Converted to the LGPL licencing terms.

[simgear.git] / simgear / math / vector.cxx

diff --git a/simgear/math/vector.cxx b/simgear/math/vector.cxx
index 75a0cb7af08ad7581e583491bb1d075bdaa1adcc..637ea4bc0803e8507e631828a6a69811bb34e66a 100644 (file)
--- a/simgear/math/vector.cxx
+++ b/simgear/math/vector.cxx
@@ -4,19 +4,20 @@
 //
 // Copyright (C) 1997  Curtis L. Olson  - curt@infoplane.com
 //
-// 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.
+// You should have received a copy of the GNU Library General Public
+// License along with this library; if not, write to the
+// Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+// Boston, MA  02111-1307, USA.
 //
 // $Id$
 
@@ -35,18 +36,13 @@ double sgPointLineDistSquared( 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);;
+    sgScaleVec3( u1, d, sgScalarProductVec3(u,d) / sgScalarProductVec3(d,d) );
 
     // v = u - u1 = vector from closest point on line, p1, to the
     // original point, p.
@@ -81,3 +77,18 @@ double sgdPointLineDistSquared( const sgdVec3 p, const sgdVec3 p0,
 
     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]);
+       }
+    }
+}
+
+