void R2Vector::
Mirror(const R2Line& line)
{
// Mirror vector across line
double d = Dot(line.Normal());
*this += line.Normal() * (-2.0 * d);
}
void R2Point::
Mirror(const R2Line& line)
{
// Mirror point across line
double d = R2SignedDistance(*this, line);
*this += line.Normal() * (-2.0 * d);
}
void R2Line::
Project(const R2Line& line)
{
// Project line onto another line
*this = line;
if (Vector().Dot(line.Vector()) < 0.0) Flip();
}
RNLength R2SignedDistance(const R2Line& line, const R2Box& box)
{
// Return signed distance from line to box
RNQuadrant quadrant = line.Normal().Quadrant();
RNScalar d1 = R2SignedDistance(line, box.Corner(~quadrant & 0x3));
if (RNIsPositiveOrZero(d1)) return d1;
RNScalar d2 = R2SignedDistance(line, box.Corner(quadrant));
if (RNIsNegative(d2)) return d2;
else return 0.0;
}
RNLength R2SignedDistance(const R2Line& line1, const R2Line& line2)
{
// Return signed distance from line to line
RNScalar dot = line1.Vector().Dot(line2.Vector());
if (RNIsEqual(dot, 1.0)) return (line1.C() - line2.C());
else if (RNIsEqual(dot, -1.0)) return (line1.C() + line2.C());
else return 0.0;
}
RNLength R2Distance(const R2Point& point, const R2Line& line)
{
// Return distance from point to line
RNLength d = point.X() * line.A() + point.Y() * line.B() + line.C();
return (d < 0.0) ? -d : d;
}
RNLength R2SignedDistance(const R2Line& line, const R2Point& point)
{
// Return signed distance from point to line
return (point.X()*line.A() + point.Y()*line.B() + line.C());
}
