Fixed issue with the detection of the correct triangle for endpoints

xs/src/libslic3r/Geometry.cpp

@@ -343,14 +343,28 @@ linint(double value, double oldmin, double oldmax, double newmin, double newmax)
     return (value - oldmin) * (newmax - newmin) / (oldmax - oldmin) + newmin;
 }
 
+bool
+point_in_bounding_box(Pointf pt, Pointf v1, Pointf v2, Pointf v3, double epsilon)
+{
+    //check if point is in x range
+    if (pt.x < std::min({v1.x, v2.x, v3.x}) - epsilon || pt.x > std::max({v1.x, v2.x, v3.x}) + epsilon) {
+        return false;
+    }
+    //check if point is in y range
+    if (pt.y < std::min({v1.y, v2.y, v3.y}) - epsilon || pt.y > std::max({v1.y, v2.y, v3.y}) + epsilon) {
+        return false;
+    }
+    return true;
+}
+
 float
 sign(Pointf p1, Pointf p2, Pointf p3)
 {
     return (p1.x - p3.x) * (p2.y - p3.y) - (p2.x - p3.x) * (p1.y - p3.y);
 }
 
 bool
-Point_in_triangle(Pointf pt, Pointf v1, Pointf v2, Pointf v3)
+Point_in_triangle_side(Pointf pt, Pointf v1, Pointf v2, Pointf v3)
 {
     //Check if point is right of every edge
     if (sign(pt, v1, v2) <= 0.0f) return false;
@@ -360,6 +374,68 @@ Point_in_triangle(Pointf pt, Pointf v1, Pointf v2, Pointf v3)
     return true;
 }
 
+// bool
+// Point_in_triangle_barycentric(Pointf pt, Pointf v1, Pointf v2, Pointf v3)
+// {
+//     double denom = ((v2.y - v3.y)*(v1.x - v3.x) + (v3.x - v2.x)*(v1.y - v3.y));
+//     double a = ((v2.y - v3.y)*(pt.x - v3.x) + (v3.x - v2.x)*(pt.y - v3.y)) / denom;
+//     double b = ((v3.y - v1.y)*(pt.x - v3.x) + (v1.x - v3.x)*(pt.y - v3.y)) / denom;
+//     double c = 1 - a - b;
+
+//     return (0 <= a && a <= 1 && 0 <= b && b <= 1 && 0 <= c && c <= 1);
+// }
+
+double
+distanceSquarePointToSegment(Pointf pt, Pointf v1, Pointf v2)
+{
+    double p1_p2_squareLength = (v2.x - v1.x)*(v2.x - v1.x) + (v2.y - v1.y)*(v2.y - v1.y);
+    double dotProduct = ((pt.x - v1.x)*(v2.x - v1.x) + (pt.y - v1.y)*(v2.y - v1.y)) / p1_p2_squareLength;
+    if ( dotProduct < 0 )
+    {
+        return (pt.x - v1.x)*(pt.x - v1.x) + (pt.y - v1.y)*(pt.y - v1.y);
+    }
+    else if ( dotProduct <= 1 )
+    {
+        double p_p1_squareLength = (v1.x - pt.x)*(v1.x - pt.x) + (v1.y - pt.y)*(v1.y - pt.y);
+        return p_p1_squareLength - dotProduct * dotProduct * p1_p2_squareLength;
+    }
+    else
+    {
+        return (pt.x - v2.x)*(pt.x - v2.x) + (pt.y - v2.y)*(pt.y - v2.y);
+    }
+}
+
+bool
+Point_in_triangle(Pointf pt, Pointf v1, Pointf v2, Pointf v3, double epsilon)
+{
+    const double EPSILON_SQUARE = epsilon*epsilon;
+
+    //taken from http://totologic.blogspot.com/2014/01/accurate-point-in-triangle-test.html
+    //check if pt is in bounding box
+    if (!point_in_bounding_box(pt,v1,v2,v3,epsilon)){
+        return false;
+    }
+
+    //check if point is in triangle
+    if (Point_in_triangle_side(pt,v1,v2,v3)){
+        //if yes, we trust the test
+        return true;
+    } else {
+        //if no, we dont trust the test and check further
+        if (distanceSquarePointToSegment(pt,v1,v2) <= EPSILON_SQUARE){
+            return true;
+        }
+        if (distanceSquarePointToSegment(pt,v2,v3) <= EPSILON_SQUARE){
+            return true;
+        }
+        if (distanceSquarePointToSegment(pt,v3,v1) <= EPSILON_SQUARE){
+            return true;
+        }
+        //if everything fails, the point is not in the triangle
+        return false;
+    }
+}
+
 //https://graphics.stanford.edu/~mdfisher/Code/Engine/Plane.cpp.html
 void
 Project_point_on_plane(Pointf3 v1,  Pointf3 n, Point &pt)

xs/src/libslic3r/Geometry.hpp

@@ -26,7 +26,7 @@ double rad2deg_dir(double angle);
 double deg2rad(double angle);
 
 double linint(double value, double oldmin, double oldmax, double newmin, double newmax);
-bool Point_in_triangle(Pointf pt, Pointf v1, Pointf v2, Pointf v3);
+bool Point_in_triangle(Pointf pt, Pointf v1, Pointf v2, Pointf v3, double epsilon);
 void Project_point_on_plane(Pointf3 v1,  Pointf3 n, Point &pt);
 Point* Line_intersection(Point p1, Point p2, Point p3, Point p4);
 float triangle_surface(Point p1, Point p2, Point p3);

xs/src/libslic3r/LayerRegion.cpp

@@ -368,27 +368,20 @@ LayerRegion::project_nonplanar_path(ExtrusionPath *path)
         for (auto& surface : this->nonplanar_surfaces) {
             float distance_to_top = surface.stats.max.z - this->layer()->print_z;
             for(auto& facet : surface.mesh) {
-                //skip if point is outside of the bounding box of the triangle
-                if (unscale(point.x) < std::min({facet.second.vertex[0].x, facet.second.vertex[1].x, facet.second.vertex[2].x}) ||
-                    unscale(point.x) > std::max({facet.second.vertex[0].x, facet.second.vertex[1].x, facet.second.vertex[2].x}) ||
-                    unscale(point.y) < std::min({facet.second.vertex[0].y, facet.second.vertex[1].y, facet.second.vertex[2].y}) ||
-                    unscale(point.y) > std::max({facet.second.vertex[0].y, facet.second.vertex[1].y, facet.second.vertex[2].y}))
-                {
-                    continue;
-                }
                 //check if point is inside of Triangle
                 if (Slic3r::Geometry::Point_in_triangle(
                     Pointf(unscale(point.x),unscale(point.y)),
                     Pointf(facet.second.vertex[0].x, facet.second.vertex[0].y),
                     Pointf(facet.second.vertex[1].x, facet.second.vertex[1].y),
-                    Pointf(facet.second.vertex[2].x, facet.second.vertex[2].y)))
+                    Pointf(facet.second.vertex[2].x, facet.second.vertex[2].y),
+                    0.1))
                 {
                     Slic3r::Geometry::Project_point_on_plane(Pointf3(facet.second.vertex[0].x,facet.second.vertex[0].y,facet.second.vertex[0].z),
                                                              Pointf3(facet.second.normal.x,facet.second.normal.y,facet.second.normal.z),
                                                              point);
                     //Shift down when on lower layer
                     point.z = point.z - scale_(distance_to_top);
-                    //break;
+                    break;
                 }
             }
         }