Added optimized methods for point and polyline rotation.

Existing methods for rotation were optimized by calculating the sin/cos values once only.
Added an operator- for points.

4 files changed, 54 insertions, 4 deletions

diff --git a/xs/src/libslic3r/MultiPoint.cpp b/xs/src/libslic3r/MultiPoint.cpp
index ff2771cff..1e1895634 100644
--- a/xs/src/libslic3r/MultiPoint.cpp
+++ b/xs/src/libslic3r/MultiPoint.cpp
@@ -31,6 +31,20 @@ MultiPoint::translate(const Point &vector)
 }
 
 void
+MultiPoint::rotate(double angle)
+{
+    double s     = sin(angle);
+    double c     = cos(angle);
+    for (Points::iterator it = points.begin(); it != points.end(); ++it) {
+        (*it).rotate(angle);
+	    double cur_x = (double)it->x;
+	    double cur_y = (double)it->y;
+	    it->x = (coord_t)round(c * cur_x - s * cur_y);
+	    it->y = (coord_t)round(c * cur_y + s * cur_x);
+    }
+}
+
+void
 MultiPoint::rotate(double angle, const Point &center)
 {
     for (Points::iterator it = points.begin(); it != points.end(); ++it) {
diff --git a/xs/src/libslic3r/MultiPoint.hpp b/xs/src/libslic3r/MultiPoint.hpp
index 18d67a9e4..0f31fd318 100644
--- a/xs/src/libslic3r/MultiPoint.hpp
+++ b/xs/src/libslic3r/MultiPoint.hpp
@@ -22,6 +22,7 @@ class MultiPoint
     void scale(double factor);
     void translate(double x, double y);
     void translate(const Point &vector);
+    void rotate(double angle);
     void rotate(double angle, const Point &center);
     void reverse();
     Point first_point() const;
diff --git a/xs/src/libslic3r/Point.cpp b/xs/src/libslic3r/Point.cpp
index dc9d510c6..8dad1c5d7 100644
--- a/xs/src/libslic3r/Point.cpp
+++ b/xs/src/libslic3r/Point.cpp
@@ -47,12 +47,25 @@ Point::translate(const Vector &vector)
 }
 
 void
+Point::rotate(double angle)
+{
+    double cur_x = (double)this->x;
+    double cur_y = (double)this->y;
+    double s     = sin(angle);
+    double c     = cos(angle);
+    this->x = (coord_t)round(c * cur_x - s * cur_y);
+    this->y = (coord_t)round(c * cur_y + s * cur_x);
+}
+
+void
 Point::rotate(double angle, const Point &center)
 {
     double cur_x = (double)this->x;
     double cur_y = (double)this->y;
-    this->x = (coord_t)round( (double)center.x + cos(angle) * (cur_x - (double)center.x) - sin(angle) * (cur_y - (double)center.y) );
-    this->y = (coord_t)round( (double)center.y + cos(angle) * (cur_y - (double)center.y) + sin(angle) * (cur_x - (double)center.x) );
+    double s     = sin(angle);
+    double c     = cos(angle);
+    this->x = (coord_t)round( (double)center.x + c * (cur_x - (double)center.x) - s * (cur_y - (double)center.y) );
+    this->y = (coord_t)round( (double)center.y + c * (cur_y - (double)center.y) + s * (cur_x - (double)center.x) );
 }
 
 bool
@@ -294,6 +307,12 @@ operator+(const Point& point1, const Point& point2)
 }
 
 Point
+operator-(const Point& point1, const Point& point2)
+{
+    return Point(point1.x - point2.x, point1.y - point2.y);
+}
+
+Point
 operator*(double scalar, const Point& point2)
 {
     return Point(scalar * point2.x, scalar * point2.y);
@@ -334,12 +353,25 @@ Pointf::translate(const Vectorf &vector)
 }
 
 void
+Pointf::rotate(double angle)
+{
+    double cur_x = this->x;
+    double cur_y = this->y;
+    double s     = sin(angle);
+    double c     = cos(angle);
+    this->x = c * cur_x - s * cur_y;
+    this->y = c * cur_y + s * cur_x;
+}
+
+void
 Pointf::rotate(double angle, const Pointf &center)
 {
     double cur_x = this->x;
     double cur_y = this->y;
-    this->x = center.x + cos(angle) * (cur_x - center.x) - sin(angle) * (cur_y - center.y);
-    this->y = center.y + cos(angle) * (cur_y - center.y) + sin(angle) * (cur_x - center.x);
+    double s     = sin(angle);
+    double c     = cos(angle);
+    this->x = center.x + c * (cur_x - center.x) - s * (cur_y - center.y);
+    this->y = center.y + c * (cur_y - center.y) + s * (cur_x - center.x);
 }
 
 Pointf
diff --git a/xs/src/libslic3r/Point.hpp b/xs/src/libslic3r/Point.hpp
index dbd1219b9..14c5cf70f 100644
--- a/xs/src/libslic3r/Point.hpp
+++ b/xs/src/libslic3r/Point.hpp
@@ -41,6 +41,7 @@ class Point
     void scale(double factor);
     void translate(double x, double y);
     void translate(const Vector &vector);
+    void rotate(double angle);
     void rotate(double angle, const Point &center);
     bool coincides_with(const Point &point) const;
     bool coincides_with_epsilon(const Point &point) const;
@@ -63,6 +64,7 @@ class Point
 };
 
 Point operator+(const Point& point1, const Point& point2);
+Point operator-(const Point& point1, const Point& point2);
 Point operator*(double scalar, const Point& point2);
 
 class Point3 : public Point
@@ -90,6 +92,7 @@ class Pointf
     void scale(double factor);
     void translate(double x, double y);
     void translate(const Vectorf &vector);
+    void rotate(double angle);
     void rotate(double angle, const Pointf &center);
     Pointf negative() const;
     Vectorf vector_to(const Pointf &point) const;