An abstract mathematical description of a plane. More...
Public Member Functions | |
LPlaned () | |
Creates a default plane. | |
LPlaned (Point3D const a, Point3D const b, Point3D const c) | |
Constructs a plane given three counter-clockwise points, as seen from the front of the plane (that is, viewed from the end of the normal vector, looking down). | |
LPlaned (VBase4D const copy) | |
LPlaned (Vec3D const normal, Point3D const point) | |
Constructs a plane given a surface normal vector and a point within the plane. | |
LPlaned (double a, double b, double c, double d) | |
Constructs a plane given the four terms of the plane equation. | |
double | distToPlane (Point3D const point) |
Returns the straight-line shortest distance from the point to the plane. | |
flip () | |
Convenience method that flips the plane in-place. | |
Vec3D | getNormal () |
Returns the surface normal of the plane. | |
Point3D | getPoint () |
Returns an arbitrary point in the plane. | |
Mat4D | getReflectionMat () |
This computes a transform matrix that reflects the universe to the other side of the plane, as in a mirror. | |
bool | intersectsLine (Point3D intersection_point, Point3D const p1, Point3D const p2) |
Returns true if the plane intersects the infinite line passing through points p1 and p2, false if the line is parallel. | |
bool | intersectsPlane (Point3D from, Vec3D delta, LPlaned const other) |
Returns true if the two planes intersect, false if they do not. | |
LPlaned | operator* (Mat3D const mat) |
Transforms the plane by the indicated matrix. | |
LPlaned | operator* (Mat4D const mat) |
Transforms the plane by the indicated matrix. | |
LPlaned | operator*= (Mat4D const mat) |
Transforms the plane by the indicated matrix. | |
LPlaned | operator- () |
Returns the same plane facing the opposite direction. | |
output (ostream out) | |
Point3D | project (Point3D const point) |
Returns the point within the plane nearest to the indicated point in space. | |
write (ostream out, int indent_level) | |
write (ostream out) | |
xform (Mat4D const mat) | |
Transforms the plane by the indicated matrix. |
An abstract mathematical description of a plane.
A plane is defined by the equation Ax + By + Cz + D = 0.
LPlaned | ( | ) |
Creates a default plane.
This plane happens to intersect the origin, perpendicular to the Z axis. It's not clear how useful a default plane is.
Constructs a plane given three counter-clockwise points, as seen from the front of the plane (that is, viewed from the end of the normal vector, looking down).
Constructs a plane given a surface normal vector and a point within the plane.
LPlaned | ( | double | a, |
double | b, | ||
double | c, | ||
double | d | ||
) |
Constructs a plane given the four terms of the plane equation.
double distToPlane | ( | Point3D const | point | ) |
Returns the straight-line shortest distance from the point to the plane.
The returned value is positive if the point is in front of the plane (on the side with the normal), or negative in the point is behind the plane (on the opposite side from the normal). It's zero if the point is exactly in the plane.
flip | ( | ) |
Convenience method that flips the plane in-place.
This is done by simply flipping the normal vector.
Returns an arbitrary point in the plane.
This can be used along with the normal returned by get_normal() to reconstruct the plane.
This computes a transform matrix that reflects the universe to the other side of the plane, as in a mirror.
bool intersectsLine | ( | Point3D | intersection_point, |
Point3D const | p1, | ||
Point3D const | p2 | ||
) |
Returns true if the plane intersects the infinite line passing through points p1 and p2, false if the line is parallel.
The points p1 and p2 are used only to define the Euclidean line; they have no other bearing on the intersection test. If true, sets intersection_point to the point of intersection.
bool intersectsPlane | ( | Point3D | from, |
Vec3D | delta, | ||
LPlaned const | other | ||
) |
Returns true if the two planes intersect, false if they do not.
If they do intersect, then from and delta are filled in with the parametric representation of the line of intersection: that is, from is a point on that line, and delta is a vector showing the direction of the line.
LPlaned operator- | ( | ) |
Returns the same plane facing the opposite direction.
Reimplemented from VBase4D.
Returns the point within the plane nearest to the indicated point in space.