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;
}
void R2Point::
Mirror(const R2Line& line)
{
// Mirror point across line
double d = R2SignedDistance(*this, line);
*this += line.Normal() * (-2.0 * d);
}
RNLength R2Distance(const R2Point& point, const R2Halfspace& halfspace)
{
// Return distance from point to halfspace
RNScalar d = R2SignedDistance(halfspace.Line(), point);
if (RNIsNegative(d)) return -d;
else return 0.0;
}
RNLength R2Distance(const R2Span& span, const R2Halfspace& halfspace)
{
// Return distance from span to halfspace
RNScalar d = R2SignedDistance(halfspace.Line(), span);
if (RNIsNegative(d)) return -d;
else return 0.0;
}
RNLength R2Distance(const R2Ray& ray, const R2Halfspace& halfspace)
{
// Return distance from ray to halfspace
RNScalar d = R2SignedDistance(halfspace.Line(), ray);
if (RNIsNegative(d)) return -d;
else return 0.0;
}
RNLength R2Distance(const R2Line& line, const R2Span& span)
{
// Return distance from span to line
RNScalar d = R2SignedDistance(line, span);
if (RNIsPositive(d)) return d;
else if (RNIsNegative(d)) return -d;
else return 0.0;
}
RNLength R2Distance(const R2Point& point, const R2Arc& arc)
{
// Figure sector - positive ds are inside arc sector
RNLength d1 = R2SignedDistance(R2Line(arc.StartPoint(), arc.Center()), point);
RNLength d2 = R2SignedDistance(R2Line(arc.Center(), arc.StopPoint()), point);
if (d1 > 0.0) {
if (d2 > 0.0) {
// Point is in arc sector
RNLength d = R2Distance(arc.Center(), point) - arc.Radius();
return (d < 0) ? -d : d;
}
else {
// Point may be in arc sector
if (arc.SweepAngle() > RN_PI) {
// Point is in arc sector
RNLength d = R2Distance(arc.Center(), point) - arc.Radius();
return (d < 0) ? -d : d;
}
else {
// Point is closest to stop point
return R2Distance(arc.StopPoint(), point);
}
}
}
else {
if (d2 > 0.0) {
// Point may be in arc sector
if (arc.SweepAngle() > RN_PI) {
// Point is in arc sector
RNLength d = R2Distance(arc.Center(), point) - arc.Radius();
return (d < 0) ? -d : d;
}
else {
// Point is closest to start point
return R2Distance(arc.StartPoint(), point);
}
}
else {
// Point is outside arc sector
RNLength d = R2Distance(arc.Center(), point) - arc.Radius();
return (d < 0) ? -d : d;
}
}
}
RNLength R2SignedDistance(const R2Line& line, const R2Span& span)
{
// Return signed distance from line to span
RNLength d1 = R2SignedDistance(line, span.Start());
if (RNIsPositive(d1)) {
// Start point is above line
RNLength d2 = R2SignedDistance(line, span.End());
if (RNIsPositive(d2)) return ((d1 > d2) ? d2 : d1);
else return 0.0;
}
else if (RNIsNegative(d1)) {
// Start point is below line
RNLength d2 = R2SignedDistance(line, span.End());
if (RNIsNegative(d2)) return ((d1 > d2) ? d1 : d2);
else return 0.0;
}
else {
// Start point is on line
return 0.0;
}
}
RNLength R2SignedDistance(const R2Line& line, const R2Circle& circle)
{
RNLength d = R2SignedDistance(line, circle.Center());
if (d < 0.0) {
d += circle.Radius();
if (d > 0.0) return 0.0;
}
else if (d > 0.0) {
d -= circle.Radius();
if (d < 0.0) return 0.0;
}
return d;
}
