scummvm/math/matrix4.cpp

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

#include "math/matrix4.h"
#include "math/vector4d.h"
#include "math/squarematrix.h"

namespace Math {

Matrix<4, 4>::Matrix() :
	MatrixType<4, 4>(), Rotation3D<Matrix4>() {
}

Matrix<4, 4>::Matrix(const MatrixBase<4, 4> &m) :
	MatrixType<4, 4>(m), Rotation3D<Matrix4>() {
}

void Matrix<4, 4>::transform(Vector3d *v, bool trans) const {
	Vector4d m;
	m(0, 0) = v->x();
	m(1, 0) = v->y();
	m(2, 0) = v->z();
	m(3, 0) = (trans ? 1.f : 0.f);

	m = *this * m;

	v->set(m(0, 0), m(1, 0), m(2, 0));
}

Vector3d Matrix<4, 4>::getPosition() const {
	return Vector3d(getValue(0, 3), getValue(1, 3), getValue(2, 3));
}

void Matrix<4, 4>::setPosition(const Vector3d &v) {
	setValue(0, 3, v.x());
	setValue(1, 3, v.y());
	setValue(2, 3, v.z());
}

Matrix3 Matrix<4, 4>::getRotation() const{
	Matrix3 m2;

	m2.setValue(0, 0, getValue(0, 0));
	m2.setValue(0, 1, getValue(0, 1));
	m2.setValue(0, 2, getValue(0, 2));
	m2.setValue(1, 0, getValue(1, 0));
	m2.setValue(1, 1, getValue(1, 1));
	m2.setValue(1, 2, getValue(1, 2));
	m2.setValue(2, 0, getValue(2, 0));
	m2.setValue(2, 1, getValue(2, 1));
	m2.setValue(2, 2, getValue(2, 2));

	return m2;
}

void Matrix<4, 4>::setRotation(const Matrix3 &m) {
	setValue(0, 0, m.getValue(0, 0));
	setValue(0, 1, m.getValue(0, 1));
	setValue(0, 2, m.getValue(0, 2));
	setValue(1, 0, m.getValue(1, 0));
	setValue(1, 1, m.getValue(1, 1));
	setValue(1, 2, m.getValue(1, 2));
	setValue(2, 0, m.getValue(2, 0));
	setValue(2, 1, m.getValue(2, 1));
	setValue(2, 2, m.getValue(2, 2));
}

void Matrix<4, 4>::translate(const Vector3d &vec) {
	Vector3d v(vec);
	transform(&v, false);

	operator()(0, 3) += v.x();
	operator()(1, 3) += v.y();
	operator()(2, 3) += v.z();
}

/**
 * Generates a lookat matrix. For reference, see
 * http://clb.confined.space/MathGeoLib/nightly/docs/float3x3_LookAt.php
 */
void Matrix<4, 4>::buildFromTargetDir(const Math::Vector3d &modelForward, const Math::Vector3d &targetDirection,
                                      const Math::Vector3d &modelUp, const Math::Vector3d &worldUp) {
	Matrix3 rotation;
	rotation.buildFromTargetDir(modelForward, targetDirection, modelUp, worldUp);
	this->setRotation(rotation);
}

void Matrix<4, 4>::invertAffineOrthonormal() {
	Matrix3 rotation(getRotation());
	rotation.transpose();

	Vector3d position(getPosition().getNegative());

	rotation.transformVector(&position);
	setRotation(rotation);
	setPosition(position);
}

void swap(float &a, float &b);

void Matrix<4, 4>::transpose() {
	swap(operator ()(0,1), operator ()(1,0));
	swap(operator ()(0,2), operator ()(2,0));
	swap(operator ()(0,3), operator ()(3,0));

	swap(operator ()(1,2), operator ()(2,1));
	swap(operator ()(1,3), operator ()(3,1));
	swap(operator ()(2,3), operator ()(3,2));
}

} // end of namespace Math