Unify behavior of union for import and add volume

Add cache for final ExPolygons

src/libslic3r/Emboss.cpp

@@ -448,7 +448,10 @@ HealedExPolygons Emboss::heal_polygons(const Polygons &shape, bool is_non_zero,
     Polygons polygons = to_polygons(paths);
     polygons.erase(std::remove_if(polygons.begin(), polygons.end(), 
         [](const Polygon &p) { return p.size() < 3; }), polygons.end());
-                
+    
+    if (polygons.empty())
+        return {{}, false};
+
     // Do not remove all duplicates but do it better way
     // Overlap all duplicit points by rectangle 3x3
     Points duplicits = collect_duplicates(to_points(polygons));
@@ -1280,23 +1283,8 @@ ExPolygons letter2shapes(
 const int CANCEL_CHECK = 10;
 } // namespace
 
-/// Union shape defined by glyphs
-HealedExPolygons Slic3r::union_ex(const ExPolygonsWithIds &shapes, unsigned max_heal_iteration)
-{
-    // unify to one expolygon
-    ExPolygons result;
-    for (const ExPolygonsWithId &shape : shapes) {
-        if (shape.expoly.empty())
-            continue;
-        expolygons_append(result, shape.expoly);
-    }
-    result = union_ex(result);
-
-    bool is_healed = heal_expolygons(result, max_heal_iteration);
-    return {result, is_healed};
-}
-
-HealedExPolygons Slic3r::union_with_delta(const ExPolygonsWithIds &shapes, float delta, unsigned max_heal_iteration)
+namespace {
+HealedExPolygons union_with_delta(const ExPolygonsWithIds &shapes, float delta, unsigned max_heal_iteration)
 {
     // unify to one expolygons
     ExPolygons expolygons;
@@ -1306,10 +1294,26 @@ HealedExPolygons Slic3r::union_with_delta(const ExPolygonsWithIds &shapes, float
         expolygons_append(expolygons, offset_ex(shape.expoly, delta));
     }
     ExPolygons result = union_ex(expolygons);
-    result         = offset_ex(result, -delta);
-    bool is_healed = heal_expolygons(result, max_heal_iteration);
+    result            = offset_ex(result, -delta);
+    bool is_healed    = heal_expolygons(result, max_heal_iteration);
     return {result, is_healed};
 }
+} // namespace
+
+ExPolygons Slic3r::union_with_delta(EmbossShape &shape, float delta, unsigned max_heal_iteration) 
+{
+    if (!shape.final_shape.empty())
+        return shape.final_shape;
+
+    HealedExPolygons result = ::union_with_delta(shape.shapes_with_ids, delta, max_heal_iteration);
+    shape.is_healed = result.is_healed;
+    for (const ExPolygonsWithId &e : shape.shapes_with_ids)
+        if (!e.is_healed)
+            shape.is_healed = false;
+    shape.final_shape = std::move(result.expolygons); // cached
+
+    return shape.final_shape;
+}
 
 void Slic3r::translate(ExPolygonsWithIds &expolygons_with_ids, const Point &p)
 {
@@ -1337,7 +1341,7 @@ HealedExPolygons Emboss::text2shapes(FontFileWithCache &font_with_cache, const c
     ExPolygonsWithIds vshapes = text2vshapes(font_with_cache, text_w, font_prop, was_canceled);
 
     float delta = static_cast<float>(1. / SHAPE_SCALE);
-    return union_with_delta(vshapes, delta, MAX_HEAL_ITERATION_OF_TEXT);
+    return ::union_with_delta(vshapes, delta, MAX_HEAL_ITERATION_OF_TEXT);
 }
 
 namespace {

src/libslic3r/Emboss.hpp

@@ -31,6 +31,9 @@ struct HealedExPolygons{
 /// </summary>
 namespace Emboss
 {    
+    static const float UNION_DELTA = 50.0f; // [approx in nano meters depends on volume scale]
+    static const unsigned UNION_MAX_ITERATIN = 10; // [count]
+
     /// <summary>
     /// Collect fonts registred inside OS
     /// </summary>
@@ -474,9 +477,8 @@ namespace Emboss
 void translate(ExPolygonsWithIds &e, const Point &p);
 BoundingBox get_extents(const ExPolygonsWithIds &e);
 void center(ExPolygonsWithIds &e);
-HealedExPolygons union_ex(const ExPolygonsWithIds &shapes, unsigned max_heal_iteration);
 // delta .. safe offset before union (use as boolean close)
 // NOTE: remove unprintable spaces between neighbor curves (made by linearization of curve)
-HealedExPolygons union_with_delta(const ExPolygonsWithIds &shapes, float delta, unsigned max_heal_iteration);
+ExPolygons union_with_delta(EmbossShape &shape, float delta, unsigned max_heal_iteration);
 } // namespace Slic3r
 #endif // slic3r_Emboss_hpp_

src/libslic3r/EmbossShape.hpp

@@ -74,6 +74,7 @@ struct EmbossShape
 {
     // shapes to to emboss separately over surface
     ExPolygonsWithIds shapes_with_ids;
+    ExPolygons final_shape; // When not set it is calculated from ExPolygonsWithIds
 
     // scale of shape, multiplier to get 3d point in mm from integer shape
     double scale = SCALING_FACTOR;

src/libslic3r/Format/3mf.cpp

@@ -3899,7 +3899,7 @@ std::optional<EmbossShape> read_emboss_shape(const char **attributes, unsigned i
     ExPolygonsWithIds shapes; // TODO: need to implement 
 
     EmbossShape::SvgFile svg{file_path, file_path_3mf};
-    return EmbossShape{shapes, scale, std::move(projection), std::move(fix_tr_mat), std::move(svg), is_healed};
+    return EmbossShape{shapes, {}, scale, std::move(projection), std::move(fix_tr_mat), std::move(svg), is_healed};
 }
 
 

src/libslic3r/Format/SVG.cpp

@@ -70,11 +70,8 @@ bool load_svg(const std::string &input_file, Model &output_model)
     emboss_shape.svg_file = std::move(svg_file);
 
     // unify to one expolygons
-    double delta = 1e-3; // in mm
-    unsigned max_heal_iteration = 10;
-    HealedExPolygons union_shape = union_with_delta(emboss_shape.shapes_with_ids, delta, max_heal_iteration);
-    if (!union_shape.is_healed)
-        BOOST_LOG_TRIVIAL(warning) << "SVG file(\"" << input_file << "\") couldn't be fully healed.";
+    // EmbossJob.cpp --> ExPolygons create_shape(DataBase &input, Fnc was_canceled) {
+    ExPolygons union_shape = union_with_delta(emboss_shape, Emboss::UNION_DELTA, Emboss::UNION_MAX_ITERATIN);
 
     // create projection
     double scale = emboss_shape.scale;
@@ -84,7 +81,7 @@ bool load_svg(const std::string &input_file, Model &output_model)
     Emboss::ProjectTransform project(std::move(projectZ), tr);
 
     // convert 2d shape to 3d triangles
-    indexed_triangle_set its = Emboss::polygons2model(union_shape.expolygons, project);
+    indexed_triangle_set its = Emboss::polygons2model(union_shape, project);
     TriangleMesh triangl_mesh(std::move(its));
 
     // add mesh to model

src/slic3r/GUI/Gizmos/GLGizmoSVG.cpp

@@ -907,6 +907,19 @@ void draw_filled(const ExPolygons &shape, const std::array<unsigned char, N>& co
     }  
 }
 
+/// Union shape defined by glyphs
+ExPolygons union_ex(const ExPolygonsWithIds &shapes)
+{
+    // unify to one expolygon
+    ExPolygons result;
+    for (const ExPolygonsWithId &shape : shapes) {
+        if (shape.expoly.empty())
+            continue;
+        expolygons_append(result, shape.expoly);
+    }
+    return union_ex(result);
+}
+
 // init texture by draw expolygons into texture
 bool init_texture(Texture &texture, const ExPolygonsWithIds& shapes_with_ids, unsigned max_size_px, const std::vector<std::string>& shape_warnings){
     BoundingBox bb = get_extents(shapes_with_ids);
@@ -933,10 +946,7 @@ bool init_texture(Texture &texture, const ExPolygonsWithIds& shapes_with_ids, un
     std::vector<unsigned char> data(n_pixels * channels_count, {0});
 
     // Union All shapes
-    ExPolygons shape;
-    for (const ExPolygonsWithId &shapes_with_id : shapes_with_ids)
-        expolygons_append(shape, shapes_with_id.expoly);
-    shape = union_ex(shape);
+    ExPolygons shape = union_ex(shapes_with_ids);
 
     // align to texture
     translate(shape, -bb.min);

src/slic3r/GUI/Jobs/EmbossJob.cpp

@@ -793,14 +793,10 @@ bool check(const UpdateSurfaceVolumeData &input, bool is_main_thread)
 template<typename Fnc> 
 ExPolygons create_shape(DataBase &input, Fnc was_canceled) {
     EmbossShape &es = input.create_shape();
-    float delta = 50.f;
-    unsigned max_heal_iteration = 10;    
-    HealedExPolygons result = union_with_delta(es.shapes_with_ids, delta, max_heal_iteration);
-    es.is_healed = result.is_healed;
-    for (const ExPolygonsWithId &e : es.shapes_with_ids)
-        if (!e.is_healed)
-            es.is_healed = false;
-    return result.expolygons;
+    // TODO: improve to use real size of volume
+    // ... need world matrix for volume
+    // ... printer resolution will be fine too
+    return union_with_delta(es, UNION_DELTA, UNION_MAX_ITERATIN);
 }
 
 //#define STORE_SAMPLING