{"description":"#include <Siv3D.hpp> const double eps = 1e-8; bool isZero(const Vec2& v) { return v.length() < eps; } bool operator||(const Vec2& v1, const Vec2& v2) { return !isZero(v1) && !isZero(v2) && (1.0 - eps) < Abs(v1.normalized().dot(v2.normalized())); } void Main() { const Vec2 v1(1, 0), v2(-1, 0), v3(1, \u2026","blog_url":"https://agehama.hatenablog.com/","provider_name":"Hatena Blog","author_name":"agehama","url":"https://agehama.hatenablog.com/entry/2014/03/20/224551","published":"2014-03-20 22:45:51","provider_url":"https://hatena.blog","image_url":null,"width":"100%","author_url":"https://blog.hatena.ne.jp/agehama/","categories":["Siv3D","\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0"],"html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fagehama.hatenablog.com%2Fentry%2F2014%2F03%2F20%2F224551\" title=\"\u5e73\u884c - agehama&#39;s diary\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","height":"190","version":"1.0","blog_title":"agehama's diary","type":"rich","title":"\u5e73\u884c"}