Add tests for EigenMesh3D raycaster with hole support.

Tests fail! Supports are intersecting the object when holes are added.

tests/sla_print/sla_raycast_tests.cpp

@@ -0,0 +1,61 @@
+#include <catch2/catch.hpp>
+#include <test_utils.hpp>
+
+#include <libslic3r/SLA/EigenMesh3D.hpp>
+#include <libslic3r/SLA/Hollowing.hpp>
+
+#include "sla_test_utils.hpp"
+
+using namespace Slic3r;
+
+// Create a simple scene with a 20mm cube and a big hole in the front wall 
+// with 5mm radius. Then shoot rays from interesting positions and see where
+// they land.
+TEST_CASE("Raycaster with loaded drillholes", "[sla_raycast]") 
+{
+    // Load the cube and make it hollow.
+    TriangleMesh cube = load_model("20mm_cube.obj");
+    sla::HollowingConfig hcfg;
+    std::unique_ptr<TriangleMesh> cube_inside = sla::generate_interior(cube, hcfg);
+    REQUIRE(cube_inside);
+    
+    // Helper bb
+    auto boxbb = cube.bounding_box();
+    
+    // Create the big 10mm long drainhole in the front wall.
+    Vec3f center = boxbb.center().cast<float>();
+    Vec3f p = {center.x(), 0., center.z()};
+    Vec3f normal = {0.f, 1.f, 0.f};
+    float radius = 5.f;
+    float hole_length = 10.;
+    sla::DrainHoles holes = { sla::DrainHole{p, normal, radius, hole_length} };
+    
+    cube.merge(*cube_inside);
+    cube.require_shared_vertices();
+    
+    sla::EigenMesh3D emesh{cube};
+    emesh.load_holes(holes);
+    
+    Vec3d s = center.cast<double>();
+    SECTION("Fire from center, should hit the interior wall") {
+        auto hit = emesh.query_ray_hit(s, {0, 1., 0.});
+        REQUIRE(hit.distance() == Approx(boxbb.size().x() / 2 - hcfg.min_thickness));
+    }
+    
+    SECTION("Fire upward from hole center, hit distance equals the radius") {
+        s.y() = hcfg.min_thickness / 2;
+        auto hit = emesh.query_ray_hit(s, {0, 0., 1.});
+        REQUIRE(hit.distance() == Approx(radius));
+    }
+    
+    // Shouldn't this hit the inside wall through the hole?
+    SECTION("Fire from outside, hit the back side of the hole cylinder.") {
+        s.y() = -1.;
+        auto hit = emesh.query_ray_hit(s, {0, 1., 0.});
+        REQUIRE(hit.distance() == Approx(hole_length + 1.f));
+    }
+    
+    SECTION("Check for support tree correctness") {
+        test_support_model_collision("20mm_cube.obj", {}, hcfg, holes);
+    }
+}