BackendFontSDLttf.hpp

 
//
// TGUI - Texus' Graphical User Interface
// Copyright (C) 2012-2022 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.
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//
 
 
#ifndef TGUI_BACKEND_FONT_SDL_TTF_HPP
#define TGUI_BACKEND_FONT_SDL_TTF_HPP
 
#include <TGUI/Backend/Font/BackendFont.hpp>
#include <TGUI/extlibs/IncludeSDL.hpp>
#include <SDL_ttf.h>
#include <unordered_map>
 
 
namespace tgui
{
 class BackendFontSDLttf : public BackendFont
 {
 public:
 
 ~BackendFontSDLttf() override;
 
 
 bool loadFromMemory(std::unique_ptr<std::uint8_t[]> data, std::size_t sizeInBytes) override;
 using BackendFont::loadFromMemory;
 
 
 bool hasGlyph(char32_t codePoint) const override;
 
 
 FontGlyph getGlyph(char32_t codePoint, unsigned int characterSize, bool bold, float outlineThickness = 0) override;
 
 
 float getKerning(char32_t first, char32_t second, unsigned int characterSize, bool bold) override;
 
 
 float getLineSpacing(unsigned int characterSize) override;
 
 
 float getFontHeight(unsigned int characterSize) override;
 
 
 float getAscent(unsigned int characterSize) override;
 
 
 float getDescent(unsigned int characterSize) override;
 
 
 float getUnderlinePosition(unsigned int characterSize) override;
 
 
 float getUnderlineThickness(unsigned int characterSize) override;
 
 
 std::shared_ptr<BackendTexture> getTexture(unsigned int characterSize, unsigned int& textureVersion) override;
 
 
 Vector2u getTextureSize(unsigned int characterSize) override;
 
 
 void setSmooth(bool smooth) override;
 
 
 void setFontScale(float scale) override;
 
 
 TTF_Font* getInternalFont(unsigned int characterSize);
 
 
 private:
 
 // Finds the location and thickness of the underline, for the getUnderlinePosition and getUnderlineThickness functions
 std::pair<int, int> getUnderlineInfo(unsigned int characterSize);
 
 
 // Reserves space in the texture to place the glyph
 UIntRect findAvailableGlyphRect(unsigned int width, unsigned int height);
 
 
 private:
 
 struct Row
 {
 Row(unsigned int rowTop, unsigned int rowHeight) : width(0), top(rowTop), height(rowHeight) {}
 
 unsigned int width; 
 unsigned int top; 
 unsigned int height; 
 };
 
 std::unique_ptr<std::uint8_t[]> m_fileContents;
 std::size_t m_fileSize = 0;
 
 // TTF_Font needs a character size, so we store one font per character size
 std::unordered_map<unsigned int, TTF_Font*> m_fonts;
 std::unordered_map<unsigned int, bool> m_lastBoldFlag;
 std::unordered_map<unsigned int, int> m_lastOutlineThickness;
 
 std::unordered_map<unsigned int, std::pair<int, int>> m_cachedUnderlineInfo; // character size -> (underline vertical offset, underline thickness)
 
 std::unordered_map<std::uint64_t, FontGlyph> m_glyphs;
 unsigned int m_nextRow = 3; 
 std::vector<Row> m_rows;
 
 std::unique_ptr<std::uint8_t[]> m_pixels;
 std::shared_ptr<BackendTexture> m_texture;
 unsigned int m_textureSize = 0;
 unsigned int m_textureVersion = 0;
 };
}
 
 
#endif // TGUI_BACKEND_FONT_SDL_TTF_HPP