double bowArea(double r, point p1, point p2)
{
double d = p1.distTo(p2);
var b1 = d / 2;
double b2 = Math.Sqrt(r * r - b1 * b1);
var tg = b1 / b2;
var angle = Math.Atan(tg) * 2;
//Console.WriteLine(angle * (180 / Math.PI));
var fanA = r * r * angle / 2;
var tranA = b1 * b2;
return(fanA - tranA);
}
private double calcPass(double vstring, double hstring)
{
var x1 = vstring + r;
var x2 = x1 + g;
var y1 = hstring + r;
var y2 = y1 + g;
x1 += f;
x2 -= f;
y1 += f;
y2 -= f;
var leftBottom = new point(x1, y1);
// totally out
if (OrgPoint.distTo(leftBottom) >= flyR)
{
return(0);
}
var rightTop = new point(x2, y2);
if (rightTop.distTo(OrgPoint) <= flyR)
{
return(sqPass);
}
var rightBottom = new point(x2, y1);
bool rightBottomOut = rightBottom.distTo(OrgPoint) >= flyR;
var leftTop = new point(x1, y2);
bool leftTopOut = leftTop.distTo(OrgPoint) >= flyR;
double res = 0;
// 1
if (!rightBottomOut && !leftTopOut)
{
var p1 = new point(x2, otherCood(flyR, x2));
var p2 = new point(otherCood(flyR, y2), y2);
res += bowArea(flyR, p1, p2);
res += sqPass;
res -= ((x2 - p2.x) * (y2 - p1.y)) / 2;
}
else if (rightBottomOut && !leftTopOut)
{
var p1 = new point(otherCood(flyR, y1), y1);
var p2 = new point(otherCood(flyR, y2), y2);
res += bowArea(flyR, p1, p2);
var lx = Math.Max(p1.x, p2.x);
var sx = Math.Min(p1.x, p2.x);
res += passG * (sx - x1);
res += (passG * (lx - sx)) / 2;
}
else if (!rightBottomOut && leftTopOut)
{
var p1 = new point(x2, otherCood(flyR, x2));
var p2 = new point(x1, otherCood(flyR, x1));
res += bowArea(flyR, p1, p2);
var ly = Math.Max(p1.y, p2.y);
var sy = Math.Min(p1.y, p2.y);
res += passG * (sy - y1);
res += (passG * (ly - sy)) / 2;
}
else if (rightBottomOut && leftTopOut)
{
var p1 = new point(x1, otherCood(flyR, x1));
var p2 = new point(otherCood(flyR, y1), y1);
res += bowArea(flyR, p1, p2);
res += ((p1.y - y1) * (p2.x - x1)) / 2;
}
return(res);
}
