New get_extents(const std::vector<Points> &pts),

refactored Lian Barsky line clipping

src/libslic3r/Geometry.hpp

@@ -213,16 +213,7 @@ inline bool liang_barsky_line_clipping_interval(
     double t0 = 0.0;
     double t1 = 1.0;
     // Traverse through left, right, bottom, top edges.
-    for (int edge = 0; edge < 4; ++ edge)
-    {
-        double p, q;
-        switch (edge) {
-        case 0:  p = - v.x();    q = - bbox.min.x() + x0.x();   break;
-        case 1:  p =   v.x();    q =   bbox.max.x() - x0.x();   break;
-        case 2:  p = - v.y();    q = - bbox.min.y() + x0.y();   break;
-        default: p =   v.y();    q =   bbox.max.y() - x0.y();   break;
-        }
-        
+    auto clip_side = [&x0, &v, &bbox, &t0, &t1](double p, double q) -> bool {
         if (p == 0) {
             if (q < 0)
                 // Line parallel to the bounding box edge is fully outside of the bounding box.
@@ -247,11 +238,19 @@ inline bool liang_barsky_line_clipping_interval(
                     t1 = r;
             }
         }
-    }
+        return true;
+    };
+
+    if (clip_side(- v.x(), - bbox.min.x() + x0.x()) &&
+        clip_side(  v.x(),   bbox.max.x() - x0.x()) &&
+        clip_side(- v.y(), - bbox.min.y() + x0.y()) &&
+        clip_side(  v.y(),   bbox.max.y() - x0.y())) {
         out_interval.first = t0;
         out_interval.second = t1;
         return true;
     }
+    return false;
+}
 
 template<typename T>
 inline bool liang_barsky_line_clipping(

src/libslic3r/Point.cpp

@@ -176,6 +176,19 @@ Point Point::projection_onto(const Line &line) const
     return ((line.a - *this).cast<double>().squaredNorm() < (line.b - *this).cast<double>().squaredNorm()) ? line.a : line.b;
 }
 
+BoundingBox get_extents(const Points &pts)
+{ 
+    return BoundingBox(pts);
+}
+
+BoundingBox get_extents(const std::vector<Points> &pts)
+{
+    BoundingBox bbox;
+    for (const Points &p : pts)
+        bbox.merge(get_extents(p));
+    return bbox;
+}
+
 std::ostream& operator<<(std::ostream &stm, const Vec2d &pointf)
 {
     return stm << pointf(0) << "," << pointf(1);

src/libslic3r/Point.hpp

@@ -13,6 +13,7 @@
 
 namespace Slic3r {
 
+class BoundingBox;
 class Line;
 class MultiPoint;
 class Point;
@@ -178,6 +179,9 @@ inline Point lerp(const Point &a, const Point &b, double t)
     return ((1. - t) * a.cast<double>() + t * b.cast<double>()).cast<coord_t>();
 }
 
+extern BoundingBox get_extents(const Points &pts);
+extern BoundingBox get_extents(const std::vector<Points> &pts);
+
 namespace int128 {
     // Exact orientation predicate,
     // returns +1: CCW, 0: collinear, -1: CW.

src/libslic3r/Polygon.cpp

@@ -298,11 +298,6 @@ void Polygon::densify(float min_length, std::vector<float>* lengths_ptr)
     assert(points.size() == lengths.size() - 1);
 }
 
-BoundingBox get_extents(const Points &points)
-{ 
-	return BoundingBox(points);
-}
-
 BoundingBox get_extents(const Polygon &poly) 
 { 
     return poly.bounding_box();

src/libslic3r/Polygon.hpp

@@ -74,7 +74,6 @@ public:
 inline bool operator==(const Polygon &lhs, const Polygon &rhs) { return lhs.points == rhs.points; }
 inline bool operator!=(const Polygon &lhs, const Polygon &rhs) { return lhs.points != rhs.points; }
 
-extern BoundingBox get_extents(const Points &points);
 extern BoundingBox get_extents(const Polygon &poly);
 extern BoundingBox get_extents(const Polygons &polygons);
 extern BoundingBox get_extents_rotated(const Polygon &poly, double angle);