ENH: add bridge direction option

In some complicated cases or irregular shape, the direction
of external bridge is not good when calculated automaticlly.
So user may use modifier to change bridge direction.

This is handling for github issue #340

Signed-off-by: salt.wei <salt.wei@bambulab.com>
Change-Id: I3baf313f47925fa7e6aa087f5896b0af560f902d

src/libslic3r/LayerRegion.cpp

@@ -295,8 +295,7 @@ void LayerRegion::process_external_surfaces(const Layer *lower_layer, const Poly
                 #ifdef SLIC3R_DEBUG
                 printf("Processing bridge at layer %zu:\n", this->layer()->id());
                 #endif
-                //BBS: use 0 as custom angle to enable auto detection all the time
-				double custom_angle = Geometry::deg2rad(0.0);
+				double custom_angle = Geometry::deg2rad(this->region().config().bridge_angle.value);
 				if (bd.detect_angle(custom_angle)) {
                     bridges[idx_last].bridge_angle = bd.angle;
                     if (this->layer()->object()->has_support()) {

src/libslic3r/Preset.cpp

@@ -694,7 +694,7 @@ static std::vector<std::string> s_Preset_print_options {
     "top_shell_layers", "top_shell_thickness", "bottom_shell_layers", "bottom_shell_thickness",
     "reduce_crossing_wall", "detect_thin_wall", "detect_overhang_wall",
     "seam_position", "wall_infill_order", "sparse_infill_density", "sparse_infill_pattern", "top_surface_pattern", "bottom_surface_pattern",
-    "infill_direction",
+    "infill_direction", "bridge_angle",
     "minimum_sparse_infill_area", "reduce_infill_retraction",
     "ironing_type", "ironing_flow", "ironing_speed", "ironing_spacing",
     "max_travel_detour_distance",

src/libslic3r/PrintConfig.cpp

@@ -644,6 +644,17 @@ void PrintConfigDef::init_fff_params()
     def->enum_labels.emplace_back("95%");
     def->set_default_value(new ConfigOptionEnumsGeneric{ (int)Overhang_threshold_bridge });
 
+    def = this->add("bridge_angle", coFloat);
+    def->label = L("Bridge direction");
+    def->category = L("Strength");
+    def->tooltip = L("Bridging angle override. If left to zero, the bridging angle will be calculated "
+        "automatically. Otherwise the provided angle will be used for external bridges. "
+        "Use 180°for zero angle.");
+    def->sidetext = L("°");
+    def->min = 0;
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionFloat(0.));
+
     def = this->add("bridge_flow", coFloat);
     def->label = L("Bridge flow");
     def->category = L("Quality");

src/libslic3r/PrintConfig.hpp

@@ -658,6 +658,7 @@ PRINT_CONFIG_CLASS_DEFINE(
 
     ((ConfigOptionInt,                  bottom_shell_layers))
     ((ConfigOptionFloat,                bottom_shell_thickness))
+    ((ConfigOptionFloat,                bridge_angle))
     ((ConfigOptionFloat,                bridge_flow))
     ((ConfigOptionFloat,                bridge_speed))
     ((ConfigOptionEnum<InfillPattern>,  top_surface_pattern))

src/libslic3r/PrintObject.cpp

@@ -769,7 +769,8 @@ bool PrintObject::invalidate_state_by_config_options(
             || opt_key == "minimum_sparse_infill_area"
             || opt_key == "sparse_infill_filament"
             || opt_key == "solid_infill_filament"
-            || opt_key == "sparse_infill_line_width") {
+            || opt_key == "sparse_infill_line_width"
+            || opt_key == "bridge_angle") {
             steps.emplace_back(posPrepareInfill);
         } else if (
                opt_key == "top_surface_pattern"

src/slic3r/GUI/ConfigManipulation.cpp

@@ -488,7 +488,7 @@ void ConfigManipulation::toggle_print_fff_options(DynamicPrintConfig *config, co
     for (auto el : { "top_surface_pattern", "bottom_surface_pattern", "solid_infill_filament"})
         toggle_field(el, has_solid_infill);
 
-    for (auto el : { "infill_direction", "sparse_infill_line_width",
+    for (auto el : { "infill_direction", "sparse_infill_line_width", "bridge_angle",
                     "sparse_infill_speed", "bridge_speed" })
         toggle_field(el, have_infill || has_solid_infill);
 

src/slic3r/GUI/GUI_Factories.cpp

@@ -94,7 +94,7 @@ std::map<std::string, std::vector<SimpleSettingData>>  SettingsFactory::PART_CAT
     { L("Strength"), {{"wall_loops", "",1},{"top_shell_layers", L("Top Solid Layers"),1},{"top_shell_thickness", L("Top Minimum Shell Thickness"),1},
                     {"bottom_shell_layers", L("Bottom Solid Layers"),1}, {"bottom_shell_thickness", L("Bottom Minimum Shell Thickness"),1},
                     {"sparse_infill_density", "",1},{"sparse_infill_pattern", "",1},{"top_surface_pattern", "",1},{"bottom_surface_pattern", "",1},
-                    {"infill_combination", "",1}, {"infill_wall_overlap", "",1}, {"infill_direction", "",1}, {"minimum_sparse_infill_area", "",1}
+                    {"infill_combination", "",1}, {"infill_wall_overlap", "",1}, {"infill_direction", "",1}, {"bridge_angle", "",1},{"minimum_sparse_infill_area", "",1}
                     }},
     { L("Speed"), {{"outer_wall_speed", "",1},{"inner_wall_speed", "",2},{"sparse_infill_speed", "",3},{"top_surface_speed", "",4}, {"internal_solid_infill_speed", "",5},
                     {"enable_overhang_speed", "",6}, {"overhang_1_4_speed", "",7}, {"overhang_2_4_speed", "",8}, {"overhang_3_4_speed", "",9}, {"overhang_4_4_speed", "",10},

src/slic3r/GUI/Tab.cpp

@@ -1805,6 +1805,7 @@ void TabPrint::build()
         optgroup = page->new_optgroup(L("Advanced"), L"param_advanced");
         optgroup->append_single_option_line("infill_wall_overlap");
         optgroup->append_single_option_line("infill_direction");
+        optgroup->append_single_option_line("bridge_angle");
         optgroup->append_single_option_line("minimum_sparse_infill_area");
         optgroup->append_single_option_line("infill_combination");
         optgroup->append_single_option_line("detect_narrow_internal_solid_infill");