WIP: own AABBTreeIndirect, builds up the tree 4x quicker than libigl.

tests/libslic3r/CMakeLists.txt

@@ -3,6 +3,7 @@ get_filename_component(_TEST_NAME ${CMAKE_CURRENT_LIST_DIR} NAME)
 add_executable(${_TEST_NAME}_tests 
 	${_TEST_NAME}_tests.cpp
 	test_3mf.cpp
+	test_aabbindirect.cpp
 	test_clipper_offset.cpp
 	test_clipper_utils.cpp
 	test_config.cpp

tests/libslic3r/test_aabbindirect.cpp

@@ -0,0 +1,61 @@
+#include <catch2/catch.hpp>
+#include <test_utils.hpp>
+
+#include <libslic3r/TriangleMesh.hpp>
+#include <libslic3r/AABBTreeIndirect.hpp>
+
+using namespace Slic3r;
+
+TEST_CASE("Building a tree over a box, ray caster and closest query", "[AABBIndirect]")
+{
+    TriangleMesh tmesh = make_cube(1., 1., 1.);
+    tmesh.repair();
+
+    auto tree = AABBTreeIndirect::build_aabb_tree(tmesh.its.vertices, tmesh.its.indices);
+    REQUIRE(! tree.empty());
+
+    igl::Hit hit;
+	bool intersected = AABBTreeIndirect::intersect_ray_first_hit(
+		tmesh.its.vertices, tmesh.its.indices,
+		tree,
+		Vec3d(0.5, 0.5, -5.),
+		Vec3d(0., 0., 1.),
+		hit);
+
+    REQUIRE(intersected);
+    REQUIRE(hit.t == Approx(5.));
+
+    std::vector<igl::Hit> hits;
+	bool intersected2 = AABBTreeIndirect::intersect_ray_all_hits(
+		tmesh.its.vertices, tmesh.its.indices,
+		tree,
+        Vec3d(0.3, 0.5, -5.),
+		Vec3d(0., 0., 1.),
+		hits);
+    REQUIRE(intersected2);
+    REQUIRE(hits.size() == 2);
+    REQUIRE(hits.front().t == Approx(5.));
+    REQUIRE(hits.back().t == Approx(6.));
+
+    size_t hit_idx;
+    Vec3d  closest_point;
+    double squared_distance = AABBTreeIndirect::squared_distance(
+		tmesh.its.vertices, tmesh.its.indices,
+		tree,
+        Vec3d(0.3, 0.5, -5.),
+		hit_idx, closest_point);
+    REQUIRE(squared_distance == Approx(5. * 5.));
+    REQUIRE(closest_point.x() == Approx(0.3));
+    REQUIRE(closest_point.y() == Approx(0.5));
+    REQUIRE(closest_point.z() == Approx(0.));
+
+    squared_distance = AABBTreeIndirect::squared_distance(
+		tmesh.its.vertices, tmesh.its.indices,
+		tree,
+        Vec3d(0.3, 0.5, 5.),
+		hit_idx, closest_point);
+    REQUIRE(squared_distance == Approx(4. * 4.));
+    REQUIRE(closest_point.x() == Approx(0.3));
+    REQUIRE(closest_point.y() == Approx(0.5));
+    REQUIRE(closest_point.z() == Approx(1.));
+}