Files
ladybird/Libraries/LibGfx/FontCascadeList.cpp

122 lines
3.9 KiB
C++

/*
* Copyright (c) 2023, Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibGfx/FontCascadeList.h>
namespace Gfx {
void FontCascadeList::add(NonnullRefPtr<Font const> font)
{
m_fonts.append({ move(font), {} });
}
void FontCascadeList::add(NonnullRefPtr<Font const> font, Vector<UnicodeRange> unicode_ranges)
{
if (unicode_ranges.is_empty()) {
m_fonts.append({ move(font), {} });
return;
}
u32 lowest_code_point = 0xFFFFFFFF;
u32 highest_code_point = 0;
for (auto& range : unicode_ranges) {
lowest_code_point = min(lowest_code_point, range.min_code_point());
highest_code_point = max(highest_code_point, range.max_code_point());
}
m_fonts.append({ move(font),
Entry::RangeData {
{ lowest_code_point, highest_code_point },
move(unicode_ranges),
} });
}
void FontCascadeList::add_pending_face(Vector<UnicodeRange> unicode_ranges, Function<void()> start_load)
{
if (unicode_ranges.is_empty())
return;
u32 lowest_code_point = 0xFFFFFFFF;
u32 highest_code_point = 0;
for (auto const& range : unicode_ranges) {
lowest_code_point = min(lowest_code_point, range.min_code_point());
highest_code_point = max(highest_code_point, range.max_code_point());
}
m_pending_faces.append(adopt_ref(*new PendingFace(
UnicodeRange { lowest_code_point, highest_code_point },
move(unicode_ranges),
move(start_load))));
}
void FontCascadeList::extend(FontCascadeList const& other)
{
m_fonts.extend(other.m_fonts);
m_pending_faces.extend(other.m_pending_faces);
}
Gfx::Font const& FontCascadeList::font_for_code_point(u32 code_point) const
{
// Walk pending entries first: if this codepoint falls in an unloaded face's
// unicode-range we kick off the fetch and drop the entry — a fallback font that
// happens to cover the codepoint shouldn't prevent the real face from loading.
// FontComputer::clear_computed_font_cache() rebuilds the cascade once the fetch
// completes, so later shapes pick up the loaded face. Run before the ASCII cache
// lookup so a previously-cached codepoint still triggers a newly-added face.
m_pending_faces.remove_all_matching([code_point](auto const& pending) {
if (!pending->covers(code_point))
return false;
pending->start_load();
return true;
});
if (code_point < m_ascii_cache.size()) {
if (auto const* cached = m_ascii_cache[code_point])
return *cached;
}
auto cache_and_return = [&](Font const& font) -> Font const& {
if (code_point < m_ascii_cache.size())
m_ascii_cache[code_point] = &font;
return font;
};
for (auto const& entry : m_fonts) {
if (entry.range_data.has_value()) {
if (!entry.range_data->enclosing_range.contains(code_point))
continue;
for (auto const& range : entry.range_data->unicode_ranges) {
if (range.contains(code_point) && entry.font->contains_glyph(code_point))
return cache_and_return(*entry.font);
}
} else if (entry.font->contains_glyph(code_point)) {
return cache_and_return(*entry.font);
}
}
if (m_system_font_fallback_callback) {
if (auto fallback = m_system_font_fallback_callback(code_point, first())) {
m_fonts.append({ fallback.release_nonnull(), {} });
return cache_and_return(*m_fonts.last().font);
}
}
return cache_and_return(*m_last_resort_font);
}
bool FontCascadeList::equals(FontCascadeList const& other) const
{
if (m_fonts.size() != other.m_fonts.size())
return false;
for (size_t i = 0; i < m_fonts.size(); ++i) {
if (m_fonts[i].font != other.m_fonts[i].font)
return false;
}
return true;
}
}