/****************************************************************************** * Bsc_Geom.c - Basic geometry interface. * ******************************************************************************* * (C) Gershon Elber, Technion, Israel Institute of Technology * ******************************************************************************* * Written by Gershon Elber, March 1990. * ******************************************************************************/ #include #include #include "program.h" #include "iritprsr.h" #include "allocate.h" #include "geomat3d.h" #include "bsc_geom.h" /***************************************************************************** * DESCRIPTION: M * Interface routine to compute the distance between two 3d points. M * * * PARAMETERS: M * P1, P2: Two points to compute the distance between. M * * * RETURN VALUE: M * double: Computed distance. M * M * SEE ALSO: M * CGDistPointPoint M * * * KEYWORDS: M * DistPointPoint, point point distance M *****************************************************************************/ double DistPointPoint(PointType P1, PointType P2) { return CGDistPointPoint(P1, P2); } /***************************************************************************** * DESCRIPTION: M * Interface routine to construct the plane from given 3 points. If two of M * the points are the same it returns FALSE, otherwise (successful) returns M * TRUE. M * * * PARAMETERS: M * Pt1, Pt2, Pt3: Three points to fit a plane through. M * * * RETURN VALUE: M * IPObjectStruct: The Plane, or NULL if invalid. M * M * SEE ALSO: M * CGPlaneFrom3Points M * * * KEYWORDS: M * PlaneFrom3Points, plane M *****************************************************************************/ IPObjectStruct *PlaneFrom3Points(PointType Pt1, PointType Pt2, PointType Pt3) { PlaneType Plane; if (CGPlaneFrom3Points(Plane, Pt1, Pt2, Pt3)) return GenPLANEObject(&Plane[0], &Plane[1], &Plane[2], &Plane[3]); else return NULL; } /***************************************************************************** * DESCRIPTION: M * Interface routine to compute the closest point on a given 3d line to a M * given 3d point. the line is prescribed using a point on it (Pl) and vector M * (Vl). M * * * PARAMETERS: M * Point: To find the closest to on the line. M * Pl, Vl: Position and direction that defines the line. M * * * RETURN VALUE: M * IPObjectStruct *: The closest point. M * M * SEE ALSO: M * CGPointFromPointLine M * * * KEYWORDS: M * PointFromPointLine, point line distance M *****************************************************************************/ IPObjectStruct *PointFromPointLine(PointType Point, PointType Pl, PointType Vl) { PointType ClosestPt; CGPointFromPointLine(Point, Pl, Vl, ClosestPt); return GenPTObject(&ClosestPt[0], &ClosestPt[1], &ClosestPt[2]); } /***************************************************************************** * DESCRIPTION: M * Interface routine to compute the disstance between a 3d point and a 3d M * line. M * The line is prescribed using a point on it (Pl) and vector (Vl). M * * * PARAMETERS: M * Point: To find the distance to on the line. M * Pl, Vl: Position and direction that defines the line. M * * * RETURN VALUE: M * double: The computed distance. M * M * SEE ALSO: M * CGDistPointLine M * * * KEYWORDS: M * DistPointLine, point line distance M *****************************************************************************/ double DistPointLine(PointType Point, PointType Pl, PointType Vl) { return CGDistPointLine(Point, Pl, Vl); } /***************************************************************************** * DESCRIPTION: M * Interface routine to compute the distance between a Point and a Plane. M * The Plane is prescribed using its four coefficients : Ax + By + Cz + D = 0 M * given as four elements vector. M * * * PARAMETERS: M * Point: To find the distance to on the plane. M * Plane: To find the distance to on the point. M * * * RETURN VALUE: M * double: The computed distance. M * M * SEE ALSO: M * CGDistPointPlane M * * * KEYWORDS: M * DistPointPlane, point plane distance M *****************************************************************************/ double DistPointPlane(PointType Point, PlaneType Plane) { return CGDistPointPlane(Point, Plane); } /***************************************************************************** * DESCRIPTION: M * Interface routine to find the intersection point of a line and a plane M * (if any). M * The Plane is prescribed using four coefficients : Ax + By + Cz + D = 0 M * given as four elements vector. The line is define via a point on it Pl and M * a direction vector Vl. Returns TRUE only if such point exists. M * * * PARAMETERS: M * Pl, Vl: Position and direction that defines the line. M * Plane: To find the intersection with the line. M * InterPoint: Where the intersection occured. M * t: Parameter along the line of the intersection location M * (as Pl + Vl * t). M * * * RETURN VALUE: M * IPObjectStruct *: The intersection point, or NULL if none. M * M * SEE ALSO: M * CGPointFromLinePlane M * * * KEYWORDS: M * PointFromLinePlane, line plane intersection M *****************************************************************************/ IPObjectStruct *PointFromLinePlane(PointType Pl, PointType Vl, PlaneType Plane) { RealType t; PointType InterPoint; if (CGPointFromLinePlane(Pl, Vl, Plane, InterPoint, &t)) return GenPTObject(&InterPoint[0], &InterPoint[1], &InterPoint[2]); else return NULL; } /***************************************************************************** * DESCRIPTION: M * Interface routine to find the two points Pti on the lines (Pli, Vli) , M * i = 1, 2 with the minimal Euclidian distance between them. In other M * words, the distance between Pt1 and Pt2 is defined as distance between the M * two lines. M * The two points are calculated using the fact that if V = (Vl1 cross Vl2) M * then these two points are the intersection point between the following: M * Point 1 - a plane (defined by V and line1) and the line line2. M * Point 2 - a plane (defined by V and line2) and the line line1. M * This function returns TRUE iff the two lines are not parallel! M * M * PARAMETERS: M * Pl1, Vl1: Position and direction defining the first line. M * Pl2, Vl2: Position and direction defining the second line. M * Pt1: Point on Pt1 that is closest to line 2. M * t1: Parameter value of Pt1 as (Pl1 + Vl1 * t1). M * Pt2: Point on Pt2 that is closest to line 1. M * t2: Parameter value of Pt2 as (Pl2 + Vl2 * t2). M * * * RETURN VALUE: M * IPObjectStruct *: List of two closest points, NULL if none. M * M * SEE ALSO: M * CG2PointsFromLineLine M * * * KEYWORDS: M * 2PointsFromLineLine, line line distance M *****************************************************************************/ IPObjectStruct *TwoPointsFromLineLine(PointType Pl1, PointType Vl1, PointType Pl2, PointType Vl2) { PointType Pt1, Pt2; RealType t1, t2; if (CG2PointsFromLineLine(Pl1, Vl1, Pl2, Vl2, Pt1, &t1, Pt2, &t2)) { IPObjectStruct *PObj = IPAllocObject("", IP_OBJ_LIST_OBJ, NULL); ListObjectInsert(PObj, 0, GenPTObject(&Pt1[0], &Pt1[1], &Pt1[2])); ListObjectInsert(PObj, 1, GenPTObject(&Pt2[0], &Pt2[1], &Pt2[2])); ListObjectInsert(PObj, 2, NULL); return PObj; } else return NULL; } /***************************************************************************** * DESCRIPTION: M * Interface routine to find the distance between two lines (Pli, Vli) , M * i = 1, 2. M * * * PARAMETERS: M * Pl1, Vl1: Position and direction defining the first line. M * Pl2, Vl2: Position and direction defining the second line. M * * * RETURN VALUE: M * double: Distance between the two lines. M * M * SEE ALSO: M * CGDistLineLine M * * * KEYWORDS: M * DistLineLine, line line distance M *****************************************************************************/ double DistLineLine(PointType Pl1, PointType Vl1, PointType Pl2, PointType Vl2) { return CGDistLineLine(Pl1, Vl1, Pl2, Vl2); } /***************************************************************************** * DESCRIPTION: M * Interface to compute the Barycentric coordinates of given point Pt with M * respect to given Trainagle Pt1 Pt2 Pt3. All points are assumed to be M * coplanar. M * * * PARAMETERS: M * Pt1, Pt2, Pt3: Three points forming a triangular in general position. M * Pt: A point for which the barycentric coordinates are to be M * computed. M * * * RETURN VALUE: M * IPObjectStruct *: A vector holding the three Barycentric M * coefficients, or NULL if point Pt is outside the triangle M * Pt1 Pt2 Pt3. M * M * SEE ALSO: M * CGBaryCentric3Pts M * * * KEYWORDS: M * BaryCentric3Pts M *****************************************************************************/ IPObjectStruct *BaryCentric3Pts(PointType Pt1, PointType Pt2, PointType Pt3, PointType Pt) { RealType *V; if ((V = CGBaryCentric3Pts(Pt1, Pt2, Pt3, Pt)) != NULL) return GenPTObject(&V[0], &V[1], &V[2]); else return NULL; }