SFML/include/SFML/Graphics/CircleShape.hpp

////////////////////////////////////////////////////////////
//
// SFML - Simple and Fast Multimedia Library
// Copyright (C) 2007-2024 Laurent Gomila (laurent@sfml-dev.org)
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented;
//    you must not claim that you wrote the original software.
//    If you use this software in a product, an acknowledgment
//    in the product documentation would be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such,
//    and must not be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
////////////////////////////////////////////////////////////

#pragma once

////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/Graphics/Export.hpp>

#include <SFML/Graphics/Shape.hpp>

#include <SFML/System/Vector2.hpp>

#include <cstddef>


namespace sf
{
////////////////////////////////////////////////////////////
/// \brief Specialized shape representing a circle
///
////////////////////////////////////////////////////////////
class SFML_GRAPHICS_API CircleShape : public Shape
{
public:
    ////////////////////////////////////////////////////////////
    /// \brief Default constructor
    ///
    /// \param radius     Radius of the circle
    /// \param pointCount Number of points composing the circle
    ///
    ////////////////////////////////////////////////////////////
    explicit CircleShape(float radius = 0, std::size_t pointCount = 30);

    ////////////////////////////////////////////////////////////
    /// \brief Set the radius of the circle
    ///
    /// \param radius New radius of the circle
    ///
    /// \see `getRadius`
    ///
    ////////////////////////////////////////////////////////////
    void setRadius(float radius);

    ////////////////////////////////////////////////////////////
    /// \brief Get the radius of the circle
    ///
    /// \return Radius of the circle
    ///
    /// \see `setRadius`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] float getRadius() const;

    ////////////////////////////////////////////////////////////
    /// \brief Set the number of points of the circle
    ///
    /// \param count New number of points of the circle
    ///
    /// \see `getPointCount`
    ///
    ////////////////////////////////////////////////////////////
    void setPointCount(std::size_t count);

    ////////////////////////////////////////////////////////////
    /// \brief Get the number of points of the circle
    ///
    /// \return Number of points of the circle
    ///
    /// \see `setPointCount`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] std::size_t getPointCount() const override;

    ////////////////////////////////////////////////////////////
    /// \brief Get a point of the circle
    ///
    /// The returned point is in local coordinates, that is,
    /// the shape's transforms (position, rotation, scale) are
    /// not taken into account.
    /// The result is undefined if \a `index` is out of the valid range.
    ///
    /// \param index Index of the point to get, in range [0 .. getPointCount() - 1]
    ///
    /// \return index-th point of the shape
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] Vector2f getPoint(std::size_t index) const override;

    ////////////////////////////////////////////////////////////
    /// \brief Get the geometric center of the circle
    ///
    /// The returned point is in local coordinates, that is,
    /// the shape's transforms (position, rotation, scale) are
    /// not taken into account.
    ///
    /// \return The geometric center of the shape
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] Vector2f getGeometricCenter() const override;

private:
    ////////////////////////////////////////////////////////////
    // Member data
    ////////////////////////////////////////////////////////////
    float       m_radius;     //!< Radius of the circle
    std::size_t m_pointCount; //!< Number of points composing the circle
};

} // namespace sf


////////////////////////////////////////////////////////////
/// \class sf::CircleShape
/// \ingroup graphics
///
/// This class inherits all the functions of `sf::Transformable`
/// (position, rotation, scale, bounds, ...) as well as the
/// functions of `sf::Shape` (outline, color, texture, ...).
///
/// Usage example:
/// \code
/// sf::CircleShape circle;
/// circle.setRadius(150);
/// circle.setOutlineColor(sf::Color::Red);
/// circle.setOutlineThickness(5);
/// circle.setPosition({10, 20});
/// ...
/// 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`
///
////////////////////////////////////////////////////////////