src/client/fontengine.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2010-2014 sapier <sapier at gmx dot net>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "fontengine.h"
  21 #include <cmath>
  22 #include "client/renderingengine.h"
  23 #include "config.h"
  24 #include "porting.h"
  25 #include "filesys.h"
  26 #include "gettext.h"
  27 #include "irrlicht_changes/CGUITTFont.h"
  28
  29 /** maximum size distance for getting a "similar" font size */
  30 #define MAX_FONT_SIZE_OFFSET 10
  31
  32 /** reference to access font engine, has to be initialized by main */
  33 FontEngine* g_fontengine = NULL;
  34
  35 /** callback to be used on change of font size setting */
  36 static void font_setting_changed(const std::string &name, void *userdata)
  37 {
  38         g_fontengine->readSettings();
  39 }
  40
  41 /******************************************************************************/
  42 FontEngine::FontEngine(gui::IGUIEnvironment* env) :
  43         m_env(env)
  44 {
  45         for (u32 &i : m_default_size) {
  46                 i = FONT_SIZE_UNSPECIFIED;
  47         }
  48
  49         assert(g_settings != NULL); // pre-condition
  50         assert(m_env != NULL); // pre-condition
  51         assert(m_env->getSkin() != NULL); // pre-condition
  52
  53         readSettings();
  54
  55         const char *settings[] = {
  56                 "font_size", "font_bold", "font_italic", "font_size_divisible_by",
  57                 "mono_font_size", "mono_font_size_divisible_by",
  58                 "font_shadow", "font_shadow_alpha",
  59                 "font_path", "font_path_bold", "font_path_italic", "font_path_bold_italic",
  60                 "mono_font_path", "mono_font_path_bold", "mono_font_path_italic",
  61                 "mono_font_path_bold_italic",
  62                 "fallback_font_path",
  63                 "screen_dpi", "gui_scaling",
  64         };
  65
  66         for (auto name : settings)
  67                 g_settings->registerChangedCallback(name, font_setting_changed, NULL);
  68 }
  69
  70 /******************************************************************************/
  71 FontEngine::~FontEngine()
  72 {
  73         cleanCache();
  74 }
  75
  76 /******************************************************************************/
  77 void FontEngine::cleanCache()
  78 {
  79         RecursiveMutexAutoLock l(m_font_mutex);
  80
  81         for (auto &font_cache_it : m_font_cache) {
  82
  83                 for (auto &font_it : font_cache_it) {
  84                         font_it.second->drop();
  85                         font_it.second = nullptr;
  86                 }
  87                 font_cache_it.clear();
  88         }
  89 }
  90
  91 /******************************************************************************/
  92 irr::gui::IGUIFont *FontEngine::getFont(FontSpec spec)
  93 {
  94         return getFont(spec, false);
  95 }
  96
  97 irr::gui::IGUIFont *FontEngine::getFont(FontSpec spec, bool may_fail)
  98 {
  99         if (spec.mode == FM_Unspecified) {
 100                 spec.mode = m_currentMode;
 101         } else if (spec.mode == _FM_Fallback) {
 102                 // Fallback font doesn't support these
 103                 spec.bold = false;
 104                 spec.italic = false;
 105         }
 106
 107         // Fallback to default size
 108         if (spec.size == FONT_SIZE_UNSPECIFIED)
 109                 spec.size = m_default_size[spec.mode];
 110
 111         RecursiveMutexAutoLock l(m_font_mutex);
 112
 113         const auto &cache = m_font_cache[spec.getHash()];
 114         auto it = cache.find(spec.size);
 115         if (it != cache.end())
 116                 return it->second;
 117
 118         // Font does not yet exist
 119         gui::IGUIFont *font = initFont(spec);
 120
 121         if (!font && !may_fail) {
 122                 errorstream << "Minetest cannot continue without a valid font. "
 123                         "Please correct the 'font_path' setting or install the font "
 124                         "file in the proper location." << std::endl;
 125                 abort();
 126         }
 127
 128         m_font_cache[spec.getHash()][spec.size] = font;
 129
 130         return font;
 131 }
 132
 133 /******************************************************************************/
 134 unsigned int FontEngine::getTextHeight(const FontSpec &spec)
 135 {
 136         gui::IGUIFont *font = getFont(spec);
 137
 138         return font->getDimension(L"Some unimportant example String").Height;
 139 }
 140
 141 /******************************************************************************/
 142 unsigned int FontEngine::getTextWidth(const std::wstring &text, const FontSpec &spec)
 143 {
 144         gui::IGUIFont *font = getFont(spec);
 145
 146         return font->getDimension(text.c_str()).Width;
 147 }
 148
 149 /** get line height for a specific font (including empty room between lines) */
 150 unsigned int FontEngine::getLineHeight(const FontSpec &spec)
 151 {
 152         gui::IGUIFont *font = getFont(spec);
 153
 154         return font->getDimension(L"Some unimportant example String").Height
 155                         + font->getKerningHeight();
 156 }
 157
 158 /******************************************************************************/
 159 unsigned int FontEngine::getDefaultFontSize()
 160 {
 161         return m_default_size[m_currentMode];
 162 }
 163
 164 unsigned int FontEngine::getFontSize(FontMode mode)
 165 {
 166         if (mode == FM_Unspecified)
 167                 return m_default_size[FM_Standard];
 168
 169         return m_default_size[mode];
 170 }
 171
 172 /******************************************************************************/
 173 void FontEngine::readSettings()
 174 {
 175         m_default_size[FM_Standard]  = g_settings->getU16("font_size");
 176         m_default_size[_FM_Fallback] = g_settings->getU16("font_size");
 177         m_default_size[FM_Mono]      = g_settings->getU16("mono_font_size");
 178
 179         m_default_bold = g_settings->getBool("font_bold");
 180         m_default_italic = g_settings->getBool("font_italic");
 181
 182         cleanCache();
 183         updateFontCache();
 184         updateSkin();
 185 }
 186
 187 /******************************************************************************/
 188 void FontEngine::updateSkin()
 189 {
 190         gui::IGUIFont *font = getFont();
 191         assert(font);
 192
 193         m_env->getSkin()->setFont(font);
 194 }
 195
 196 /******************************************************************************/
 197 void FontEngine::updateFontCache()
 198 {
 199         /* the only font to be initialized is default one,
 200          * all others are re-initialized on demand */
 201         getFont(FONT_SIZE_UNSPECIFIED, FM_Unspecified);
 202 }
 203
 204 /******************************************************************************/
 205 gui::IGUIFont *FontEngine::initFont(const FontSpec &spec)
 206 {
 207         assert(spec.mode != FM_Unspecified);
 208         assert(spec.size != FONT_SIZE_UNSPECIFIED);
 209
 210         std::string setting_prefix = "";
 211         if (spec.mode == FM_Mono)
 212                 setting_prefix = "mono_";
 213
 214         std::string setting_suffix = "";
 215         if (spec.bold)
 216                 setting_suffix.append("_bold");
 217         if (spec.italic)
 218                 setting_suffix.append("_italic");
 219
 220         u32 size = std::max<u32>(spec.size * RenderingEngine::getDisplayDensity() *
 221                         g_settings->getFloat("gui_scaling"), 1);
 222
 223         // Constrain the font size to a certain multiple, if necessary
 224         u16 divisible_by = g_settings->getU16(setting_prefix + "font_size_divisible_by");
 225         if (divisible_by > 1) {
 226                 size = std::max<u32>(
 227                                 std::round((double)size / divisible_by) * divisible_by, divisible_by);
 228         }
 229
 230         sanity_check(size != 0);
 231
 232         u16 font_shadow       = 0;
 233         u16 font_shadow_alpha = 0;
 234         g_settings->getU16NoEx(setting_prefix + "font_shadow", font_shadow);
 235         g_settings->getU16NoEx(setting_prefix + "font_shadow_alpha",
 236                         font_shadow_alpha);
 237
 238         std::string path_setting;
 239         if (spec.mode == _FM_Fallback)
 240                 path_setting = "fallback_font_path";
 241         else
 242                 path_setting = setting_prefix + "font_path" + setting_suffix;
 243
 244         std::string fallback_settings[] = {
 245                 g_settings->get(path_setting),
 246                 Settings::getLayer(SL_DEFAULTS)->get(path_setting)
 247         };
 248
 249         for (const std::string &font_path : fallback_settings) {
 250                 gui::CGUITTFont *font = gui::CGUITTFont::createTTFont(m_env,
 251                                 font_path.c_str(), size, true, true, font_shadow,
 252                                 font_shadow_alpha);
 253
 254                 if (!font) {
 255                         errorstream << "FontEngine: Cannot load '" << font_path <<
 256                                 "'. Trying to fall back to another path." << std::endl;
 257                         continue;
 258                 }
 259
 260                 if (spec.mode != _FM_Fallback) {
 261                         FontSpec spec2(spec);
 262                         spec2.mode = _FM_Fallback;
 263                         font->setFallback(getFont(spec2, true));
 264                 }
 265                 return font;
 266         }
 267         return nullptr;
 268 }