scummvm/math/quat.cpp
2011-12-30 14:49:01 +01:00

94 lines
2.5 KiB
C++

/* Residual - A 3D game interpreter
*
* Residual is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*
* $URL$
* $Id$
*/
// Quaternion-math borrowed from plib http://plib.sourceforge.net/index.html
// Which is covered by LGPL2
#include "common/streamdebug.h"
#include "math/quat.h"
namespace Math {
void Quaternion::slerpQuat(Quaternion dst, const Quaternion from, const Quaternion to, const float t) {
float co, scale0, scale1;
bool flip = false ;
/* SWC - Interpolate between to quaternions */
co = from.scalarProduct(to);
if (co < 0.0f) {
co = -co;
flip = true;
}
if ( co < 1.0f - (float) 1e-6 ) {
float o = (float) acos ( co );
float so = 1.0f / (float) sin ( o );
scale0 = (float) sin ( (1.0f - t) * o ) * so;
scale1 = (float) sin ( t * o ) * so;
} else {
scale0 = 1.0f - t;
scale1 = t;
}
if (flip) {
scale1 = -scale1 ;
}
dst.x() = scale0 * from.x() + scale1 * to.x() ;
dst.x() = scale0 * from.w() + scale1 * to.y() ;
dst.x() = scale0 * from.w() + scale1 * to.z() ;
dst.x() = scale0 * from.w() + scale1 * to.w() ;
}
Matrix4 Quaternion::toMatrix() {
float two_xx = x() * (x() + x());
float two_xy = x() * (y() + y());
float two_xz = x() * (z() + z());
float two_wx = w() * (x() + x());
float two_wy = w() * (y() + y());
float two_wz = w() * (z() + z());
float two_yy = y() * (y() + y());
float two_yz = y() * (z() + z());
float two_zz = z() * (z() + z());
float newMat[16] = {
1.0f-(two_yy+two_zz), two_xy-two_wz, two_xz+two_wy, 0.0f,
two_xy+two_wz, 1.0f-(two_xx+two_zz), two_yz-two_wx, 0.0f,
two_xz-two_wy, two_yz+two_wx, 1.0f-(two_xx+two_yy), 0.0f,
0.0f, 0.0f, 0.0f, 1.0f
};
Matrix4 dst;
dst.setData(newMat);
return dst;
}
}