public static bool CloseTo(double a, double b, double tolerance = .00001)
{
var epsilon =
Math.Max(Math.Max(Math.Abs(a), Math.Abs(b)) * tolerance,
tolerance); // .001% of the smaller value for the epsilon check as per MSDN reference suggestion
return(Math.Abs(a - b) <= epsilon);
}
/// <summary>
/// calculates the smallest AABB that will encompass the rotated box. The AABB is in local space.
/// </summary>
public Box2 CalcBoundingBox()
{
// https://stackoverflow.com/a/19830964
var(X0, Y0) = Box.BottomLeft;
var(X1, Y1) = Box.TopRight;
var Fi = Rotation.Theta;
var CX = (X0 + X1) / 2; //Center point
var CY = (Y0 + Y1) / 2;
var WX = (X1 - X0) / 2; //Half-width
var WY = (Y1 - Y0) / 2;
var SF = Math.Sin(Fi);
var CF = Math.Cos(Fi);
var NH = Math.Abs(WX * SF) + Math.Abs(WY * CF); //boundrect half-height
var NW = Math.Abs(WX * CF) + Math.Abs(WY * SF); //boundrect half-width
return(new Box2((float)(CX - NW), (float)(CY - NH), (float)(CX + NW), (float)(CY + NH))); //draw bound rectangle
}
