99 lines
4.1 KiB
C++
99 lines
4.1 KiB
C++
/**
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This file is a part of our_dick
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Copyright (C) 2020 rexy712
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU Affero General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Affero General Public License for more details.
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You should have received a copy of the GNU Affero General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef OUR_DICK_MATH_PROJECTION_TPP
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#define OUR_DICK_MATH_PROJECTION_TPP
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#include "mat.hpp"
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#include "vec.hpp"
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#include <cmath> //sin, cos, tan
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namespace math{
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template<typename T>
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matrix<T,4,4> fov_projection(T fov, T asp, T near, T far){
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T r = near * std::tan(fov / T{2.0});
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return matrix<T,4,4>((near / r) / asp, T{0}, T{0}, T{0},
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T{0}, (near / r), T{0}, T{0},
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T{0}, T{0}, (far + near) / (near - far), -T{1},
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T{0}, T{0}, (T{2} * near * far) / (near - far), T{0});
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}
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template<typename T>
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matrix<T,4,4> fov_asymetric_projection(T fovl, T fovr, T fovb, T fovt, T asp, T n, T f){
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T l = n * std::tan(fovl);
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T r = n * std::tan(fovr);
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T b = n * std::tan(fovb);
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T t = n * std::tan(fovt);
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return matrix<T,4,4>(((T{2} * n) / (r - l)) * asp, T{0}, T{0}, T{0},
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T{0}, (T{2} * n) / (t - b), T{0}, T{0},
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(r + l) / (r - l), (t + b) / (t - b), (f + n) / (n - f), -T{1},
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T{0}, T{0}, (T{2} * n * f) / (n - f), T{0});
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}
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template<typename T>
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matrix<T,4,4> ortho_projection(T w, T h, T n, T f){
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return matrix<T,4,4>(T{2} / w, T{0}, T{0}, T{0},
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T{0}, T{2} / h, T{0}, T{0},
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T{0}, T{0}, T{2} / (n - f), T{0},
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T{0}, T{0}, (n + f) / (n - f), T{1});
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}
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template<typename T>
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matrix<T,4,4> ortho_asymetric_projection(T l, T r, T b, T t, T n, T f){
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return matrix<T,4,4>(T{2} / (r - l), T{0}, T{0}, T{0},
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T{0}, T{2} / (t - b), T{0}, T{0},
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T{0}, T{0}, T{2} / (n - f), T{0},
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(r + l) / (l - r), (t + b) / (b - t), (n + f) / (n - f), T{1});
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}
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template<typename T>
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vec3<T> project(const mat4<T>& viewproj_mat, const vec3<T>& w_coords, const vec4<T>& viewport){
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//project world coordinates to ndc coordinates
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vec4<T> world_coords{w_coords[0], w_coords[1], w_coords[2], T{1.0}};
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vec4<T> ndc_coords = viewproj_mat * world_coords;
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//perspective_division
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ndc_coords /= ndc_coords[3];
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//project ndc coordinates to viewport coordinates
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return vec3<T>{((ndc_coords[0] + T{1.0}) * viewport[2] * T{0.5}) + viewport[0],
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((ndc_coords[1] + T{1.0}) * viewport[3] * T{0.5}) + viewport[1],
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ndc_coords[2]
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};
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}
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template<typename T>
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vec3<T> unproject(const mat4<T>& viewproj_mat, const vec3<T>& viewport_coords, const vec4<T>& viewport){
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//project viewport coordinates to ndc coordinates
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vec4<T> ndc_coords{((viewport_coords[0] - viewport[0]) * T{2.0} / viewport[2]) - T{1.0},
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((viewport_coords[1] - viewport[1]) * T{2.0} / viewport[3]) - T{1.0},
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viewport_coords[2],
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T{1.0}};
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//project ndc coordinates to world coordinates
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mat4<T> inv_viewproj_mat = viewproj_mat.inverse();
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vec4<T> world_coords = inv_viewproj_mat * ndc_coords;
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//perspective division
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world_coords /= world_coords[3];
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return {world_coords[0], world_coords[1], world_coords[2]};
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}
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}
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#endif
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