28 lines
641 B
C++
28 lines
641 B
C++
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#include "imgui_plot.h"
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namespace ImGui
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{
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bool is_inside_area(const ImVec2& P, const ImVector<ImVec2>& V)
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{
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size_t cn = 0; // the crossing number counter
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size_t n = V.size();
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if (n < 3) return false;
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size_t i = 0;
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size_t j = 1;
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while (i < n) {
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if (((V[i].y <= P.y) && (V[j].y > P.y)) || ((V[i].y > P.y) && (V[j].y <= P.y))) {
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float vt = (float)(P.y - V[i].y) / (V[j].y - V[i].y);
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if (P.x < V[i].x + vt * (V[j].x - V[i].x)) { // P.x < intersect
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++cn; // a valid crossing of y=P.y right of P.x
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}
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}
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++i;
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j = (i + 1) % n;
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}
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return cn % 2 != 0; // false if even (out), and true if odd (in)
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}
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}
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