BackendText.hpp

//
// TGUI - Texus' Graphical User Interface
// Copyright (C) 2012-2026 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_TEXT_HPP
#define TGUI_BACKEND_TEXT_HPP
 
#include <TGUI/Backend/Font/BackendFont.hpp>
#include <TGUI/Backend/Renderer/BackendTexture.hpp>
 
#include <TGUI/Text.hpp>

 
namespace tgui
{
    class TGUI_API BackendText
    {
    public:
        using TextVertexData = std::vector<std::pair<std::shared_ptr<BackendTexture>, std::shared_ptr<std::vector<Vertex>>>>;
 
        // Don't allow copying or moving, because we don't expect derived classes to handle it correctly
        BackendText(const BackendText&) = delete;
        BackendText(BackendText&&) = delete;
        BackendText& operator=(const BackendText&) = delete;
        BackendText& operator=(BackendText&&) = delete;

        BackendText() = default;

        virtual ~BackendText() = default;

        [[nodiscard]] virtual Vector2f getSize();

        virtual void setString(const String& string);

        [[nodiscard]] const String& getString() const;

        virtual void setCharacterSize(unsigned int characterSize);

        [[nodiscard]] unsigned int getCharacterSize() const;

        virtual void setFillColor(const Color& color);

        [[nodiscard]] Color getFillColor() const;

        virtual void setOutlineColor(const Color& color);

        [[nodiscard]] Color getOutlineColor() const;

        virtual void setOutlineThickness(float thickness);

        [[nodiscard]] float getOutlineThickness() const;

        virtual void setStyle(TextStyles style);

        [[nodiscard]] TextStyles getStyle() const;

        virtual void setFont(const std::shared_ptr<BackendFont>& font);

        [[nodiscard]] std::shared_ptr<BackendFont> getFont() const;

        [[nodiscard]] virtual Vector2f findCharacterPos(std::size_t index) const;

        [[nodiscard]] TextVertexData getVertexData(bool includeOutline = true, bool includeText = true);

 
    protected:
        // Recreates all vertices if required
        void updateVertices();

        // Helper function used by updateVertices to add vertices for a glyph
        static void addGlyphQuad(std::vector<Vertex>& vertices,
                                 Vector2f position,
                                 const Vertex::Color& color,
                                 const FontGlyph& glyph,
                                 float fontScale,
                                 float italicShear);

        // Helper function used by updateVertices to add vertices for a line
        static void addLine(std::vector<Vertex>& vertices,
                            float lineLength,
                            float lineTop,
                            const Vertex::Color& color,
                            float offset,
                            float thickness,
                            float outlineThickness,
                            float fontScale);

 
    protected:
        std::shared_ptr<BackendFont> m_font;
        unsigned int m_lastFontTextureVersion = 0;
 
        String m_string;
        unsigned int m_characterSize = getGlobalTextSize();
        Color m_fillColor;
        Color m_outlineColor;
        float m_outlineThickness = 0;
        TextStyles m_style = TextStyle::Regular;
 
        Vector2f m_size;
        std::shared_ptr<std::vector<Vertex>> m_vertices;
        std::shared_ptr<std::vector<Vertex>> m_outlineVertices;
        bool m_verticesNeedUpdate = true;
    };
} // namespace tgui
 
#endif // TGUI_BACKEND_TEXT_HPP