ref: 7b8303673d908898d40ef36f03976c68c1bac489
dir: /code/splines/math_quaternion.cpp/
/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.
This file is part of Quake III Arena source code.
Quake III Arena source code 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.
Quake III Arena source code 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.
You should have received a copy of the GNU General Public License
along with Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
===========================================================================
*/
#include "math_quaternion.h"
#include "math_matrix.h"
void toQuat( idVec3_t &src, quat_t &dst ) {
dst.x = src.x;
dst.y = src.y;
dst.z = src.z;
dst.w = 0.0f;
}
void toQuat( angles_t &src, quat_t &dst ) {
mat3_t temp;
toMatrix( src, temp );
toQuat( temp, dst );
}
void toQuat( mat3_t &src, quat_t &dst ) {
float trace;
float s;
int i;
int j;
int k;
static int next[ 3 ] = { 1, 2, 0 };
trace = src[ 0 ][ 0 ] + src[ 1 ][ 1 ] + src[ 2 ][ 2 ];
if ( trace > 0.0f ) {
s = ( float )sqrt( trace + 1.0f );
dst.w = s * 0.5f;
s = 0.5f / s;
dst.x = ( src[ 2 ][ 1 ] - src[ 1 ][ 2 ] ) * s;
dst.y = ( src[ 0 ][ 2 ] - src[ 2 ][ 0 ] ) * s;
dst.z = ( src[ 1 ][ 0 ] - src[ 0 ][ 1 ] ) * s;
} else {
i = 0;
if ( src[ 1 ][ 1 ] > src[ 0 ][ 0 ] ) {
i = 1;
}
if ( src[ 2 ][ 2 ] > src[ i ][ i ] ) {
i = 2;
}
j = next[ i ];
k = next[ j ];
s = ( float )sqrt( ( src[ i ][ i ] - ( src[ j ][ j ] + src[ k ][ k ] ) ) + 1.0f );
dst[ i ] = s * 0.5f;
s = 0.5f / s;
dst.w = ( src[ k ][ j ] - src[ j ][ k ] ) * s;
dst[ j ] = ( src[ j ][ i ] + src[ i ][ j ] ) * s;
dst[ k ] = ( src[ k ][ i ] + src[ i ][ k ] ) * s;
}
}