BackendFontSFML.hpp

//
// TGUI - Texus' Graphical User Interface
// Copyright (C) 2012-2025 Bruno Van de Velde (vdv_b@tgui.eu)
//
// 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.
//
 
#ifndef TGUI_BACKEND_FONT_SFML_HPP
#define TGUI_BACKEND_FONT_SFML_HPP
 
#include <TGUI/Backend/Font/BackendFont.hpp>
 
#include <SFML/Graphics/Font.hpp>
 
#include <unordered_set>
#include <memory>
#include <map>

 
namespace tgui
{
    class TGUI_API BackendFontSFML : public BackendFont
    {
    public:

        bool loadFromMemory(std::unique_ptr<std::uint8_t[]> data, std::size_t sizeInBytes) override;
        using BackendFont::loadFromMemory;

        TGUI_NODISCARD bool hasGlyph(char32_t codePoint) const override;

        TGUI_NODISCARD FontGlyph getGlyph(char32_t codePoint, unsigned int characterSize, bool bold, float outlineThickness = 0) override;

        TGUI_NODISCARD float getKerning(char32_t first, char32_t second, unsigned int characterSize, bool bold) override;

        TGUI_NODISCARD float getLineSpacing(unsigned int characterSize) override;

        TGUI_NODISCARD float getFontHeight(unsigned int characterSize) override;

        TGUI_NODISCARD float getAscent(unsigned int characterSize) override;

        TGUI_NODISCARD float getDescent(unsigned int characterSize) override;

        TGUI_NODISCARD float getUnderlinePosition(unsigned int characterSize) override;

        TGUI_NODISCARD float getUnderlineThickness(unsigned int characterSize) override;

        TGUI_NODISCARD std::shared_ptr<BackendTexture> getTexture(unsigned int characterSize, unsigned int& textureVersion) override;

        TGUI_NODISCARD Vector2u getTextureSize(unsigned int characterSize) override;

        void setSmooth(bool smooth) override;

        void setFontScale(float scale) override;

        TGUI_NODISCARD sf::Font* getInternalFont();

    protected:
 
        std::unique_ptr<sf::Font> m_font;
        std::unique_ptr<std::uint8_t[]> m_fileContents;
 
        std::unordered_set<std::uint64_t> m_loadedGlyphKeys;
 
        // We keep one texture per character size. Other font backends don't do this, but this is to prevent existing code
        // from breaking since sf::Font does the same.
        std::map<unsigned int, std::shared_ptr<BackendTexture>> m_textures;
        std::map<unsigned int, unsigned int> m_textureVersions;
 
        // We use a single version that is unique across all text sizes. Otherwise switching from size by changing the font scale
        // can result in the same version being accidentally returned and the text not realizing that the texture changed.
        unsigned int m_lastTextureVersion = 0;
    };
}

 
#endif // TGUI_BACKEND_FONT_SFML_HPP