/// <summary>
/// Calculate the distance between the two points.
/// </summary>
public static Fixed PointToDist(Fixed fromX, Fixed fromY, Fixed toX, Fixed toY)
{
var dx = Fixed.Abs(toX - fromX);
var dy = Fixed.Abs(toY - fromY);
if (dy > dx)
{
var temp = dx;
dx = dy;
dy = temp;
}
// The code below to avoid division by zero is based on Chocolate Doom's implementation.
Fixed frac;
if (dx != Fixed.Zero)
{
frac = dy / dx;
}
else
{
frac = Fixed.Zero;
}
var angle = (Trig.TanToAngle((uint)frac.Data >> fracToSlopeShift) + Angle.Ang90);
// Use as cosine.
var dist = dx / Trig.Sin(angle);
return(dist);
}
/// <summary>
/// Calculate the angle of the line passing through the two points.
/// </summary>
public static Angle PointToAngle(Fixed fromX, Fixed fromY, Fixed toX, Fixed toY)
{
var x = toX - fromX;
var y = toY - fromY;
if (x == Fixed.Zero && y == Fixed.Zero)
{
return(Angle.Ang0);
}
if (x >= Fixed.Zero)
{
// x >= 0
if (y >= Fixed.Zero)
{
// y >= 0
if (x > y)
{
// octant 0
return(Trig.TanToAngle(SlopeDiv(y, x)));
}
else
{
// octant 1
return(new Angle(Angle.Ang90.Data - 1) - Trig.TanToAngle(SlopeDiv(x, y)));
}
}
else
{
// y < 0
y = -y;
if (x > y)
{
// octant 8
return(-Trig.TanToAngle(SlopeDiv(y, x)));
}
else
{
// octant 7
return(Angle.Ang270 + Trig.TanToAngle(SlopeDiv(x, y)));
}
}
}
else
{
// x < 0
x = -x;
if (y >= Fixed.Zero)
{
// y >= 0
if (x > y)
{
// octant 3
return(new Angle(Angle.Ang180.Data - 1) - Trig.TanToAngle(SlopeDiv(y, x)));
}
else
{
// octant 2
return(Angle.Ang90 + Trig.TanToAngle(SlopeDiv(x, y)));
}
}
else
{
// y < 0
y = -y;
if (x > y)
{
// octant 4
return(Angle.Ang180 + Trig.TanToAngle(SlopeDiv(y, x)));
}
else
{
// octant 5
return(new Angle(Angle.Ang270.Data - 1) - Trig.TanToAngle(SlopeDiv(x, y)));
}
}
}
}