Text.hpp

#ifndef MYGL_TEXT
#define MYGL_TEXT
 
#include "../mygl_export.h"
 
#include "Font.hpp"
#include "Rectangle.hpp"
#include <iterator>
#include <string_view>
#include <utfcpp/utf8.h>
 
namespace my
{
    namespace util
    {
        template<typename StringType>
        inline std::string toUtf8(const StringType& text) {
            std::basic_string_view view{std::begin(text), std::end(text)};
 
            using CharType = typename decltype(view)::value_type;
 
            if constexpr (sizeof(CharType) == 1) {
                return view;
            } else if constexpr (sizeof(CharType) == 2) {
                std::string result;
                result.reserve(2 * view.size());
                utf8::utf16to8(view.begin(), view.end(), std::back_inserter(result));
                return result;
            } else if constexpr (sizeof(CharType) == 4) {
                std::string result;
                result.reserve(4 * view.size());
                utf8::utf32to8(view.begin(), view.end(), std::back_inserter(result));
                return result;
            } else {
                // Some compilers need a templated expression or they always trigger
                // the assertion when using `static_assert(false, ...)`
                static_assert(sizeof(CharType) == 0, "Unknown character encoding");
            }
        }
    } // namespace util
 
    class Text : public Rectangle
    {
    private:
        static my::ShaderProgram textShader;
        static my::Font defaultFont;
 
        std::string m_text;
        my::Font& m_font;
        unsigned int m_size;
 
        void init();
 
        void setTexture(const my::Texture& texture) override;
 
    public:
        MYGL_EXPORT Text();
 
        MYGL_EXPORT Text(const std::string& text, my::Font& font, unsigned int size = 30u);
 
        MYGL_EXPORT ~Text() override;
 
        MYGL_EXPORT void setContent(const std::string& text);
 
        MYGL_EXPORT const std::string& getContent() const;
 
        MYGL_EXPORT void setFont(my::Font& font);
 
        MYGL_EXPORT void setFontSize(unsigned int size);
    };
 
} // namespace my
 
#endif // MYGL_TEXT