mgl_alignment.h

[詳解]

// SPDX-License-Identifier: Zlib
/* ------------------------------------------------------------------------- */
/* ------------------------------------------------------------------------- */
 
#ifndef INCGUARD_MGL_ALIGNMENT_H_1625900468
#define INCGUARD_MGL_ALIGNMENT_H_1625900468
 
#include <mgl/math/mgl_vector2.h>
#include <mgl/math/mgl_rectangle.h>
 
namespace MGL
{
struct Alignment
{
    enum class Horizontal : uint8_t
    {
        Left,       
        Center,     
        Right       
    };
 
    enum class Vertical : uint8_t
    {
        Top,        
        Middle,     
        Bottom      
    };
 
    Horizontal horizontal;  
    Vertical vertical;      
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    constexpr Alignment() noexcept
        : horizontal(Horizontal::Left)
        , vertical(Vertical::Top)
    {
    }
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    constexpr Alignment(Horizontal inHorizontal, Vertical inVertical) noexcept
        : horizontal(inHorizontal)
        , vertical(inVertical)
    {
    }
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    constexpr Alignment(Vertical inVertical, Horizontal inHorizontal) noexcept
        : horizontal(inHorizontal)
        , vertical(inVertical)
    {
    }
 
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    [[nodiscard]] constexpr MGL::Vector2 AdjustPosition(const MGL::Vector2 &baseSize, const MGL::Vector2 &position) const noexcept
    {
        MGL::Vector2 adjustedPosition(position);
 
        switch (horizontal)
        {
            case Horizontal::Left:
                break;
 
            case Horizontal::Center:
                adjustedPosition.x += baseSize.x * 0.5f;
                break;
 
            case Horizontal::Right:
                adjustedPosition.x += baseSize.x;
                break;
        }
 
        switch (vertical)
        {
            case Vertical::Top:
                break;
 
            case Vertical::Middle:
                adjustedPosition.y += baseSize.y * 0.5f;
                break;
 
            case Vertical::Bottom:
                adjustedPosition.y += baseSize.y;
                break;
        }
 
        return adjustedPosition;
    }
    
    /* ------------------------------------------------------------------------- */
    /* ------------------------------------------------------------------------- */
    [[nodiscard]] constexpr MGL::Vector2 AdjustRectangle(const MGL::Rectangle &rectangle) const noexcept
    {
        MGL::Vector2 adjustedPosition(rectangle.GetPosition());
        
        switch (horizontal)
        {
            case Horizontal::Left:
                break;
                
            case Horizontal::Center:
                adjustedPosition.x -= rectangle.width * 0.5f;
                break;
                
            case Horizontal::Right:
                adjustedPosition.x -= rectangle.width;
                break;
        }
        
        switch (vertical)
        {
            case Vertical::Top:
                break;
                
            case Vertical::Middle:
                adjustedPosition.y -= rectangle.height * 0.5f;
                break;
                
            case Vertical::Bottom:
                adjustedPosition.y -= rectangle.height;
                break;
        }
        
        return adjustedPosition;
    }
};
 
constexpr auto kAlignmentTopLeft         = Alignment(Alignment::Vertical::Top,     Alignment::Horizontal::Left);      
constexpr auto kAlignmentTopCenter       = Alignment(Alignment::Vertical::Top,     Alignment::Horizontal::Center);    
constexpr auto kAlignmentTopRight        = Alignment(Alignment::Vertical::Top,     Alignment::Horizontal::Right);     
constexpr auto kAlignmentMiddleLeft      = Alignment(Alignment::Vertical::Middle,  Alignment::Horizontal::Left);      
constexpr auto kAlignmentMiddleCenter    = Alignment(Alignment::Vertical::Middle,  Alignment::Horizontal::Center);    
constexpr auto kAlignmentMiddleRight     = Alignment(Alignment::Vertical::Middle,  Alignment::Horizontal::Right);     
constexpr auto kAlignmentBottomLeft      = Alignment(Alignment::Vertical::Bottom,  Alignment::Horizontal::Left);      
constexpr auto kAlignmentBottomCenter    = Alignment(Alignment::Vertical::Bottom,  Alignment::Horizontal::Center);    
constexpr auto kAlignmentBottomRight     = Alignment(Alignment::Vertical::Bottom,  Alignment::Horizontal::Right);     
 
}   // namespace MGL
 
#endif  // INCGUARD_MGL_ALIGNMENT_H_1625900468
 
// vim: et ts=4 sw=4 sts=4