Add geom::ray primitive

libs/geom/include/psemek/geom/ray.hpp

@@ -0,0 +1,59 @@
+#pragma once
+
+#include <psemek/geom/vector.hpp>
+#include <psemek/geom/point.hpp>
+
+namespace psemek::geom
+{
+
+	template <typename T, std::size_t N>
+	struct ray
+	{
+		point<T, N> origin;
+		vector<T, N> direction;
+
+		auto operator()(T const & t) const
+		{
+			return origin + t * direction;
+		}
+
+		ray & operator += (vector<T, N> const & v)
+		{
+			origin += v;
+			return *this;
+		}
+
+		ray & operator -= (vector<T, N> const & v)
+		{
+			origin -= v;
+			return *this;
+		}
+	};
+
+	template <typename T, std::size_t N>
+	ray(point<T, N>, vector<T, N>) -> ray<T, N>;
+
+	template <typename T, std::size_t N>
+	ray<T, N> advance(ray<T, N> r, T const & t)
+	{
+		r.origin = r(t);
+		return r;
+	}
+
+	template <typename T, std::size_t N>
+	ray<T, N> operator + (ray<T, N> const & r, vector<T, N> const & v)
+	{
+		auto res = r;
+		res += v;
+		return res;
+	}
+
+	template <typename T, std::size_t N>
+	ray<T, N> operator - (ray<T, N> const & r, vector<T, N> const & v)
+	{
+		auto res = r;
+		res -= v;
+		return res;
+	}
+
+}