ladybird/Userland/Libraries/LibGfx/BitmapFont.cpp
Andreas Kling 0f6dd8c62b LibGfx: Make Gfx::FontMetrics include the advance of '0' instead of 'M'
CSS actually wants the advance of the ASCII '0' character for its "ch"
units, so let's include that instead of the arbitrarily chosen 'M'.
2022-03-30 00:57:15 +02:00

385 lines
14 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "BitmapFont.h"
#include "Emoji.h"
#include <AK/BuiltinWrappers.h>
#include <AK/Utf32View.h>
#include <AK/Utf8View.h>
#include <LibCore/FileStream.h>
#include <LibGfx/FontDatabase.h>
#include <LibGfx/FontStyleMapping.h>
#include <string.h>
namespace Gfx {
struct [[gnu::packed]] FontFileHeader {
char magic[4];
u8 glyph_width;
u8 glyph_height;
u16 range_mask_size;
u8 is_variable_width;
u8 glyph_spacing;
u8 baseline;
u8 mean_line;
u8 presentation_size;
u16 weight;
u8 slope;
char name[32];
char family[32];
};
static_assert(AssertSize<FontFileHeader, 80>());
static constexpr size_t s_max_glyph_count = 0x110000;
static constexpr size_t s_max_range_mask_size = s_max_glyph_count / (256 * 8);
NonnullRefPtr<Font> BitmapFont::clone() const
{
auto* new_range_mask = static_cast<u8*>(malloc(m_range_mask_size));
memcpy(new_range_mask, m_range_mask, m_range_mask_size);
size_t bytes_per_glyph = sizeof(u32) * glyph_height();
auto* new_rows = static_cast<u8*>(kmalloc_array(m_glyph_count, bytes_per_glyph));
memcpy(new_rows, m_rows, bytes_per_glyph * m_glyph_count);
auto* new_widths = static_cast<u8*>(malloc(m_glyph_count));
memcpy(new_widths, m_glyph_widths, m_glyph_count);
return adopt_ref(*new BitmapFont(m_name, m_family, new_rows, new_widths, m_fixed_width, m_glyph_width, m_glyph_height, m_glyph_spacing, m_range_mask_size, new_range_mask, m_baseline, m_mean_line, m_presentation_size, m_weight, m_slope, true));
}
NonnullRefPtr<BitmapFont> BitmapFont::create(u8 glyph_height, u8 glyph_width, bool fixed, size_t glyph_count)
{
glyph_count += 256 - (glyph_count % 256);
glyph_count = min(glyph_count, s_max_glyph_count);
size_t glyphs_per_range = 8 * 256;
u16 range_mask_size = ceil_div(glyph_count, glyphs_per_range);
auto* new_range_mask = static_cast<u8*>(calloc(range_mask_size, 1));
for (size_t i = 0; i < glyph_count; i += 256) {
new_range_mask[i / 256 / 8] |= 1 << (i / 256 % 8);
}
size_t bytes_per_glyph = sizeof(u32) * glyph_height;
auto* new_rows = static_cast<u8*>(calloc(glyph_count, bytes_per_glyph));
auto* new_widths = static_cast<u8*>(calloc(glyph_count, 1));
return adopt_ref(*new BitmapFont("Untitled", "Untitled", new_rows, new_widths, fixed, glyph_width, glyph_height, 1, range_mask_size, new_range_mask, 0, 0, 0, 400, 0, true));
}
NonnullRefPtr<BitmapFont> BitmapFont::unmasked_character_set() const
{
auto* new_range_mask = static_cast<u8*>(malloc(s_max_range_mask_size));
constexpr u8 max_bits { 0b1111'1111 };
memset(new_range_mask, max_bits, s_max_range_mask_size);
size_t bytes_per_glyph = sizeof(u32) * glyph_height();
auto* new_rows = static_cast<u8*>(kmalloc_array(s_max_glyph_count, bytes_per_glyph));
auto* new_widths = static_cast<u8*>(calloc(s_max_glyph_count, 1));
for (size_t code_point = 0; code_point < s_max_glyph_count; ++code_point) {
auto index = glyph_index(code_point);
if (index.has_value()) {
memcpy(&new_widths[code_point], &m_glyph_widths[index.value()], 1);
memcpy(&new_rows[code_point * bytes_per_glyph], &m_rows[index.value() * bytes_per_glyph], bytes_per_glyph);
}
}
return adopt_ref(*new BitmapFont(m_name, m_family, new_rows, new_widths, m_fixed_width, m_glyph_width, m_glyph_height, m_glyph_spacing, s_max_range_mask_size, new_range_mask, m_baseline, m_mean_line, m_presentation_size, m_weight, m_slope, true));
}
NonnullRefPtr<BitmapFont> BitmapFont::masked_character_set() const
{
auto* new_range_mask = static_cast<u8*>(calloc(s_max_range_mask_size, 1));
u16 new_range_mask_size { 0 };
for (size_t i = 0; i < s_max_glyph_count; ++i) {
if (m_glyph_widths[i] > 0) {
new_range_mask[i / 256 / 8] |= 1 << (i / 256 % 8);
if (i / 256 / 8 + 1 > new_range_mask_size)
new_range_mask_size = i / 256 / 8 + 1;
}
}
size_t new_glyph_count { 0 };
for (size_t i = 0; i < new_range_mask_size; ++i) {
new_glyph_count += 256 * popcount(new_range_mask[i]);
}
size_t bytes_per_glyph = sizeof(u32) * m_glyph_height;
auto* new_rows = static_cast<u8*>(calloc(new_glyph_count, bytes_per_glyph));
auto* new_widths = static_cast<u8*>(calloc(new_glyph_count, 1));
for (size_t i = 0, j = 0; i < s_max_glyph_count; ++i) {
if (!(new_range_mask[i / 256 / 8] & 1 << (i / 256 % 8))) {
j++;
i += 255;
continue;
}
memcpy(&new_widths[i - j * 256], &m_glyph_widths[i], 1);
memcpy(&new_rows[(i - j * 256) * bytes_per_glyph], &m_rows[i * bytes_per_glyph], bytes_per_glyph);
}
return adopt_ref(*new BitmapFont(m_name, m_family, new_rows, new_widths, m_fixed_width, m_glyph_width, m_glyph_height, m_glyph_spacing, new_range_mask_size, new_range_mask, m_baseline, m_mean_line, m_presentation_size, m_weight, m_slope, true));
}
BitmapFont::BitmapFont(String name, String family, u8* rows, u8* widths, bool is_fixed_width, u8 glyph_width, u8 glyph_height, u8 glyph_spacing, u16 range_mask_size, u8* range_mask, u8 baseline, u8 mean_line, u8 presentation_size, u16 weight, u8 slope, bool owns_arrays)
: m_name(move(name))
, m_family(move(family))
, m_range_mask_size(range_mask_size)
, m_range_mask(range_mask)
, m_rows(rows)
, m_glyph_widths(widths)
, m_glyph_width(glyph_width)
, m_glyph_height(glyph_height)
, m_min_glyph_width(glyph_width)
, m_max_glyph_width(glyph_width)
, m_glyph_spacing(glyph_spacing)
, m_baseline(baseline)
, m_mean_line(mean_line)
, m_presentation_size(presentation_size)
, m_weight(weight)
, m_slope(slope)
, m_fixed_width(is_fixed_width)
, m_owns_arrays(owns_arrays)
{
VERIFY(m_range_mask);
VERIFY(m_rows);
VERIFY(m_glyph_widths);
update_x_height();
for (size_t i = 0, index = 0; i < m_range_mask_size; ++i) {
for (size_t j = 0; j < 8; ++j) {
if (m_range_mask[i] & (1 << j)) {
m_glyph_count += 256;
m_range_indices.append(index++);
} else {
m_range_indices.append({});
}
}
}
if (!m_fixed_width) {
u8 maximum = 0;
u8 minimum = 255;
for (size_t i = 0; i < m_glyph_count; ++i) {
minimum = min(minimum, m_glyph_widths[i]);
maximum = max(maximum, m_glyph_widths[i]);
}
m_min_glyph_width = minimum;
m_max_glyph_width = max(maximum, m_glyph_width);
}
}
BitmapFont::~BitmapFont()
{
if (m_owns_arrays) {
free(m_glyph_widths);
free(m_rows);
free(m_range_mask);
}
}
RefPtr<BitmapFont> BitmapFont::load_from_memory(u8 const* data)
{
auto const& header = *reinterpret_cast<const FontFileHeader*>(data);
if (memcmp(header.magic, "!Fnt", 4)) {
dbgln("header.magic != '!Fnt', instead it's '{:c}{:c}{:c}{:c}'", header.magic[0], header.magic[1], header.magic[2], header.magic[3]);
return nullptr;
}
if (header.name[sizeof(header.name) - 1] != '\0') {
dbgln("Font name not fully null-terminated");
return nullptr;
}
if (header.family[sizeof(header.family) - 1] != '\0') {
dbgln("Font family not fully null-terminated");
return nullptr;
}
size_t bytes_per_glyph = sizeof(u32) * header.glyph_height;
size_t glyph_count { 0 };
u8* range_mask = const_cast<u8*>(data + sizeof(FontFileHeader));
for (size_t i = 0; i < header.range_mask_size; ++i)
glyph_count += 256 * popcount(range_mask[i]);
u8* rows = range_mask + header.range_mask_size;
u8* widths = (u8*)(rows) + glyph_count * bytes_per_glyph;
return adopt_ref(*new BitmapFont(String(header.name), String(header.family), rows, widths, !header.is_variable_width, header.glyph_width, header.glyph_height, header.glyph_spacing, header.range_mask_size, range_mask, header.baseline, header.mean_line, header.presentation_size, header.weight, header.slope));
}
RefPtr<BitmapFont> BitmapFont::load_from_file(String const& path)
{
if (Core::File::is_device(path))
return nullptr;
auto file_or_error = Core::MappedFile::map(path);
if (file_or_error.is_error())
return nullptr;
auto font = load_from_memory((u8 const*)file_or_error.value()->data());
if (!font)
return nullptr;
font->m_mapped_file = file_or_error.release_value();
return font;
}
bool BitmapFont::write_to_file(String const& path)
{
FontFileHeader header;
memset(&header, 0, sizeof(FontFileHeader));
memcpy(header.magic, "!Fnt", 4);
header.glyph_width = m_glyph_width;
header.glyph_height = m_glyph_height;
header.range_mask_size = m_range_mask_size;
header.baseline = m_baseline;
header.mean_line = m_mean_line;
header.is_variable_width = !m_fixed_width;
header.glyph_spacing = m_glyph_spacing;
header.presentation_size = m_presentation_size;
header.weight = m_weight;
header.slope = m_slope;
memcpy(header.name, m_name.characters(), min(m_name.length(), sizeof(header.name) - 1));
memcpy(header.family, m_family.characters(), min(m_family.length(), sizeof(header.family) - 1));
auto stream_result = Core::OutputFileStream::open_buffered(path);
if (stream_result.is_error())
return false;
auto& stream = stream_result.value();
size_t bytes_per_glyph = sizeof(u32) * m_glyph_height;
stream << ReadonlyBytes { &header, sizeof(header) };
stream << ReadonlyBytes { m_range_mask, m_range_mask_size };
stream << ReadonlyBytes { m_rows, m_glyph_count * bytes_per_glyph };
stream << ReadonlyBytes { m_glyph_widths, m_glyph_count };
stream.flush();
return !stream.handle_any_error();
}
Glyph BitmapFont::glyph(u32 code_point) const
{
// Note: Until all fonts support the 0xFFFD replacement
// character, fall back to painting '?' if necessary.
auto index = glyph_index(code_point).value_or('?');
auto width = m_glyph_widths[index];
return Glyph(
GlyphBitmap(m_rows, index * m_glyph_height, { width, m_glyph_height }),
0,
width,
m_glyph_height);
}
Glyph BitmapFont::raw_glyph(u32 code_point) const
{
auto width = m_glyph_widths[code_point];
return Glyph(
GlyphBitmap(m_rows, code_point * m_glyph_height, { width, m_glyph_height }),
0,
width,
m_glyph_height);
}
Optional<size_t> BitmapFont::glyph_index(u32 code_point) const
{
auto index = code_point / 256;
if (index >= m_range_indices.size())
return {};
if (!m_range_indices[index].has_value())
return {};
return m_range_indices[index].value() * 256 + code_point % 256;
}
bool BitmapFont::contains_glyph(u32 code_point) const
{
auto index = glyph_index(code_point);
return index.has_value() && m_glyph_widths[index.value()] > 0;
}
u8 BitmapFont::glyph_width(u32 code_point) const
{
if (is_ascii(code_point) && !is_ascii_printable(code_point))
return 0;
auto index = glyph_index(code_point);
return m_fixed_width || !index.has_value() ? m_glyph_width : m_glyph_widths[index.value()];
}
int BitmapFont::glyph_or_emoji_width_for_variable_width_font(u32 code_point) const
{
// FIXME: This is a hack in lieu of proper code point identification.
// 0xFFFF is arbitrary but also the end of the Basic Multilingual Plane.
if (code_point < 0xFFFF) {
auto index = glyph_index(code_point);
if (!index.has_value())
return glyph_width(0xFFFD);
if (m_glyph_widths[index.value()] > 0)
return glyph_width(code_point);
return glyph_width(0xFFFD);
}
auto const* emoji = Emoji::emoji_for_code_point(code_point);
if (emoji == nullptr)
return glyph_width(0xFFFD);
return glyph_height() * emoji->width() / emoji->height();
}
int BitmapFont::width(StringView view) const { return unicode_view_width(Utf8View(view)); }
int BitmapFont::width(Utf8View const& view) const { return unicode_view_width(view); }
int BitmapFont::width(Utf32View const& view) const { return unicode_view_width(view); }
template<typename T>
ALWAYS_INLINE int BitmapFont::unicode_view_width(T const& view) const
{
if (view.is_empty())
return 0;
bool first = true;
int width = 0;
int longest_width = 0;
for (u32 code_point : view) {
if (code_point == '\n' || code_point == '\r') {
first = true;
longest_width = max(width, longest_width);
width = 0;
continue;
}
if (!first)
width += glyph_spacing();
first = false;
width += glyph_or_emoji_width(code_point);
}
longest_width = max(width, longest_width);
return longest_width;
}
String BitmapFont::qualified_name() const
{
return String::formatted("{} {} {} {}", family(), presentation_size(), weight(), slope());
}
String BitmapFont::variant() const
{
StringBuilder builder;
builder.append(weight_to_name(weight()));
if (slope() != 0) {
if (builder.string_view() == "Regular"sv)
builder.clear();
else
builder.append(" ");
builder.append(slope_to_name(slope()));
}
return builder.to_string();
}
Font const& Font::bold_variant() const
{
if (m_bold_variant)
return *m_bold_variant;
m_bold_variant = Gfx::FontDatabase::the().get(family(), presentation_size(), 700, 0);
if (!m_bold_variant)
m_bold_variant = this;
return *m_bold_variant;
}
FontMetrics Font::metrics() const
{
return FontMetrics {
.size = (float)presentation_size(),
.x_height = (float)x_height(),
.advance_of_ascii_zero = (float)glyph_width('0'),
.glyph_spacing = (float)glyph_spacing(),
};
}
}