3 * Additional vector routines.
6 // Written by Curtis Olson, started December 1997.
8 // Copyright (C) 1997 Curtis L. Olson - http://www.flightgear.org/~curt
10 // This library is free software; you can redistribute it and/or
11 // modify it under the terms of the GNU Library General Public
12 // License as published by the Free Software Foundation; either
13 // version 2 of the License, or (at your option) any later version.
15 // This library is distributed in the hope that it will be useful,
16 // but WITHOUT ANY WARRANTY; without even the implied warranty of
17 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 // Library General Public License for more details.
20 // You should have received a copy of the GNU General Public License
21 // along with this program; if not, write to the Free Software
22 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
32 # error This library requires C++
35 #include <simgear/compiler.h>
41 * calculate the projection, p, of u along the direction of d.
42 * @param p (out) the projection
43 * @param u (in) the vector to be projected
44 * @param d (in) the direction onto which we project
46 void sgProjection(sgVec3 p, const sgVec3 u, const sgVec3 d);
47 void sgProjection(sgdVec3 p, const sgdVec3 u, const sgdVec3 d);
51 * Map i.e. project a vector onto a plane.
52 * @param normal (in) normal vector for the plane
53 * @param v0 (in) a point on the plane
54 * @param vec (in) the vector to map onto the plane
55 * @param result (out) the result vector
57 inline void sgmap_vec_onto_cur_surface_plane( sgVec3 normal,
64 // calculate a vector "u1" representing the shortest distance from
65 // the plane specified by normal and v0 to a point specified by
66 // "vec". "u1" represents both the direction and magnitude of
67 // this desired distance.
69 // u1 = ( (normal <dot> vec) / (normal <dot> normal) ) * normal
73 ( sgScalarProductVec3(normal, vec) /
74 sgScalarProductVec3(normal, normal)
78 // printf(" vec = %.2f, %.2f, %.2f\n", vec[0], vec[1], vec[2]);
79 // printf(" v0 = %.2f, %.2f, %.2f\n", v0[0], v0[1], v0[2]);
80 // printf(" u1 = %.2f, %.2f, %.2f\n", u1[0], u1[1], u1[2]);
82 // calculate the vector "v" which is the vector "vec" mapped onto
83 // the plane specified by "normal" and "v0".
87 sgAddVec3(tmp, v0, vec);
88 sgSubVec3(v, tmp, u1);
89 // printf(" v = %.2f, %.2f, %.2f\n", v[0], v[1], v[2]);
91 // Calculate the vector "result" which is "v" - "v0" which is a
92 // directional vector pointing from v0 towards v
96 sgSubVec3(result, v, v0);
97 // printf(" result = %.2f, %.2f, %.2f\n",
98 // result[0], result[1], result[2]);
103 * Copy and negate a vector.
104 * @param dst (out) result vector
105 * @param src (in) input vector
107 inline void sgCopyNegateVec4( sgVec4 dst, sgVec4 src )
109 dst [ 0 ] = -src [ 0 ] ;
110 dst [ 1 ] = -src [ 1 ] ;
111 dst [ 2 ] = -src [ 2 ] ;
112 dst [ 3 ] = -src [ 3 ] ;
116 * Given a point p, and a line through p0 with direction vector d,
117 * find the closest point (p1) on the line (float version).
118 * @param p1 (out) closest point to p on the line
119 * @param p (in) original point
120 * @param p0 (in) point on the line
121 * @param d (in) vector defining line direction
123 void sgClosestPointToLine( sgVec3 p1, const sgVec3 p, const sgVec3 p0,
127 * Given a point p, and a line through p0 with direction vector d,
128 * find the closest point (p1) on the line (double version).
129 * @param p1 (out) closest point to p on the line
130 * @param p (in) original point
131 * @param p0 (in) point on the line
132 * @param d (in) vector defining line direction
134 void sgdClosestPointToLine( sgdVec3 p1, const sgdVec3 p, const sgdVec3 p0,
138 * Given a point p, and a line through p0 with direction vector d,
139 * find the shortest distance (squared) from the point to the line (float
141 * @param p (in) original point
142 * @param p0 (in) point on the line
143 * @param d (in) vector defining line direction
144 * @return shortest distance (squared) from p to line
146 double sgClosestPointToLineDistSquared( const sgVec3 p, const sgVec3 p0,
150 * Given a point p, and a line through p0 with direction vector d,
151 * find the shortest distance (squared) from the point to the line (double
153 * @param p (in) original point
154 * @param p0 (in) point on the line
155 * @param d (in) vector defining line direction
156 * @return shortest distance (squared) from p to line
158 double sgdClosestPointToLineDistSquared( const sgdVec3 p, const sgdVec3 p0,
164 * <li> sgMakeMatTrans4( sgMat4 sgTrans, sgVec3 trans )
165 * <li> sgPostMultMat4( sgMat4 src, sgTRANS );
167 * @param src starting sgMat4 matrix
168 * @param trans translation vector
170 void sgPostMultMat4ByTransMat4( sgMat4 src, const sgVec3 trans );
173 #endif // _VECTOR_HXX