////////////////////////////////////////////////////////////
//
// 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/Color.hpp>
#include <SFML/Graphics/Drawable.hpp>
#include <SFML/Graphics/PrimitiveType.hpp>
#include <SFML/Graphics/Rect.hpp>
#include <SFML/Graphics/RenderStates.hpp>
#include <SFML/Graphics/Transformable.hpp>
#include <SFML/Graphics/VertexArray.hpp>

#include <SFML/System/Vector2.hpp>

#include <cstddef>


namespace sf
{
class Texture;
class RenderTarget;

////////////////////////////////////////////////////////////
/// \brief Base class for textured shapes with outline
///
////////////////////////////////////////////////////////////
class SFML_GRAPHICS_API Shape : public Drawable, public Transformable
{
public:
    ////////////////////////////////////////////////////////////
    /// \brief Change the source texture of the shape
    ///
    /// The `texture` argument refers to a texture that must
    /// exist as long as the shape uses it. Indeed, the shape
    /// doesn't store its own copy of the texture, but rather keeps
    /// a pointer to the one that you passed to this function.
    /// If the source texture is destroyed and the shape tries to
    /// use it, the behavior is undefined.
    /// `texture` can be a null pointer to disable texturing.
    /// If `resetRect` is `true`, the `TextureRect` property of
    /// the shape is automatically adjusted to the size of the new
    /// texture. If it is `false`, the texture rect is left unchanged.
    ///
    /// \param texture   New texture
    /// \param resetRect Should the texture rect be reset to the size of the new texture?
    ///
    /// \see `getTexture`, `setTextureRect`
    ///
    ////////////////////////////////////////////////////////////
    void setTexture(const Texture* texture, bool resetRect = false);

    ////////////////////////////////////////////////////////////
    /// \brief Set the sub-rectangle of the texture that the shape will display
    ///
    /// The texture rect is useful when you don't want to display
    /// the whole texture, but rather a part of it.
    /// By default, the texture rect covers the entire texture.
    ///
    /// \param rect Rectangle defining the region of the texture to display
    ///
    /// \see `getTextureRect`, `setTexture`
    ///
    ////////////////////////////////////////////////////////////
    void setTextureRect(const IntRect& rect);

    ////////////////////////////////////////////////////////////
    /// \brief Set the fill color of the shape
    ///
    /// This color is modulated (multiplied) with the shape's
    /// texture if any. It can be used to colorize the shape,
    /// or change its global opacity.
    /// You can use `sf::Color::Transparent` to make the inside of
    /// the shape transparent, and have the outline alone.
    /// By default, the shape's fill color is opaque white.
    ///
    /// \param color New color of the shape
    ///
    /// \see `getFillColor`, `setOutlineColor`
    ///
    ////////////////////////////////////////////////////////////
    void setFillColor(Color color);

    ////////////////////////////////////////////////////////////
    /// \brief Set the outline color of the shape
    ///
    /// By default, the shape's outline color is opaque white.
    ///
    /// \param color New outline color of the shape
    ///
    /// \see `getOutlineColor`, `setFillColor`
    ///
    ////////////////////////////////////////////////////////////
    void setOutlineColor(Color color);

    ////////////////////////////////////////////////////////////
    /// \brief Set the thickness of the shape's outline
    ///
    /// Note that negative values are allowed (so that the outline
    /// expands towards the center of the shape), and using zero
    /// disables the outline.
    /// By default, the outline thickness is 0.
    ///
    /// \param thickness New outline thickness
    ///
    /// \see `getOutlineThickness`
    ///
    ////////////////////////////////////////////////////////////
    void setOutlineThickness(float thickness);

    ////////////////////////////////////////////////////////////
    /// \brief Get the source texture of the shape
    ///
    /// If the shape has no source texture, a `nullptr` is returned.
    /// The returned pointer is const, which means that you can't
    /// modify the texture when you retrieve it with this function.
    ///
    /// \return Pointer to the shape's texture
    ///
    /// \see `setTexture`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] const Texture* getTexture() const;

    ////////////////////////////////////////////////////////////
    /// \brief Get the sub-rectangle of the texture displayed by the shape
    ///
    /// \return Texture rectangle of the shape
    ///
    /// \see `setTextureRect`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] const IntRect& getTextureRect() const;

    ////////////////////////////////////////////////////////////
    /// \brief Get the fill color of the shape
    ///
    /// \return Fill color of the shape
    ///
    /// \see `setFillColor`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] Color getFillColor() const;

    ////////////////////////////////////////////////////////////
    /// \brief Get the outline color of the shape
    ///
    /// \return Outline color of the shape
    ///
    /// \see `setOutlineColor`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] Color getOutlineColor() const;

    ////////////////////////////////////////////////////////////
    /// \brief Get the outline thickness of the shape
    ///
    /// \return Outline thickness of the shape
    ///
    /// \see `setOutlineThickness`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] float getOutlineThickness() const;

    ////////////////////////////////////////////////////////////
    /// \brief Get the total number of points of the shape
    ///
    /// \return Number of points of the shape
    ///
    /// \see `getPoint`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] virtual std::size_t getPointCount() const = 0;

    ////////////////////////////////////////////////////////////
    /// \brief Get a point of the shape
    ///
    /// 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 `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
    ///
    /// \see `getPointCount`
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] virtual Vector2f getPoint(std::size_t index) const = 0;

    ////////////////////////////////////////////////////////////
    /// \brief Get the geometric center of the shape
    ///
    /// 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]] virtual Vector2f getGeometricCenter() const;

    ////////////////////////////////////////////////////////////
    /// \brief Get the local bounding rectangle of the entity
    ///
    /// The returned rectangle is in local coordinates, which means
    /// that it ignores the transformations (translation, rotation,
    /// scale, ...) that are applied to the entity.
    /// In other words, this function returns the bounds of the
    /// entity in the entity's coordinate system.
    ///
    /// \return Local bounding rectangle of the entity
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] FloatRect getLocalBounds() const;

    ////////////////////////////////////////////////////////////
    /// \brief Get the global (non-minimal) bounding rectangle of the entity
    ///
    /// The returned rectangle is in global coordinates, which means
    /// that it takes into account the transformations (translation,
    /// rotation, scale, ...) that are applied to the entity.
    /// In other words, this function returns the bounds of the
    /// shape in the global 2D world's coordinate system.
    ///
    /// This function does not necessarily return the _minimal_
    /// bounding rectangle. It merely ensures that the returned
    /// rectangle covers all the vertices (but possibly more).
    /// This allows for a fast approximation of the bounds as a
    /// first check; you may want to use more precise checks
    /// on top of that.
    ///
    /// \return Global bounding rectangle of the entity
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] FloatRect getGlobalBounds() const;

protected:
    ////////////////////////////////////////////////////////////
    /// \brief Recompute the internal geometry of the shape
    ///
    /// This function must be called by the derived class every time
    /// the shape's points change (i.e. the result of either
    /// getPointCount or getPoint is different).
    ///
    ////////////////////////////////////////////////////////////
    void update();

private:
    ////////////////////////////////////////////////////////////
    /// \brief Draw the shape to a render target
    ///
    /// \param target Render target to draw to
    /// \param states Current render states
    ///
    ////////////////////////////////////////////////////////////
    void draw(RenderTarget& target, RenderStates states) const override;

    ////////////////////////////////////////////////////////////
    /// \brief Update the fill vertices' color
    ///
    ////////////////////////////////////////////////////////////
    void updateFillColors();

    ////////////////////////////////////////////////////////////
    /// \brief Update the fill vertices' texture coordinates
    ///
    ////////////////////////////////////////////////////////////
    void updateTexCoords();

    ////////////////////////////////////////////////////////////
    /// \brief Update the outline vertices' position
    ///
    ////////////////////////////////////////////////////////////
    void updateOutline();

    ////////////////////////////////////////////////////////////
    /// \brief Update the outline vertices' color
    ///
    ////////////////////////////////////////////////////////////
    void updateOutlineColors();

    ////////////////////////////////////////////////////////////
    // Member data
    ////////////////////////////////////////////////////////////
    const Texture* m_texture{};                  //!< Texture of the shape
    IntRect        m_textureRect;                //!< Rectangle defining the area of the source texture to display
    Color          m_fillColor{Color::White};    //!< Fill color
    Color          m_outlineColor{Color::White}; //!< Outline color
    float          m_outlineThickness{};         //!< Thickness of the shape's outline
    VertexArray    m_vertices{PrimitiveType::TriangleFan};          //!< Vertex array containing the fill geometry
    VertexArray    m_outlineVertices{PrimitiveType::TriangleStrip}; //!< Vertex array containing the outline geometry
    FloatRect      m_insideBounds;                                  //!< Bounding rectangle of the inside (fill)
    FloatRect      m_bounds; //!< Bounding rectangle of the whole shape (outline + fill)
};

} // namespace sf


////////////////////////////////////////////////////////////
/// \class sf::Shape
/// \ingroup graphics
///
/// `sf::Shape` is a drawable class that allows to define and
/// display a custom convex shape on a render target.
/// It's only an abstract base, it needs to be specialized for
/// concrete types of shapes (circle, rectangle, convex polygon,
/// star, ...).
///
/// In addition to the attributes provided by the specialized
/// shape classes, a shape always has the following attributes:
/// \li a texture
/// \li a texture rectangle
/// \li a fill color
/// \li an outline color
/// \li an outline thickness
///
/// Each feature is optional, and can be disabled easily:
/// \li the texture can be null
/// \li the fill/outline colors can be `sf::Color::Transparent`
/// \li the outline thickness can be zero
///
/// You can write your own derived shape class, there are only
/// two virtual functions to override:
/// \li getPointCount must return the number of points of the shape
/// \li getPoint must return the points of the shape
///
/// \see `sf::RectangleShape`, `sf::CircleShape`, `sf::ConvexShape`, `sf::Transformable`
///
////////////////////////////////////////////////////////////
