125 lines
3.0 KiB
C++
125 lines
3.0 KiB
C++
/*
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* This file is part of libgim.
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*
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* libgim is free software: you can redistribute it and/or modify it under the
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* terms of the GNU General Public License as published by the Free Software
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* Foundation, either version 3 of the License, or (at your option) any later
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* version.
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*
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* libgim is distributed in the hope that it will be useful, but WITHOUT ANY
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* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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* details.
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*
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* You should have received a copy of the GNU General Public License
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* along with libgim. If not, see <http://www.gnu.org/licenses/>.
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*
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* Copyright 2015 Danny Robson <danny@nerdcruft.net>
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*/
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#include "bezier.hpp"
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#include "debug.hpp"
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#include <algorithm>
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#include <iterator>
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//-----------------------------------------------------------------------------
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template <size_t S>
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util::bezier<S>::bezier (const util::point2f (&_points)[S+1])
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{
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std::copy (_points, _points + S + 1, m_points);
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}
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//-----------------------------------------------------------------------------
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namespace util {
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template <>
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point2f
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bezier<1>::eval (float t) const
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{
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CHECK_GE (t, 0);
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CHECK_LE (t, 1);
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auto v0 = (1 - t) * m_points[0];
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auto v1 = t * m_points[1];
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return {
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v0.x + v1.x,
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v0.y + v1.y
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};
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}
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}
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//-----------------------------------------------------------------------------
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namespace util {
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template <>
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point2f
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bezier<2>::eval (float t) const
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{
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CHECK_GE (t, 0);
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CHECK_LE (t, 1);
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auto v0 = pow2 (1 - t) * m_points[0];
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auto v1 = 2 * (1 - t) * t * m_points[1];
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auto v2 = pow2 (t) * m_points[2];
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return {
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v0.x + v1.x + v2.x,
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v0.y + v1.y + v2.y
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};
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}
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}
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//-----------------------------------------------------------------------------
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namespace util {
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template <>
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point2f
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bezier<3>::eval (float t) const
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{
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CHECK_GE (t, 0);
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CHECK_LE (t, 1);
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auto v0 = pow (1 - t, 3) * m_points[0];
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auto v1 = 3 * pow2 (1 - t) * t * m_points[1];
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auto v2 = 3 * pow2 (1 - t) * t * m_points[2];
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auto v3 = pow (t, 3) * m_points[3];
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return {
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v0.x + v1.x + v2.x + v3.x,
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v0.y + v1.y + v2.y + v3.y
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};
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}
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}
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//-----------------------------------------------------------------------------
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template <size_t S>
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util::point2f&
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util::bezier<S>::operator[] (size_t idx)
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{
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CHECK_LE (idx, S);
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return m_points[idx];
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}
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//-----------------------------------------------------------------------------
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template <size_t S>
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const util::point2f&
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util::bezier<S>::operator[] (size_t idx) const
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{
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CHECK_LE (idx, S);
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return m_points[idx];
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}
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//-----------------------------------------------------------------------------
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template class util::bezier<2>;
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template class util::bezier<3>;
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template class util::bezier<4>;
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