From 54ee39ffd75421c4489d2b473de4a65ff541f21c Mon Sep 17 00:00:00 2001 From: Dan Goodliffe Date: Mon, 29 Aug 2022 19:57:43 +0100 Subject: Ray function a calculate how close it passes to a line defined by 2 points --- lib/ray.cpp | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 lib/ray.cpp (limited to 'lib/ray.cpp') diff --git a/lib/ray.cpp b/lib/ray.cpp new file mode 100644 index 0000000..1e30ae4 --- /dev/null +++ b/lib/ray.cpp @@ -0,0 +1,18 @@ +#include "ray.hpp" + +float +Ray::distanceToLine(const glm::vec3 & p1, const glm::vec3 & e1) const +{ + // https://en.wikipedia.org/wiki/Skew_lines + const auto diff = p1 - e1; + const auto d1 = glm::normalize(diff); + const auto &p2 = start, &d2 = direction; + const auto n = glm::cross(d1, d2); + const auto n2 = glm::cross(d2, n); + const auto c1 = p1 + (glm::dot((p2 - p1), n2) / glm::dot(d1, n2)) * d1; + const auto difflength = glm::length(diff); + if (glm::length(c1 - p1) > difflength || glm::length(c1 - e1) > difflength) { + return std::numeric_limits::infinity(); + } + return glm::abs(glm::dot(n, p1 - p2)); +} -- cgit v1.2.3