Added SetPointsCount in sf::CircleShape

include/SFML/Graphics/CircleShape.hpp

@@ -45,9 +45,10 @@ public :
     /// \brief Default constructor
     ///
     /// \param radius      Radius of the circle
+    /// \param pointsCount Number of points composing the circle
     ///
     ////////////////////////////////////////////////////////////
-    explicit CircleShape(float radius = 0);
+    explicit CircleShape(float radius = 0, unsigned int pointsCount = 30);
 
     ////////////////////////////////////////////////////////////
     /// \brief Set the radius of the circle
@@ -69,11 +70,23 @@ public :
     ////////////////////////////////////////////////////////////
     float GetRadius() const;
 
+    ////////////////////////////////////////////////////////////
+    /// \brief Set the number of points of the circle
+    ///
+    /// \param count New number of points of the circle
+    ///
+    /// \see GetPointsCount
+    ///
+    ////////////////////////////////////////////////////////////
+    void SetPointsCount(unsigned int count);
+
     ////////////////////////////////////////////////////////////
     /// \brief Get the number of points of the shape
     ///
     /// \return Number of points of the shape
     ///
+    /// \see SetPointsCount
+    ///
     ////////////////////////////////////////////////////////////
     virtual unsigned int GetPointsCount() const;
 
@@ -93,6 +106,7 @@ private :
     // Member data
     ////////////////////////////////////////////////////////////
     float        myRadius;      ///< Radius of the circle
+    unsigned int myPointsCount; ///< Number of points composing the circle
 };
 
 } // namespace sf
@@ -120,6 +134,15 @@ private :
 /// window.Draw(circle);
 /// \endcode
 ///
+/// Since the graphics card can't draw perfect circles, we have to
+/// fake them with multiple triangles connected to each other. The
+/// "points count" property of sf::CircleShape defines how many of these
+/// triangles to use, and therefore defines the quality of the circle.
+///
+/// The number of points can also be used for another purpose; with
+/// small numbers you can create any regular polygon shape:
+/// equilateral triangle, square, pentagon, hexagon, ...
+///
 /// \see sf::Shape, sf::RectangleShape, sf::ConvexShape
 ///
 ////////////////////////////////////////////////////////////

src/SFML/Graphics/CircleShape.cpp

@@ -32,9 +32,11 @@
 namespace sf
 {
 ////////////////////////////////////////////////////////////
-CircleShape::CircleShape(float radius) 
+CircleShape::CircleShape(float radius, unsigned int pointsCount) :
+myRadius     (radius),
+myPointsCount(pointsCount)
 {
-    SetRadius(radius);
+    Update();
 }
 
 
@@ -53,17 +55,26 @@ float CircleShape::GetRadius() const
 }
 
 
+////////////////////////////////////////////////////////////
+void CircleShape::SetPointsCount(unsigned int count)
+{
+    myPointsCount = count;
+    Update();
+}
+
 ////////////////////////////////////////////////////////////
 unsigned int CircleShape::GetPointsCount() const
 {
-    return 30;
+    return myPointsCount;
 }
 
 
 ////////////////////////////////////////////////////////////
 Vector2f CircleShape::GetPoint(unsigned int index) const
 {
-    float angle = index * 2 * 3.141592654f / GetPointsCount();
+    static const float pi = 3.141592654f;
+
+    float angle = index * 2 * pi / myPointsCount - pi / 2;
     float x = std::cos(angle) * myRadius;
     float y = std::sin(angle) * myRadius;