//
// Written by Curtis Olson, started December 1997.
//
-// Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
+// Copyright (C) 1997 Curtis L. Olson - http://www.flightgear.org/~curt
//
-// This program is free software; you can redistribute it and/or
-// modify it under the terms of the GNU General Public License as
-// published by the Free Software Foundation; either version 2 of the
-// License, or (at your option) any later version.
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Library General Public
+// License as published by the Free Software Foundation; either
+// version 2 of the License, or (at your option) any later version.
//
-// This program is distributed in the hope that it will be useful, but
-// WITHOUT ANY WARRANTY; without even the implied warranty of
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-// General Public License for more details.
+// Library General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
-// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
#include "vector.hxx"
-#include "mat3.h"
-
-// Map a vector onto the plane specified by normal
-void map_vec_onto_cur_surface_plane(MAT3vec normal, MAT3vec v0, MAT3vec vec,
- MAT3vec result)
-{
- MAT3vec u1, v, tmp;
-
- // calculate a vector "u1" representing the shortest distance from
- // the plane specified by normal and v0 to a point specified by
- // "vec". "u1" represents both the direction and magnitude of
- // this desired distance.
-
- // u1 = ( (normal <dot> vec) / (normal <dot> normal) ) * normal
-
- MAT3_SCALE_VEC( u1,
- normal,
- ( MAT3_DOT_PRODUCT(normal, vec) /
- MAT3_DOT_PRODUCT(normal, normal)
- )
- );
-
- // printf(" vec = %.2f, %.2f, %.2f\n", vec[0], vec[1], vec[2]);
- // printf(" v0 = %.2f, %.2f, %.2f\n", v0[0], v0[1], v0[2]);
- // printf(" u1 = %.2f, %.2f, %.2f\n", u1[0], u1[1], u1[2]);
-
- // calculate the vector "v" which is the vector "vec" mapped onto
- // the plane specified by "normal" and "v0".
-
- // v = v0 + vec - u1
-
- MAT3_ADD_VEC(tmp, v0, vec);
- MAT3_SUB_VEC(v, tmp, u1);
- // printf(" v = %.2f, %.2f, %.2f\n", v[0], v[1], v[2]);
-
- // Calculate the vector "result" which is "v" - "v0" which is a
- // directional vector pointing from v0 towards v
-
- // result = v - v0
-
- MAT3_SUB_VEC(result, v, v0);
- // printf(" result = %.2f, %.2f, %.2f\n",
- // result[0], result[1], result[2]);
+// calculate the projection, p, of u along the direction of d.
+void sgProjection(sgVec3 p, const sgVec3 u, const sgVec3 d){
+ double denom = sgScalarProductVec3(d,d);
+ if (denom == 0.) sgCopyVec3(p, u);
+ else sgScaleVec3(p, d, sgScalarProductVec3(u,d) / denom);
}
+// Same thing, except using double precision
+void sgProjection(sgdVec3 p, const sgdVec3 u, const sgdVec3 d){
+ double denom = sgdScalarProductVec3(d,d);
+ if (denom == 0.) sgdCopyVec3(p, u);
+ else sgdScaleVec3(p, d, sgdScalarProductVec3(u,d) / denom);
+}
// Given a point p, and a line through p0 with direction vector d,
-// find the shortest distance from the point to the line
-double fgPointLine(MAT3vec p, MAT3vec p0, MAT3vec d) {
- MAT3vec u, u1, v;
- double ud, dd, tmp;
+// find the closest point (p1) on the line
+void sgClosestPointToLine( sgVec3 p1, const sgVec3 p, const sgVec3 p0,
+ const sgVec3 d ) {
+
+ sgVec3 u, u1;
// u = p - p0
- MAT3_SUB_VEC(u, p, p0);
+ sgSubVec3(u, p, p0);
// calculate the projection, u1, of u along d.
- // u1 = ( dot_prod(u, d) / dot_prod(d, d) ) * d;
- ud = MAT3_DOT_PRODUCT(u, d);
- dd = MAT3_DOT_PRODUCT(d, d);
- tmp = ud / dd;
-
- MAT3_SCALE_VEC(u1, d, tmp);;
+ sgProjection(u1, u, d);
- // v = u - u1 = vector from closest point on line, p1, to the
- // original point, p.
- MAT3_SUB_VEC(v, u, u1);
-
- return sqrt(MAT3_DOT_PRODUCT(v, v));
+ // calculate the point p1 along the line that is closest to p
+ // p0 = p1 + u1
+ sgAddVec3(p1, p0, u1);
}
// Given a point p, and a line through p0 with direction vector d,
-// find the shortest distance (squared) from the point to the line
-double fgPointLineSquared(MAT3vec p, MAT3vec p0, MAT3vec d) {
- MAT3vec u, u1, v;
- double ud, dd, tmp;
+// find the closest point (p1) on the line
+void sgdClosestPointToLine( sgdVec3 p1, const sgdVec3 p, const sgdVec3 p0,
+ const sgdVec3 d ) {
+
+ sgdVec3 u, u1;
// u = p - p0
- MAT3_SUB_VEC(u, p, p0);
+ sgdSubVec3(u, p, p0);
// calculate the projection, u1, of u along d.
- // u1 = ( dot_prod(u, d) / dot_prod(d, d) ) * d;
- ud = MAT3_DOT_PRODUCT(u, d);
- dd = MAT3_DOT_PRODUCT(d, d);
- tmp = ud / dd;
-
- MAT3_SCALE_VEC(u1, d, tmp);;
-
- // v = u - u1 = vector from closest point on line, p1, to the
- // original point, p.
- MAT3_SUB_VEC(v, u, u1);
+ sgProjection(u1, u, d);
- return ( MAT3_DOT_PRODUCT(v, v) );
+ // calculate the point p1 along the line that is closest to p
+ // p0 = p1 + u1
+ sgdAddVec3(p1, p0, u1);
}
// Given a point p, and a line through p0 with direction vector d,
// find the shortest distance (squared) from the point to the line
-double sgPointLineDistSquared( const sgVec3 p, const sgVec3 p0,
- const sgVec3 d ) {
+double sgClosestPointToLineDistSquared( const sgVec3 p, const sgVec3 p0,
+ const sgVec3 d ) {
sgVec3 u, u1, v;
- double ud, dd, tmp;
// u = p - p0
sgSubVec3(u, p, p0);
// calculate the projection, u1, of u along d.
- // u1 = ( dot_prod(u, d) / dot_prod(d, d) ) * d;
- ud = sgScalarProductVec3(u, d);
- dd = sgScalarProductVec3(d, d);
- tmp = ud / dd;
-
- sgScaleVec3(u1, d, tmp);;
+ sgProjection(u1, u, d);
// v = u - u1 = vector from closest point on line, p1, to the
// original point, p.
// Given a point p, and a line through p0 with direction vector d,
// find the shortest distance (squared) from the point to the line
-double sgdPointLineDistSquared( const sgdVec3 p, const sgdVec3 p0,
- const sgdVec3 d ) {
+double sgdClosestPointToLineDistSquared( const sgdVec3 p, const sgdVec3 p0,
+ const sgdVec3 d ) {
sgdVec3 u, u1, v;
- double ud, dd, tmp;
// u = p - p0
sgdSubVec3(u, p, p0);
// calculate the projection, u1, of u along d.
- // u1 = ( dot_prod(u, d) / dot_prod(d, d) ) * d;
- ud = sgdScalarProductVec3(u, d);
- dd = sgdScalarProductVec3(d, d);
- tmp = ud / dd;
-
- sgdScaleVec3(u1, d, tmp);;
+ sgProjection(u1, u, d);
// v = u - u1 = vector from closest point on line, p1, to the
// original point, p.
return ( sgdScalarProductVec3(v, v) );
}
+
+
+// This is a quicker form of
+// sgMakeMatTrans4( sgMat4 sgTrans, sgVec3 trans )
+// sgPostMultMat4( sgMat, sgTRANS );
+void sgPostMultMat4ByTransMat4( sgMat4 src, const sgVec3 trans )
+{
+ for( int i=0; i<4; i++) {
+ for( int j=0; j<3; j++ ) {
+ src[i][j] += (src[i][3] * trans[j]);
+ }
+ }
+}
+
+
projects / simgear.git / blobdiff