private void DrawPointGizmos()
{
if (fan.Length <= 0f)
{
return;
}
var col = color;
if (pointObj != null && fan.ContainPoint(pointObj.point))
{
col = Color.red;
}
else if (rectObj != null && fan.IntersectWith(rectObj.rect))
{
col = Color.red;
}
else if (circleObj != null && fan.IntersectWith(circleObj.circle))
{
col = Color.red;
}
GizmosUtil.DrawFan(fan, col, mesh);
}
private void OnDrawGizmos()
{
bool isRectInersctWithCircle = m_circle.IntersectWith(m_rect);
bool isFanIntersectWithCircle = m_fan.IntersectWith(m_circle);
bool isFanIntersectWithRect = m_fan.IntersectWith(m_rect);
Color rectColor;
if (isRectInersctWithCircle)
{
rectColor = m_intersectCol;
}
else
{
rectColor = m_colors[0];
}
GizmosUtils.DrawRectSolid(m_rect, rectColor);
GizmosUtils.DrawRect(m_rect.Extand(m_circle.m_radius, m_circle.m_radius), rectColor);
Color circleColor;
if (isRectInersctWithCircle || isFanIntersectWithCircle)
{
circleColor = m_intersectCol;
}
else
{
circleColor = m_colors[1];
}
GizmosUtils.DrawCircle(m_circle, circleColor);
Color fanColor;
if (isFanIntersectWithCircle || isFanIntersectWithRect)
{
fanColor = m_intersectCol;
}
else
{
fanColor = m_colors[2];
}
GizmosUtils.DrawFan(m_fan, fanColor);
if (m_circle.ContainPoint(m_point) || m_rect.ContainPoint(m_point) || m_fan.ContainPoint(m_point))
{
Gizmos.color = m_intersectCol;
}
else
{
Gizmos.color = m_colors[3];
}
GizmosUtils.DrawPoint(m_point);
}
public static bool IntersectWith(Fan _fan, Rectangle _rect)
{
//条件一：矩形四个角落的判断
var coners = _rect.Coners;
for (int i = 0; i < 4; i++)
{
if (_fan.ContainPoint(coners[i]))
{
return(true);
}
}
//条件二：扇形的两个边点落在矩形内
if (_rect.ContainPoint(_fan.Left))
{
return(true);
}
if (_rect.ContainPoint(_fan.Right))
{
return(true);
}
//条件三：彼此中心点
if (_rect.ContainPoint(_fan.m_center))
{
return(true);
}
if (_fan.ContainPoint(_rect.m_center))
{
return(true);
}
//条件四，矩形的边和弧相交
var begin = _fan.m_center;
var end = _rect.m_center;
var v = end - begin;
//圆的方程（x - xc）^2 + ( y - yc ) ^ 2 = r^2
//线段的方程
// x = v.x * t + begin.x
// y = v.y * t + begin.y
//求扇形圆心和矩形的中心线段
//把线段方程代入可以得到一个二次方程
//把它化为形如 a * x^2 + 2 * b * x + c = 0
//如果 x 有解，说明相交，无解
//b^2 - a *c >= 0，有解
var dx = _fan.m_center.x - begin.x;
var dy = _fan.m_center.y - begin.y;
var sqr_r = _fan.Length * _fan.Length;
var a = v.x * v.x + v.y * v.y;
var b = -(dx * v.x + dy * v.y);
var c = dx * dx + dy * dy - sqr_r;
var d = b * b - a * c;
Color old = Gizmos.color;
Gizmos.color = Color.white;
Gizmos.DrawLine(begin.ToXZ(), end.ToXZ());
Gizmos.color = old;
if (d >= 0) // 有解
{
var t = (-b + Mathf.Sqrt(d)) / a;
var x = v.x * t + begin.x;
var y = v.y * t + begin.y;
var point = new Vector2(x, y);
GizmosUtils.DrawPoint(point);
//扇形只会包含其中一个解
var left = _fan.Left;
var right = _fan.Right;
if (_rect.ContainPoint(point) && point.Between(_fan.m_center, left, right))
{
return(true);
}
//另一个方向
t = (-b + Mathf.Sqrt(d)) / a;
x = v.x * t + begin.x;
y = v.y * t + begin.y;
point = new Vector2(x, y);
GizmosUtils.DrawPoint(point);
if (_rect.ContainPoint(point) && point.Between(_fan.m_center, left, right))
{
return(true);
}
}
else
{
//无解，说明要么扇形包含矩形中心，要么矩形包含扇形圆心，否则就不相交
}
return(false);
}
