temp = new Vector2f();
if (!Intersect(other, limit, temp)) {
return null;
}
return temp;
}
public Vector2f Intersect(Line other)
{
return Intersect(other, false);
}
public Vector2f Intersect(Line other)
{
return(Intersect(other, false));
}