Font_Cache FontFamily_Impl::get_font(const FontDescription &desc, float pixel_ratio)
{
// Find cached version
for (auto &cache : font_cache)
{
if (cache.pixel_ratio != pixel_ratio)
continue;
if (desc.get_style() != cache.engine->get_desc().get_style())
continue;
if (desc.get_weight() != cache.engine->get_desc().get_weight())
continue;
if (desc.get_subpixel() != cache.engine->get_desc().get_subpixel())
continue;
if (desc.get_anti_alias() != cache.engine->get_desc().get_anti_alias())
continue;
if (cache.engine->is_automatic_recreation_allowed())
{
if (desc.get_height() != cache.engine->get_desc().get_height())
continue;
}
return cache;
}
return Font_Cache();
}
std::string FontConfig::match_font(const std::string &typeface_name, const FontDescription &desc) const
{
FcPattern * fc_pattern = nullptr;
FcPattern * fc_match = nullptr;
try
{
int weight = static_cast<int>(desc.get_weight());
// Build font matching pattern.
fc_pattern = FcPatternBuild(nullptr,
FC_FAMILY, FcTypeString, typeface_name.c_str(),
FC_PIXEL_SIZE, FcTypeDouble, (double)std::abs(desc.get_height()),
FC_WEIGHT, FcTypeInteger, (weight > 0) ? (int)(weight * (FC_WEIGHT_HEAVY / 900.0)) : FC_WEIGHT_NORMAL,
FC_SLANT, FcTypeInteger, (desc.get_style() == clan::FontStyle::italic) ? FC_SLANT_ITALIC : ((desc.get_style() == clan::FontStyle::oblique) ? FC_SLANT_OBLIQUE : FC_SLANT_ROMAN),
FC_SPACING, FcTypeInteger, FC_PROPORTIONAL,
(char*) nullptr
);
if (!fc_pattern)
{
throw Exception("CL_FontConfig: Building FontConfig pattern failed.");
}
// Execute any needed param substitutions required by the system config.
if (FcTrue != FcConfigSubstitute(fc_config, fc_pattern, FcMatchPattern))
{
throw Exception("CL_FontConfig: Font config substitutions failed.");
}
// Supply default values for underspecified font patterns. Never fails.
FcDefaultSubstitute(fc_pattern);
// Find best match for pattern and extract filename.
FcResult match_result; // Doesn't appear to be actually updated.
fc_match = FcFontMatch(fc_config, fc_pattern, &match_result);
FcChar8 * fc_font_file_path = nullptr;
if (FcResultMatch != FcPatternGetString(fc_match, FC_FILE, 0, &fc_font_file_path))
{
throw Exception("CL_FontConfig: Could not resolve font pattern to a font file.");
}
// Release resources and return results.
std::string cl_font_file_path((char*)fc_font_file_path);
FcPatternDestroy(fc_match);
FcPatternDestroy(fc_pattern);
return cl_font_file_path;
}
catch (...)
{
// If any exceptions thrown, ensure fontconfig resources are released.
if (fc_match) FcPatternDestroy(fc_match);
if (fc_pattern) FcPatternDestroy(fc_pattern);
throw;
}
}
Font_Cache FontFamily_Impl::copy_font(const FontDescription &desc, float pixel_ratio)
{
// Find existing typeface, to obtain shared data that we can copy
FontFamily_Definition font_definition;
bool found = false;
// Find find an exact match using style and weight
for (auto &definitions : font_definitions)
{
if (desc.get_style() != definitions.desc.get_style())
continue;
if (desc.get_weight() != definitions.desc.get_weight())
continue;
font_definition = definitions;
found = true;
break;
}
// Else find the first font
if (!found)
{
if (!font_definitions.empty())
{
font_definition = font_definitions[0];
found = true;
}
}
if (!found)
{
// Could not find a cached version of the font to use as reference
font_face_load(desc, family_name, pixel_ratio);
}
else
{
if (!font_definition.font_databuffer.is_null())
{
// Cached font is allocated via a font databuffer
font_face_load(desc, font_definition.font_databuffer, pixel_ratio);
}
else
{
// Cached font has allocated the typeface_name
font_face_load(desc, font_definition.typeface_name, pixel_ratio);
}
}
return font_cache.back();
}
