@Override // from IBox
public boolean intersection(IRay3 ray, Vector3 result) {
IVector3 origin = ray.origin();
if (contains(origin)) {
result.set(origin);
return true;
}
IVector3 dir = ray.direction();
double t = Float.MAX_VALUE;
if (Math.abs(dir.x()) > MathUtil.EPSILON) {
t = Math.min(t, intersectionX(ray, _minExtent.x));
t = Math.min(t, intersectionX(ray, _maxExtent.x));
}
if (Math.abs(dir.y()) > MathUtil.EPSILON) {
t = Math.min(t, intersectionY(ray, _minExtent.y));
t = Math.min(t, intersectionY(ray, _maxExtent.y));
}
if (Math.abs(dir.z()) > MathUtil.EPSILON) {
t = Math.min(t, intersectionZ(ray, _minExtent.z));
t = Math.min(t, intersectionZ(ray, _maxExtent.z));
}
if (t == Float.MAX_VALUE) {
return false;
}
origin.addScaled(dir, t, result);
return true;
}
/**
* Helper method for {@link #intersects(Ray3)}. Determines whether the ray intersects the box at
* the plane where z equals the value specified.
*/
protected boolean intersectsZ(IRay3 ray, double z) {
IVector3 origin = ray.origin(), dir = ray.direction();
double t = (z - origin.z()) / dir.z();
if (t < 0f) {
return false;
}
double ix = origin.x() + t * dir.x(), iy = origin.y() + t * dir.y();
return ix >= _minExtent.x && ix <= _maxExtent.x && iy >= _minExtent.y && iy <= _maxExtent.y;
}
/**
* Helper method for {@link #intersects(Ray3)}. Determines whether the ray intersects the box at
* the plane where y equals the value specified.
*/
protected boolean intersectsY(IRay3 ray, double y) {
IVector3 origin = ray.origin(), dir = ray.direction();
double t = (y - origin.y()) / dir.y();
if (t < 0f) {
return false;
}
double ix = origin.x() + t * dir.x(), iz = origin.z() + t * dir.z();
return ix >= _minExtent.x && ix <= _maxExtent.x && iz >= _minExtent.z && iz <= _maxExtent.z;
}
/**
* Helper method for {@link #intersects(Ray3)}. Determines whether the ray intersects the box at
* the plane where x equals the value specified.
*/
protected boolean intersectsX(IRay3 ray, double x) {
IVector3 origin = ray.origin(), dir = ray.direction();
double t = (x - origin.x()) / dir.x();
if (t < 0f) {
return false;
}
double iy = origin.y() + t * dir.y(), iz = origin.z() + t * dir.z();
return iy >= _minExtent.y && iy <= _maxExtent.y && iz >= _minExtent.z && iz <= _maxExtent.z;
}
/**
* Helper method for {@link #intersection}. Finds the <code>t</code> value where the ray
* intersects the box at the plane where z equals the value specified, or returns {@link
* Float#MAX_VALUE} if there is no such intersection.
*/
protected double intersectionZ(IRay3 ray, double z) {
IVector3 origin = ray.origin(), dir = ray.direction();
double t = (z - origin.z()) / dir.z();
if (t < 0f) {
return Float.MAX_VALUE;
}
double ix = origin.x() + t * dir.x(), iy = origin.y() + t * dir.y();
return (ix >= _minExtent.x && ix <= _maxExtent.x && iy >= _minExtent.y && iy <= _maxExtent.y)
? t
: Float.MAX_VALUE;
}
/**
* Helper method for {@link #intersection}. Finds the <code>t</code> value where the ray
* intersects the box at the plane where y equals the value specified, or returns {@link
* Float#MAX_VALUE} if there is no such intersection.
*/
protected double intersectionY(IRay3 ray, double y) {
IVector3 origin = ray.origin(), dir = ray.direction();
double t = (y - origin.y()) / dir.y();
if (t < 0f) {
return Float.MAX_VALUE;
}
double ix = origin.x() + t * dir.x(), iz = origin.z() + t * dir.z();
return (ix >= _minExtent.x && ix <= _maxExtent.x && iz >= _minExtent.z && iz <= _maxExtent.z)
? t
: Float.MAX_VALUE;
}
@Override // from IBox
public boolean intersects(IRay3 ray) {
IVector3 dir = ray.direction();
return Math.abs(dir.x()) > MathUtil.EPSILON
&& (intersectsX(ray, _minExtent.x) || intersectsX(ray, _maxExtent.x))
|| Math.abs(dir.y()) > MathUtil.EPSILON
&& (intersectsY(ray, _minExtent.y) || intersectsY(ray, _maxExtent.y))
|| Math.abs(dir.z()) > MathUtil.EPSILON
&& (intersectsZ(ray, _minExtent.z) || intersectsZ(ray, _maxExtent.z));
}
