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 * Map a vector onto a plane.
42 * @param normal (in) normal vector for the plane
43 * @param v0 (in) a point on the plane
44 * @param vec (in) the vector to map onto the plane
45 * @param result (out) the result vector
47 inline void sgmap_vec_onto_cur_surface_plane( sgVec3 normal,
54 // calculate a vector "u1" representing the shortest distance from
55 // the plane specified by normal and v0 to a point specified by
56 // "vec". "u1" represents both the direction and magnitude of
57 // this desired distance.
59 // u1 = ( (normal <dot> vec) / (normal <dot> normal) ) * normal
63 ( sgScalarProductVec3(normal, vec) /
64 sgScalarProductVec3(normal, normal)
68 // printf(" vec = %.2f, %.2f, %.2f\n", vec[0], vec[1], vec[2]);
69 // printf(" v0 = %.2f, %.2f, %.2f\n", v0[0], v0[1], v0[2]);
70 // printf(" u1 = %.2f, %.2f, %.2f\n", u1[0], u1[1], u1[2]);
72 // calculate the vector "v" which is the vector "vec" mapped onto
73 // the plane specified by "normal" and "v0".
77 sgAddVec3(tmp, v0, vec);
78 sgSubVec3(v, tmp, u1);
79 // printf(" v = %.2f, %.2f, %.2f\n", v[0], v[1], v[2]);
81 // Calculate the vector "result" which is "v" - "v0" which is a
82 // directional vector pointing from v0 towards v
86 sgSubVec3(result, v, v0);
87 // printf(" result = %.2f, %.2f, %.2f\n",
88 // result[0], result[1], result[2]);
93 * Copy and negate a vector.
94 * @param dst (out) result vector
95 * @param src (in) input vector
97 inline void sgCopyNegateVec4( sgVec4 dst, sgVec4 src )
99 dst [ 0 ] = -src [ 0 ] ;
100 dst [ 1 ] = -src [ 1 ] ;
101 dst [ 2 ] = -src [ 2 ] ;
102 dst [ 3 ] = -src [ 3 ] ;
106 * Given a point p, and a line through p0 with direction vector d,
107 * find the closest point (p1) on the line (float version).
108 * @param p1 (out) closest point to p on the line
109 * @param p (in) original point
110 * @param p0 (in) point on the line
111 * @param d (in) vector defining line direction
113 void sgClosestPointToLine( sgVec3 p1, const sgVec3 p, const sgVec3 p0,
117 * Given a point p, and a line through p0 with direction vector d,
118 * find the closest point (p1) on the line (double version).
119 * @param p1 (out) closest point to p on the line
120 * @param p (in) original point
121 * @param p0 (in) point on the line
122 * @param d (in) vector defining line direction
124 void sgdClosestPointToLine( sgdVec3 p1, const sgdVec3 p, const sgdVec3 p0,
128 * Given a point p, and a line through p0 with direction vector d,
129 * find the shortest distance (squared) from the point to the line (float
131 * @param p (in) original point
132 * @param p0 (in) point on the line
133 * @param d (in) vector defining line direction
134 * @return shortest distance (squared) from p to line
136 double sgClosestPointToLineDistSquared( const sgVec3 p, const sgVec3 p0,
140 * Given a point p, and a line through p0 with direction vector d,
141 * find the shortest distance (squared) from the point to the line (double
143 * @param p (in) original point
144 * @param p0 (in) point on the line
145 * @param d (in) vector defining line direction
146 * @return shortest distance (squared) from p to line
148 double sgdClosestPointToLineDistSquared( const sgdVec3 p, const sgdVec3 p0,
154 * <li> sgMakeMatTrans4( sgMat4 sgTrans, sgVec3 trans )
155 * <li> sgPostMultMat4( sgMat4 src, sgTRANS );
157 * @param src starting sgMat4 matrix
158 * @param trans translation vector
160 void sgPostMultMat4ByTransMat4( sgMat4 src, const sgVec3 trans );
163 #endif // _VECTOR_HXX