diff options
| -rw-r--r-- | lib/ray.cpp | 18 | ||||
| -rw-r--r-- | lib/ray.hpp | 2 | ||||
| -rw-r--r-- | test/test-maths.cpp | 29 |
3 files changed, 49 insertions, 0 deletions
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<float>::infinity(); + } + return glm::abs(glm::dot(n, p1 - p2)); +} diff --git a/lib/ray.hpp b/lib/ray.hpp index 4c0710a..bce4a30 100644 --- a/lib/ray.hpp +++ b/lib/ray.hpp @@ -8,4 +8,6 @@ public: glm::vec3 start; glm::vec3 direction; + + float distanceToLine(const glm::vec3 & a, const glm::vec3 & b) const; }; diff --git a/test/test-maths.cpp b/test/test-maths.cpp index 1f2a096..70cf206 100644 --- a/test/test-maths.cpp +++ b/test/test-maths.cpp @@ -287,3 +287,32 @@ BOOST_AUTO_TEST_CASE(camera_clicks) BOOST_CHECK_CLOSE_VEC(camera.unProject({right, centre}).direction, glm::normalize(::north)); BOOST_CHECK_CLOSE_VEC(camera.unProject({left, centre}).direction, glm::normalize(::west)); } + +template<typename T = float> +auto +n_test_points_between(std::size_t n = 2, T min = -100.F, T max = 100.F) +{ + return boost::unit_test::data::xrange(n) ^ boost::unit_test::data::random(min, max); +} + +BOOST_DATA_TEST_CASE(rayLineDistance, + n_test_points_between() * // n1x + n_test_points_between() * // n1y + n_test_points_between() * // n1z + n_test_points_between() * // n2x + n_test_points_between() * // n2y + n_test_points_between() * // n2z + n_test_points_between() * // cx + n_test_points_between() * // cy + n_test_points_between(), // cz + i1, n1x, i2, n1y, i3, n1z, i4, n2x, i5, n2y, i6, n2z, i7, cx, i8, cy, i9, cz) +{ + const glm::vec3 n1 {n1x, n1y, n1z}, n2 {n2x, n2y, n2z}, c {cx, cy, cz}; + + const auto nstep = n2 - n1; + for (float along = 0.2F; along <= 0.8F; along += 0.1F) { + const auto target = n1 + (along * nstep); + const auto direction = glm::normalize(target - c); + BOOST_CHECK_LE(Ray(c, direction).distanceToLine(n1, n2), 0.01F); + } +} |