92 lines
2.2 KiB
C++
92 lines
2.2 KiB
C++
#pragma once
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#ifndef UTILITY_H
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static float sign(float x, float y, float x1, float y1, float x2, float y2)
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{
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return (x - x2) * (y1 - y2) - (x1 - x2) * (y - y2);
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}
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static float sign (Point &p1, Point &p2, Point &p3)
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{
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return (p1.x() - p3.x()) * (p2.y() - p3.y()) - (p2.x() - p3.x()) * (p1.y() - p3.y());
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}
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static bool IsPointInTriangle(Point &pt, Point &p1, Point &p2, Point &p3)
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{
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float d1 = sign(pt, p1, p2);
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float d2 = sign(pt, p2, p3);
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float d3 = sign(pt, p3, p1);
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bool has_neg = (d1 < 0) || (d2 < 0) || (d3 < 0);
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bool has_pos = (d1 > 0) || (d2 > 0) || (d3 > 0);
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return !(has_neg && has_pos);
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}
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static float pDistance(float x, float y, float x1, float y1, float x2, float y2) {
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float A = x - x1;
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float B = y - y1;
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float C = x2 - x1;
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float D = y2 - y1;
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float dot = A * C + B * D;
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float len_sq = C * C + D * D;
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float param = -1;
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if (len_sq != 0) // in case of 0 length line
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param = dot / len_sq;
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float xx, yy;
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if (param < 0) {
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xx = x1;
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yy = y1;
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}
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else if (param > 1) {
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xx = x2;
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yy = y2;
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}
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else {
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xx = x1 + param * C;
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yy = y1 + param * D;
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}
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float dx = x - xx;
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float dy = y - yy;
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return dx * dx + dy * dy;
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//return sqrt(dx * dx + dy * dy);
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}
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/* not used anymore... or yet
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static bool SortForMinXMaxY (const Point& a, const Point& b)
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{
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if (a.x() != b.x())
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{
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return (a.x() < b.x());
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}
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return (a.y() > b.y());
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}
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static bool SortForMinYMaxX(const Point& a, const Point& b)
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{
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if (a.y() != b.y())
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{
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return (a.x() < b.x());
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}
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return (a.y() > b.y());
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}
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static void sortPoints (std::vector<Point>& pts)
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{
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std::sort(pts.begin(), pts.end(), SortForMinXMaxY);
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}
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// TODO: what happens if all/more points are on hor/vert line? -> sort for x, than y should handle this
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static std::pair<Point, Point> getMinMaxX(std::vector<Point>& pts)
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{
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// TODO: check if already sorted? assume array is sorted? call sort utility function???
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//sortPoints(pts);
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std::sort(pts.begin(), pts.end(), SortForMinXMaxY);
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return std::make_pair(pts[0], pts[pts.size() - 1]);
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}*/
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#endif // UTILITY_H
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