Useful backend improvements from sla volumes branch

src/libslic3r/CSGMesh/ModelToCSGMesh.hpp

@@ -0,0 +1,58 @@
+#ifndef MODELTOCSGMESH_HPP
+#define MODELTOCSGMESH_HPP
+
+#include "CSGMesh.hpp"
+
+#include "libslic3r/Model.hpp"
+#include "libslic3r/SLA/Hollowing.hpp"
+
+namespace Slic3r { namespace csg {
+
+enum ModelParts {
+    mpartsPositive = 1,
+    mpartsNegative = 2,
+    mpartsDrillHoles = 4
+};
+
+template<class OutIt>
+void model_to_csgmesh(const ModelObject &mo,
+                      const Transform3d &trafo,
+                      OutIt              out,
+                      // values of ModelParts ORed
+                      int                parts_to_include = mpartsPositive
+                      )
+{
+    bool do_positives = parts_to_include & mpartsPositive;
+    bool do_negatives = parts_to_include & mpartsNegative;
+    bool do_drillholes = parts_to_include & mpartsDrillHoles;
+
+    for (const ModelVolume *vol : mo.volumes) {
+        if (vol && vol->mesh_ptr() &&
+            ((do_positives && vol->is_model_part()) ||
+             (do_negatives && vol->is_negative_volume()))) {
+            CSGPart part{&(vol->mesh().its),
+                vol->is_model_part() ? CSGType::Union : CSGType::Difference,
+             (trafo * vol->get_matrix()).cast<float>()};
+
+            *out = std::move(part);
+            ++out;
+        }
+    }
+
+    if (do_drillholes) {
+        sla::DrainHoles drainholes = sla::transformed_drainhole_points(mo, trafo);
+
+        for (const sla::DrainHole &dhole : drainholes) {
+            CSGPart part{std::make_unique<const indexed_triangle_set>(
+                             dhole.to_mesh()),
+                         CSGType::Difference};
+
+            *out = std::move(part);
+            ++out;
+        }
+    }
+}
+
+}} // namespace Slic3r::csg
+
+#endif // MODELTOCSGMESH_HPP