Split overhang angle w.r.t. seams off from overhang angle.

part of CURA-8076

include/LayerPlan.h

@@ -99,6 +99,7 @@ class LayerPlan : public NoCopy
     coord_t comb_move_inside_distance_; //!< Whenever using the minimum boundary for combing it tries to move the coordinates inside by this distance after calculating the combing.
     Shape bridge_wall_mask_; //!< The regions of a layer part that are not supported, used for bridging
     Shape overhang_mask_; //!< The regions of a layer part where the walls overhang
+    Shape seam_overhang_mask_; //!< The regions of a layer part where the walls overhang, specifically as defined for the seam
     Shape roofing_mask_; //!< The regions of a layer part where the walls are exposed to the air
 
     bool min_layer_time_used = false; //!< Wether or not the minimum layer time (cool_min_layer_time) was actually used in this layerplan.
@@ -283,6 +284,13 @@ class LayerPlan : public NoCopy
      */
     void setOverhangMask(const Shape& polys);
 
+    /*!
+     * Set seam_overhang_mask.
+     *
+     * \param polys The overhung areas of the part currently being processed that will require modified print settings w.r.t. seams
+     */
+    void setSeamOverhangMask(const Shape& polys);
+
     /*!
      * Set roofing_mask.
      *
@@ -671,12 +679,12 @@ class LayerPlan : public NoCopy
     template<typename T>
     unsigned locateFirstSupportedVertex(const T& wall, const unsigned start_idx) const
     {
-        if (bridge_wall_mask_.empty() && overhang_mask_.empty())
+        if (bridge_wall_mask_.empty() && seam_overhang_mask_.empty())
         {
             return start_idx;
         }
 
-        const auto air_below = bridge_wall_mask_.unionPolygons(overhang_mask_);
+        const auto air_below = bridge_wall_mask_.unionPolygons(seam_overhang_mask_);
 
         unsigned curr_idx = start_idx;
 

src/FffGcodeWriter.cpp

@@ -2691,6 +2691,19 @@ bool FffGcodeWriter::processInsets(
             gcode_layer.setOverhangMask(overhang_region);
         }
 
+        // As above, but for the seam overhang mask instead of the wall one.
+        const AngleDegrees seam_overhang_angle = mesh.settings.get<AngleDegrees>("seam_overhang_angle");
+        if (seam_overhang_angle >= 90)
+        {
+            gcode_layer.setSeamOverhangMask(Shape());
+        }
+        else
+        {
+            const coord_t overhang_width = layer_height * std::tan(seam_overhang_angle / (180 / std::numbers::pi));
+            Shape overhang_region = part.outline.offset(-half_outer_wall_width).difference(outlines_below.offset(10 + overhang_width - half_outer_wall_width)).offset(10);
+            gcode_layer.setSeamOverhangMask(overhang_region);
+        }
+
         const auto roofing_mask_fn = [&]() -> Shape
         {
             const size_t roofing_layer_count = std::min(mesh.settings.get<size_t>("roofing_layer_count"), mesh.settings.get<size_t>("top_layers"));
@@ -2721,6 +2734,8 @@ bool FffGcodeWriter::processInsets(
         gcode_layer.setBridgeWallMask(Shape());
         // clear to disable overhang detection
         gcode_layer.setOverhangMask(Shape());
+        // clear to disable overhang detection
+        gcode_layer.setSeamOverhangMask(Shape());
         // clear to disable use of roofing settings
         gcode_layer.setRoofingMask(Shape());
     }

src/LayerPlan.cpp

@@ -2689,6 +2689,11 @@ void LayerPlan::setOverhangMask(const Shape& polys)
     overhang_mask_ = polys;
 }
 
+void LayerPlan::setSeamOverhangMask(const Shape& polys)
+{
+    seam_overhang_mask_ = polys;
+}
+
 void LayerPlan::setRoofingMask(const Shape& polys)
 {
     roofing_mask_ = polys;