libcruft-util/matrix.cpp
2014-07-15 19:50:49 +10:00

207 lines
6.2 KiB
C++

/*
* This file is part of libgim.
*
* libgim 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.
*
* libgim 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 libgim. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2011-2014 Danny Robson <danny@nerdcruft.net>
*/
#include "matrix.hpp"
#include "debug.hpp"
#include <cstring>
using namespace util;
//-----------------------------------------------------------------------------
template <typename T>
void
matrix<T>::scale (T x, T y, T z) {
CHECK_HARD (is_affine ());
values[0][0] *= x;
values[1][1] *= y;
values[2][2] *= z;
}
//-----------------------------------------------------------------------------
template <typename T>
void
matrix<T>::translate (T x, T y, T z) {
CHECK_HARD (is_affine ());
values[0][3] += x;
values[1][3] += y;
values[2][3] += z;
}
//-----------------------------------------------------------------------------
template <typename T>
matrix<T>
matrix<T>::inverse (void) const {
return matrix<T>(*this).invert ();
}
//-----------------------------------------------------------------------------
template <typename T>
matrix<T>&
matrix<T>::invert (void) {
CHECK_HARD (is_affine ());
// inv ([ M b ] == [ inv(M) -inv(M).b ]
// [ 0 1 ]) [ 0 1
// Invert the 3x3 M
T A = (values[1][1] * values[2][2] - values[1][2] * values[2][1]);
T B = (values[1][2] * values[2][0] - values[1][0] * values[2][2]);
T C = (values[1][0] * values[2][1] - values[1][1] * values[2][0]);
T D = (values[0][2] * values[2][1] - values[0][1] * values[2][2]);
T E = (values[0][0] * values[2][2] - values[0][2] * values[2][0]);
T F = (values[2][0] * values[0][1] - values[0][0] * values[2][1]);
T G = (values[0][1] * values[1][2] - values[0][2] * values[1][1]);
T H = (values[0][2] * values[1][0] - values[0][0] * values[1][2]);
T K = (values[0][0] * values[1][1] - values[0][1] * values[1][0]);
T det = values[0][0] * A + values[0][1] * B + values[0][2] * C;
CHECK_NEQ (det, 0.0);
values[0][0] = A / det;
values[0][1] = D / det;
values[0][2] = G / det;
values[1][0] = B / det;
values[1][1] = E / det;
values[1][2] = H / det;
values[2][0] = C / det;
values[2][1] = F / det;
values[2][2] = K / det;
// Multiply the b
T b0 = - values[0][0] * values[0][3] - values[0][1] * values[1][3] - values[0][2] * values[2][3];
T b1 = - values[1][0] * values[0][3] - values[1][1] * values[1][3] - values[1][2] * values[2][3];
T b2 = - values[2][0] * values[0][3] - values[2][1] * values[1][3] - values[2][2] * values[2][3];
values[0][3] = b0;
values[1][3] = b1;
values[2][3] = b2;
return *this;
}
//-----------------------------------------------------------------------------
template <typename T>
matrix<T>
matrix<T>::operator* (const matrix<T> &rhs) const {
matrix<T> m;
memset (m.values, 0, sizeof (m.values));
for (unsigned i = 0; i < 4; ++i)
for (unsigned j = 0; j < 4; ++j)
for (unsigned k = 0; k < 4; ++k)
m.values[i][j] += values[i][k] * rhs.values[k][j];
return m;
}
//-----------------------------------------------------------------------------
template <typename T>
util::point<3>
matrix<T>::to_local (const util::point<3> &p) const {
CHECK_SOFT (is_affine ());
return { p.x * values[0][0] +
p.y * values[0][1] +
p.z * values[0][2] + values[0][3],
p.x * values[1][0] +
p.y * values[1][1] +
p.z * values[1][2] + values[1][3],
p.x * values[2][0] +
p.y * values[2][1] +
p.z * values[2][2] + values[2][3] };
}
//-----------------------------------------------------------------------------
template <typename T>
util::point<3>
matrix<T>::to_global (const util::point<3> &p) const {
return inverse ().to_local (p);
}
//-----------------------------------------------------------------------------
template <typename T>
bool
matrix<T>::is_affine (void) const {
return exactly_equal (values[3][0], static_cast<T> (0)) &&
exactly_equal (values[3][1], static_cast<T> (0)) &&
exactly_equal (values[3][2], static_cast<T> (0)) &&
exactly_equal (values[3][3], static_cast<T> (1));
}
//-----------------------------------------------------------------------------
template <typename T>
const matrix<T>
matrix<T>::IDENTITY = { { { 1, 0, 0, 0 },
{ 0, 1, 0, 0 },
{ 0, 0, 1, 0 },
{ 0, 0, 0, 1 } } };
template <typename T>
const matrix<T>
matrix<T>::ZEROES = { { { 0, 0, 0, 0 },
{ 0, 0, 0, 0 },
{ 0, 0, 0, 0 },
{ 0, 0, 0, 0 } } };
//-----------------------------------------------------------------------------
namespace util {
template struct matrix<float>;
template struct matrix<double>;
}
//-----------------------------------------------------------------------------
template <typename T>
std::ostream&
operator<< (std::ostream &os, const matrix<T> &m) {
os << "{ {" << m.values[0][0] << ", "
<< m.values[0][1] << ", "
<< m.values[0][2] << ", "
<< m.values[0][3] << "}, "
<< "{" << m.values[1][0] << ", "
<< m.values[1][1] << ", "
<< m.values[1][2] << ", "
<< m.values[1][3] << "}, "
<< "{" << m.values[2][0] << ", "
<< m.values[2][1] << ", "
<< m.values[2][2] << ", "
<< m.values[2][3] << "}, "
<< "{" << m.values[3][0] << ", "
<< m.values[3][1] << ", "
<< m.values[3][2] << ", "
<< m.values[3][3] << "} }";
return os;
}