scummvm/math/matrix3.cpp
2012-12-19 23:15:43 +01:00

77 lines
2.5 KiB
C++

/* ResidualVM - A 3D game interpreter
*
* ResidualVM 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 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 program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "math/matrix3.h"
namespace Math {
Matrix<3, 3>::Matrix() :
MatrixType<3, 3>(), Rotation3D<Matrix<3, 3> >() {
}
Matrix<3, 3>::Matrix(const MatrixBase<3, 3> &m) :
MatrixType<3, 3>(m), Rotation3D<Matrix<3, 3> >() {
}
void swap (float &a, float &b) {
float c=a; a=b; b=c;
}
void Matrix<3, 3>::transpose() {
swap(operator()(0,1), operator()(1,0));
swap(operator()(0,2), operator()(2,0));
swap(operator()(1,2), operator()(2,1));
}
/**
* Generates a lookat matrix. For reference, see
* http://clb.demon.fi/MathGeoLib/docs/float3x3_LookAt.php
*/
void Matrix<3, 3>::buildFromTargetDir(const Math::Vector3d &modelForward, const Math::Vector3d &targetDirection,
const Math::Vector3d &modelUp, const Math::Vector3d &worldUp)
{
Math::Vector3d modelRight = Math::Vector3d::crossProduct(modelUp, modelForward);
modelRight.normalize();
Math::Vector3d worldRight = Math::Vector3d::crossProduct(worldUp, targetDirection);
worldRight.normalize();
Math::Vector3d perpWorldUp = Math::Vector3d::crossProduct(targetDirection, worldRight);
perpWorldUp.normalize();
Math::Matrix3 m1;
m1.getRow(0) << worldRight.x() << worldRight.y() << worldRight.z();
m1.getRow(1) << perpWorldUp.x() << perpWorldUp.y() << perpWorldUp.z();
m1.getRow(2) << targetDirection.x() << targetDirection.y() << targetDirection.z();
m1.transpose();
Math::Matrix3 m2;
m2.getRow(0) << modelRight.x() << modelRight.y() << modelRight.z();
m2.getRow(1) << modelUp.x() << modelUp.y() << modelUp.z();
m2.getRow(2) << modelForward.x() << modelForward.y() << modelForward.z();
this->operator=(m1 * m2);
}
} // end of namespace Math