typedef struct { vec3 n; // normal float d; // distance along normal from the origin } Plane; typedef struct { vec3 n; // normal vec3 p; // an arbitrary point on the plane } PlaneP;

Not all distance and intersection functions have systematic names yet. In general, functions are named in the pattern [operation][lesser]N[greater]N(l, g, [args], out*) where operation is something like dist or intersect, lesser is the argument with fewer dimensions, greater is the argument with more dimensions, and N is the number of dimensions if otherwise unclear (lines and triangles can exist in 2 or 3 dimensions, for example, but spheres and circles imply their dimensionality). Functions with "T" in the name return a normalized value along with whatever other results.

Primitives

Line: An infinite line, unless otherwise specified, with no implied direction.
Ray: A line with a start location that extends inifinitely in some specified direction.
Rect: An axis-aligned rectangle defined by two opposing corners.
Quad: An arbitrary quadrilateral in 2 or 3 dimensions defined by a loop of consecutive corners. May or may not need to be planar or rectangular (right angles) depending on the function.
Circle: A circle defined by a center and a radius in 2 dimensions.
Plane: An infinite plane in 3 dimensions defined by a normal vector and a distance from the origin.
PlaneP: An infinite plane in 3 dimensions defined by a normal vector and a point on the plane.
Sphere: A sphere in 3 dimensions defined by a center and a radius.
Capsule: A pill-shaped 3D object defined by the center points of the two connected end spheres and a radius.

Operation Stubs

dist: Shortest distance between the two objects.
intersect: Determines if the two objects intersect.
findIntersect: Finds the point (or line) of intersection between two objects. Unless otherwise specified, it's the closest point of intersection if there are multiple.
proj: Projects the first object onto the second, whatever that means for the objects involved.

Functions

int intersectPlaneRay3p(Plane* pl, Ray3* ray, vec3* ipoint, float* idist)

Negative values of idist are "behind" ray->o. Returns C3DLAS_INTERSECT, C3DLAS_PARALLEL or C3DLAS_DISJOINT.

int findIntersectLinePlane(Line3 l, Plane* pl, Vector3* out)

Returns C3DLAS_INTERSECT, C3DLAS_COPLANAR or C3DLAS_DISJOINT.

int findIntersectFastLinePlane(Line3 l, Plane* pl, Vector3* out)

Assumes that the line and plan intersect; does not check for coplanarity. Returns C3DLAS_INTERSECT, C3DLAS_COPLANAR or C3DLAS_DISJOINT.

void vProjectOntoPlane3p(Vector3* v, Plane* p, Vector3* out); void vProjectOntoPlaneNormalized3p(Vector3* v, Plane* p, Vector3* out); void planeFromPointNormal(Vector3* p, Vector3* norm, Plane* out); void planeFromTriangle3p(Vector3* v1, Vector3* v2, Vector3* v3, Plane* out); // calculates a plane form a triangle void planeCopy3p(Plane* in, Plane* out); // copy a plane void planeInverse3p(Plane* in, Plane* out); // flips the plane's direction int planeClassifyPoint3p(Plane* p, Vector3* pt); // classifies a point by which side of the plane it's on, default espilon int planeClassifyPointEps3p(Plane* p, Vector3* pt, float epsilon); // classifies a point by which side of the plane it's on, custom espilon // closest distance from an arbitrary point to the plane float planePointDist3p(Plane* pl, Vector3* p); // signed closest distance from an arbitrary point to the plane float planePointDistSigned3p(Plane* pl, Vector3* p); // C3DLAS_INTERSECT, _PARALLEL or _DISJOINT // negative values of idist are "behind" ray->o int intersectPlaneRay3p(Plane* pl, Ray3* ray, Vector3* ipoint, float* idist); // C3DLAS_COPLANAR, _PARALLEL, _INTERSECT, or _DISJOINT // aboveCnt and belowCnt are always set. int linePlaneClip3p( Vector3* la, Vector3* lb, Plane* pl, Vector3* aboveOut, Vector3* belowOut, int* aboveCnt, int* belowCnt );