Refactor infill rotation (#10587)

* refactor Infill rotation template

* clean up comments

* set default solid_infill_rotate_template to empty

* Fix an issue that infill_direction solid_infill_direction not working as expected

* update based on feedback

src/libslic3r/Fill/FillBase.hpp

@@ -119,8 +119,8 @@ public:
     coordf_t    overlap;
     // in radians, ccw, 0 = East
     float       angle;
-    // Orca: enable angle shifting for layer change
-    float        rotate_angle{ M_PI/180.0 };
+    // Orca: is_using_template_angle
+    bool        is_using_template_angle{false};
     // In scaled coordinates. Maximum lenght of a perimeter segment connecting two infill lines.
     // Used by the FillRectilinear2, FillGrid2, FillTriangles, FillStars and FillCubic.
     // If left to zero, the links will not be limited.
@@ -182,7 +182,6 @@ protected:
         overlap(0.),
         // Initial angle is undefined.
         angle(FLT_MAX),
-        rotate_angle(M_PI/180.0),
         link_max_length(0),
         loop_clipping(0),
         // The initial bounding box is empty, therefore undefined.
@@ -204,7 +203,7 @@ protected:
         ExPolygon                      expolygon,
         ThickPolylines& thick_polylines_out) {}
 
-    virtual float _layer_angle(size_t idx) const { return rotate_angle; }
+    virtual float _layer_angle(size_t idx) const { return is_using_template_angle ? 0.f : (idx & 1) ? float(M_PI/2.) : 0.f; }
 
     virtual std::pair<float, Point> _infill_direction(const Surface *surface) const;