Added intersects aabb for cylinder

src/typed-geometry/functions/objects/closest_points.hh

@@ -5,6 +5,7 @@
 #include <typed-geometry/types/pos.hh>
 #include <typed-geometry/types/quadric.hh>
 
+#include "coordinates.hh"
 #include "project.hh"
 
 // closest_points(a, b) returns points {p_a, p_b} such that contains(a, p_a) and contains(b, p_b) and |p_a - p_b| is minimal
@@ -51,6 +52,17 @@ template <class ScalarT>
     return {l0[t0], l1[t1]};
 }
 
+template <class ScalarT>
+[[nodiscard]] constexpr pair<ScalarT, ScalarT> closest_points_parameters(segment<3, ScalarT> const& s, line<3, ScalarT> const& l)
+{
+    auto ls = inf_of(s);
+    auto len = length(s);
+
+    auto [ts, tl] = closest_points_parameters(ls, l);
+    auto tClamped = clamp(ts, ScalarT(0), len);
+    return {tClamped / len, coordinates(l, ls[tClamped])};
+}
+
 
 // =========== Other Implementations ===========
 

src/typed-geometry/functions/objects/intersection.hh

@@ -26,6 +26,7 @@
 #include <typed-geometry/functions/vector/length.hh>
 
 #include "aabb.hh"
+#include "closest_points.hh"
 #include "contains.hh"
 #include "coordinates.hh"
 #include "direction.hh"
@@ -1543,6 +1544,48 @@ template <class ScalarT>
     return false;
 }
 
+template <class ScalarT>
+[[nodiscard]] constexpr bool intersects(cylinder<3, ScalarT> const& c, aabb<3, ScalarT> const& b)
+{
+    if (!intersects(aabb_of(c), b))
+        return false;
+
+    // check if the line through the axis intersects the aabb
+    auto const line = inf_of(c.axis);
+    auto const len = length(c.axis);
+    auto const hits = intersection_parameter(line, boundary_of(b));
+    if (hits.any())
+    {
+        auto const t = clamp(hits.first(), ScalarT(0), len);
+        for (auto const& hit : hits)
+        {
+            if (ScalarT(0) <= hit && hit <= len)
+                return true; // cylinder axis intersects aabb
+
+            if (t != clamp(hit, ScalarT(0), len))
+                return true; // intersections before and after the axis can only occur if it lies within aabb
+        }
+        return intersects(sphere<2, ScalarT, 3>(line[t], c.radius, line.dir), b);
+    }
+
+    // test disks at both cylinder ends
+    if (intersects(sphere<2, ScalarT, 3>(c.axis.pos0, c.radius, line.dir), b) || //
+        intersects(sphere<2, ScalarT, 3>(c.axis.pos1, c.radius, line.dir), b))
+        return true;
+
+    // now only intersections between aabb edges and cylinder mantle remain
+    auto const r2 = c.radius * c.radius;
+    for (auto const& edge : edges_of(b))
+    {
+        auto [te, tl] = closest_points_parameters(edge, line);
+        if (ScalarT(0) < tl && tl < len && distance_sqr(edge[te], line[tl]) <= r2)
+            return true;
+    }
+
+    return false;
+}
+// TODO: cylinder_boundary_no_caps
+
 template <int D, class ScalarT>
 [[nodiscard]] constexpr bool intersects(inf_cylinder<D, ScalarT> const& c, aabb<D, ScalarT> const& b)
 {