From decdaa82d3db9619b45d3c59d5106526cf65d57d Mon Sep 17 00:00:00 2001
From: enricoturri1966 <enricoturri@seznam.cz>
Date: Fri, 22 Oct 2021 13:51:33 +0200
Subject: [PATCH] Modified implementation of Line::parallel_to(const Line&
 line) and Line::perpendicular_to(const Line& line)

---
 src/libslic3r/Line.cpp | 14 ++++++++++++++
 src/libslic3r/Line.hpp |  4 ++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/libslic3r/Line.cpp b/src/libslic3r/Line.cpp
index 1a96b8b1f..78ca2b9af 100644
--- a/src/libslic3r/Line.cpp
+++ b/src/libslic3r/Line.cpp
@@ -63,11 +63,25 @@ bool Line::parallel_to(double angle) const
     return Slic3r::Geometry::directions_parallel(this->direction(), angle);
 }
 
+bool Line::parallel_to(const Line& line) const
+{
+    const Vec2d v1 = (this->b - this->a).cast<double>();
+    const Vec2d v2 = (line.b - line.a).cast<double>();
+    return std::fabs(cross2(v1, v2)) < EPSILON;
+}
+
 #if ENABLE_OUT_OF_BED_DETECTION_IMPROVEMENTS
 bool Line::perpendicular_to(double angle) const
 {
     return Slic3r::Geometry::directions_perpendicular(this->direction(), angle);
 }
+
+bool Line::perpendicular_to(const Line& line) const
+{
+    const Vec2d v1 = (this->b - this->a).cast<double>();
+    const Vec2d v2 = (line.b - line.a).cast<double>();
+    return std::fabs(v1.dot(v2)) < EPSILON;
+}
 #endif // ENABLE_OUT_OF_BED_DETECTION_IMPROVEMENTS
 
 bool Line::intersection(const Line &l2, Point *intersection) const
diff --git a/src/libslic3r/Line.hpp b/src/libslic3r/Line.hpp
index 4a33c7c9c..a4dcd827c 100644
--- a/src/libslic3r/Line.hpp
+++ b/src/libslic3r/Line.hpp
@@ -104,10 +104,10 @@ public:
     double distance_to(const Point &point) const { return distance_to(point, this->a, this->b); }
     double perp_distance_to(const Point &point) const;
     bool   parallel_to(double angle) const;
-    bool   parallel_to(const Line &line) const { return this->parallel_to(line.direction()); }
+    bool   parallel_to(const Line& line) const;
 #if ENABLE_OUT_OF_BED_DETECTION_IMPROVEMENTS
     bool   perpendicular_to(double angle) const;
-    bool   perpendicular_to(const Line& line) const { return this->perpendicular_to(line.direction()); }
+    bool   perpendicular_to(const Line& line) const;
 #endif // ENABLE_OUT_OF_BED_DETECTION_IMPROVEMENTS
     double atan2_() const { return atan2(this->b(1) - this->a(1), this->b(0) - this->a(0)); }
     double orientation() const;