79 lines
2.0 KiB
C++
79 lines
2.0 KiB
C++
//
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// Created by Иван Ильин on 19.01.2021.
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//
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#include "Plane.h"
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Plane::Plane(const Triangle& tri) {
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_triangle = tri;
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_n = tri.norm();
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_p = tri[0];
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}
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Plane::Plane(const Point4D &N, const Point4D &P) {
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_n = N.normalized();
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_p = P;
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}
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Plane::Plane(const Plane &plane) {
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_triangle = plane._triangle;
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_n = plane._n;
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_p = plane._p;
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}
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double Plane::distance(const Point4D &point4D) const {
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return point4D.dot(_n) - _p.dot(_n);
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}
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std::pair<Point4D, double> Plane::intersection(const Point4D &start, const Point4D &end) const {
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double s_dot_n = start.dot(_n);
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double k = (s_dot_n - _p.dot(_n)) / (s_dot_n - end.dot(_n));
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Point4D res = start + (end - start)*k;
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return std::make_pair(res, k);
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}
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int Plane::clip(Triangle &tri, Triangle &additional_tri) const {
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Point4D insidePoints[3]; int inside = 0;
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Point4D outsidePoints[3]; int outside = 0;
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double distances[3] = {distance(tri[0]), distance(tri[1]), distance(tri[2])};
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for(int i = 0; i < 3; i++) {
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if (distances[i] >= 0) {
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insidePoints[inside++] = tri[i];
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} else {
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outsidePoints[outside++] = tri[i];
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}
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}
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if(inside == 0) {
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return 0;
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}
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if(inside == 1) {
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std::pair<Point4D, double> intersect1 = intersection(insidePoints[0], outsidePoints[0]);
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std::pair<Point4D, double> intersect2 = intersection(insidePoints[0], outsidePoints[1]);
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tri = Triangle(insidePoints[0], intersect1.first, intersect2.first, tri.color());
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return 1;
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}
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if(inside == 2) {
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std::pair<Point4D, double> intersect1 = intersection(insidePoints[0], outsidePoints[0]);
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std::pair<Point4D, double> intersect2 = intersection(insidePoints[1], outsidePoints[0]);
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tri = Triangle(insidePoints[0], intersect1.first, insidePoints[1], tri.color());
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additional_tri = Triangle(intersect1.first, intersect2.first, insidePoints[1], tri.color());
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return 2;
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}
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if(inside == 3) {
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return 1;
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}
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return 0;
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}
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