TGUI  0.10-dev
BackendFontFreeType.hpp
1
2//
3// TGUI - Texus' Graphical User Interface
4// Copyright (C) 2012-2021 Bruno Van de Velde (vdv_b@tgui.eu)
5//
6// This software is provided 'as-is', without any express or implied warranty.
7// In no event will the authors be held liable for any damages arising from the use of this software.
8//
9// Permission is granted to anyone to use this software for any purpose,
10// including commercial applications, and to alter it and redistribute it freely,
11// subject to the following restrictions:
12//
13// 1. The origin of this software must not be misrepresented;
14// you must not claim that you wrote the original software.
15// If you use this software in a product, an acknowledgment
16// in the product documentation would be appreciated but is not required.
17//
18// 2. Altered source versions must be plainly marked as such,
19// and must not be misrepresented as being the original software.
20//
21// 3. This notice may not be removed or altered from any source distribution.
22//
24
25
26#ifndef TGUI_BACKEND_FONT_FREETYPE_HPP
27#define TGUI_BACKEND_FONT_FREETYPE_HPP
28
29#include <TGUI/Backend/Font/BackendFont.hpp>
30#include <unordered_map>
31
33
34typedef struct FT_LibraryRec_* FT_Library;
35typedef struct FT_FaceRec_* FT_Face;
36typedef struct FT_StrokerRec_* FT_Stroker;
37
39
40namespace tgui
41{
46 {
47 public:
48
53
54
63 virtual bool loadFromMemory(std::unique_ptr<std::uint8_t[]> data, std::size_t sizeInBytes) override;
65
66
74 bool hasGlyph(char32_t codePoint) const override;
75
76
90 virtual FontGlyph getGlyph(char32_t codePoint, unsigned int characterSize, bool bold, float outlineThickness = 0) override;
91
92
107 virtual float getKerning(char32_t first, char32_t second, unsigned int characterSize, bool bold) override;
108
109
119 virtual float getLineSpacing(unsigned int characterSize) override;
120
121
131 float getUnderlinePosition(unsigned int characterSize) override;
132
133
143 float getUnderlineThickness(unsigned int characterSize) override;
144
145
153 std::shared_ptr<BackendTexture> getTexture(unsigned int characterSize) override;
154
155
165 void setSmooth(bool smooth) override;
166
167
169 protected:
170
171 struct Glyph
172 {
173 float advance = 0;
174 float lsbDelta = 0;
175 float rsbDelta = 0;
178 };
179
180
182 // Loads a glyph with freetype
184 Glyph loadGlyph(char32_t codePoint, unsigned int characterSize, bool bold, float outlineThickness);
185
186
188 // Returns a cached glyph or calls loadGlyph to load it when this is the first time the glyph is requested
190 Glyph getInternalGlyph(char32_t codePoint, unsigned int characterSize, bool bold, float outlineThickness);
191
192
194 // Reserves space in the texture to place the glyph
196 IntRect findAvailableGlyphRect(unsigned int width, unsigned int height);
197
198
200 // Sets the character size on which the freetype operations are performed
202 bool setCurrentSize(unsigned int characterSize);
203
204
206 // Destroys freetype resources
208 void cleanup();
209
210
212 protected:
213
214 struct Row
215 {
216 Row(unsigned int rowTop, unsigned int rowHeight) : width(0), top(rowTop), height(rowHeight) {}
217
218 unsigned int width;
219 unsigned int top;
220 unsigned int height;
221 };
222
223 FT_Library m_library = nullptr; // Handle to the freetype library
224 FT_Face m_face = nullptr; // Contains the font (typeface and style)
225 FT_Stroker m_stroker = nullptr; // Used for rendering outlines
226
227 std::unordered_map<unsigned int, float> m_cachedLineSpacing;
228
229 std::unordered_map<std::uint64_t, Glyph> m_glyphs;
230 unsigned int m_nextRow = 3;
231 std::vector<Row> m_rows;
232
233 std::unique_ptr<std::uint8_t[]> m_fileContents;
234 std::unique_ptr<std::uint8_t[]> m_pixels;
235 std::shared_ptr<BackendTexture> m_texture;
236 unsigned int m_textureSize = 0;
237 bool m_textureUpToDate = false;
238 };
239
241}
242
244
245#endif // TGUI_BACKEND_FONT_FREETYPE_HPP
Font implementations that uses FreeType directly to load glyphs.
Definition: BackendFontFreeType.hpp:46
virtual FontGlyph getGlyph(char32_t codePoint, unsigned int characterSize, bool bold, float outlineThickness=0) override
Retrieve a glyph of the font.
virtual float getLineSpacing(unsigned int characterSize) override
Returns the line spacing.
float getUnderlineThickness(unsigned int characterSize) override
Get the thickness of the underline.
virtual float getKerning(char32_t first, char32_t second, unsigned int characterSize, bool bold) override
Returns the kerning offset of two glyphs.
float getUnderlinePosition(unsigned int characterSize) override
Get the position of the underline.
~BackendFontFreetype()
Destructor that cleans up the FreeType resources.
unsigned int m_nextRow
Y position of the next new row in the texture (first 2 rows contain pixels for underlining)
Definition: BackendFontFreeType.hpp:230
std::shared_ptr< BackendTexture > getTexture(unsigned int characterSize) override
Returns the texture that is used to store glyphs of the given character size.
void setSmooth(bool smooth) override
Enable or disable the smooth filter.
virtual bool loadFromMemory(std::unique_ptr< std::uint8_t[]> data, std::size_t sizeInBytes) override
Loads a font from memory.
bool hasGlyph(char32_t codePoint) const override
Returns whether a font contains a certain glyph.
Base class for font implementations that depend on the backend.
Definition: BackendFont.hpp:43
virtual bool loadFromMemory(std::unique_ptr< std::uint8_t[]> data, std::size_t sizeInBytes)=0
Loads a font from memory.
Namespace that contains all TGUI functions and classes.
Definition: AbsoluteOrRelativeValue.hpp:36
Definition: BackendFontFreeType.hpp:172
IntRect textureRect
Texture coordinates of the glyph inside the font's texture.
Definition: BackendFontFreeType.hpp:177
float rsbDelta
Right offset after forced autohint. Internally used by getKerning()
Definition: BackendFontFreeType.hpp:175
float lsbDelta
Left offset after forced autohint. Internally used by getKerning()
Definition: BackendFontFreeType.hpp:174
float advance
Offset to move horizontally to the next character.
Definition: BackendFontFreeType.hpp:173
FloatRect bounds
Bounding rectangle of the glyph, in coordinates relative to the baseline.
Definition: BackendFontFreeType.hpp:176
Definition: BackendFontFreeType.hpp:215
unsigned int height
Height of the row.
Definition: BackendFontFreeType.hpp:220
unsigned int width
Current width of the row.
Definition: BackendFontFreeType.hpp:218
unsigned int top
Y position of the row into the texture.
Definition: BackendFontFreeType.hpp:219
Information about a glyph in the font.
Definition: Font.hpp:47