seam notch : allow almost convex/concave, so little imprecision doesn…

…'t prevent from detection.

set seam_notch_angle min value to 180, as it doesn't
#4143

src/libslic3r/GCode.cpp

@@ -4111,9 +4111,11 @@ void GCode::seam_notch(const ExtrusionLoop& original_loop,
                 bool is_convex = false;
                 if (is_hole_loop) {
                     //test if convex (as it's clockwise bc it's a hole, we have to do the opposite)
-                    is_convex = polygon_to_test.convex_points().empty();
+                    // 3.07 instead of PI to allow for some convex outliers (sometimes, stl can be a bit imprecise)
+                    is_convex = polygon_to_test.convex_points(3.07).empty();
                 } else {
-                    is_convex = polygon_to_test.concave_points().empty();
+                    // 3.3 instead of PI to allow for some concave outliers (sometimes, stl can be a bit imprecise)
+                    is_convex = polygon_to_test.concave_points(3.3).empty();
                 }
                 if (is_convex) {
                     // Computing circle center
@@ -4196,19 +4198,24 @@ void GCode::seam_notch(const ExtrusionLoop& original_loop,
 
         //check if the current angle isn't too sharp
         double check_angle = 0;
+        // get min angle (and if at min or max value, push it a bit more to avoid not filtering outliers)
+        double min_angle = this->m_config.seam_notch_angle.value;
+        if(min_angle <= 179.9) min_angle -= 1;
+        if(min_angle >= 359.9) min_angle += 1;
+        min_angle *= PI / 180.;
         if (end_point.distance_to_square(start_point) < SCALED_EPSILON * SCALED_EPSILON) {
             check_angle = start_point.ccw_angle(prev_point, next_point);
         } else {
             check_angle = end_point.ccw_angle(prev_point, start_point);
-            if ((is_hole_loop ? -check_angle : check_angle) > this->m_config.seam_notch_angle.value * PI / 180.) {
+            if ((is_hole_loop ? -check_angle : check_angle) > min_angle) {
                 BOOST_LOG_TRIVIAL(debug) << "notch abord: too big angle\n";
                 return;
             }
             check_angle = start_point.ccw_angle(end_point, next_point);
         }
         assert(end_point != start_point);
         assert(end_point != next_point);
-        if ((is_hole_loop ? -check_angle : check_angle) > this->m_config.seam_notch_angle.value * PI / 180.) {
+        if ((is_hole_loop ? -check_angle : check_angle) > min_angle) {
             BOOST_LOG_TRIVIAL(debug) << "notch abord: too big angle\n";
             return;
         }

src/libslic3r/PrintConfig.cpp

@@ -1889,7 +1889,7 @@ void PrintConfigDef::init_fff_params()
         "\nA value that only takes values as 'true' or 'false' will be a boolean)"
         "\nEvery other value will be parsed as a string as-is."
         "\nThese variables will be available as an array in the custom gcode (one item per extruder), don't forget to use them with the {current_extruder} index to get the current value."
-        " If a filament has a typo on the variable that change its type, then the parser will convert evrything to strings."
+        " If a filament has a typo on the variable that change its type, then the parser will convert everything to strings."
         "\nAdvice: before using a variable, it's safer to use the function 'default_XXX(variable_name, default_value)'"
         " (enclosed in bracket as it's a script) in case it's not set. You can replace XXX by 'int' 'bool' 'double' 'string'.");
     def->multiline = true;
@@ -4708,9 +4708,10 @@ void PrintConfigDef::init_fff_params()
     def->label = L("max angle");
     def->full_label = L("Seam notch maximum angle");
     def->category = OptionCategory::perimeter;
-    def->tooltip = L("If the (external) angle at the seam is higher than this value, then no notch will be set. If the angle is too high, there isn't enough room for the notch.");
+    def->tooltip = L("If the (external) angle at the seam is higher than this value, then no notch will be set. If the angle is too high, there isn't enough room for the notch."
+                    "\nCan't be lower than 180° or it filters everything. At 360, it allows everything.");
     def->sidetext = L("°");
-    def->min = 0;
+    def->min = 180;
     def->max = 360;
     def->mode = comExpert | comSuSi;
     def->set_default_value(new ConfigOptionFloat(250));