void text_layout::add_line(text_line & line)
{
if (lines_.empty())
{
line.set_first_line(true);
}
height_ += line.height();
glyphs_count_ += line.size();
width_ = std::max(width_, line.width());
lines_.push_back(line);
}
static void shape_text(text_line & line,
text_itemizer & itemizer,
std::map<unsigned,double> & width_map,
face_manager_freetype & font_manager,
double scale_factor)
{
unsigned start = line.first_char();
unsigned end = line.last_char();
std::size_t length = end - start;
if (!length) return;
std::list<text_item> const& list = itemizer.itemize(start, end);
line.reserve(length);
auto hb_buffer_deleter = [](hb_buffer_t * buffer) { hb_buffer_destroy(buffer);};
const std::unique_ptr<hb_buffer_t, decltype(hb_buffer_deleter)> buffer(hb_buffer_create(),hb_buffer_deleter);
hb_buffer_pre_allocate(buffer.get(), safe_cast<int>(length));
mapnik::value_unicode_string const& text = itemizer.text();
for (auto const& text_item : list)
{
face_set_ptr face_set = font_manager.get_face_set(text_item.format_->face_name, text_item.format_->fontset);
double size = text_item.format_->text_size * scale_factor;
face_set->set_unscaled_character_sizes();
std::size_t num_faces = face_set->size();
std::size_t pos = 0;
font_feature_settings const& ff_settings = text_item.format_->ff_settings;
int ff_count = safe_cast<int>(ff_settings.count());
for (auto const& face : *face_set)
{
++pos;
hb_buffer_clear_contents(buffer.get());
hb_buffer_add_utf16(buffer.get(), uchar_to_utf16(text.getBuffer()), text.length(), text_item.start, static_cast<int>(text_item.end - text_item.start));
hb_buffer_set_direction(buffer.get(), (text_item.dir == UBIDI_RTL)?HB_DIRECTION_RTL:HB_DIRECTION_LTR);
hb_buffer_set_script(buffer.get(), _icu_script_to_script(text_item.script));
hb_font_t *font(hb_ft_font_create(face->get_face(), nullptr));
// https://github.com/mapnik/test-data-visual/pull/25
#if HB_VERSION_MAJOR > 0
#if HB_VERSION_ATLEAST(1, 0 , 5)
hb_ft_font_set_load_flags(font,FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING);
#endif
#endif
hb_shape(font, buffer.get(), ff_settings.get_features(), ff_count);
hb_font_destroy(font);
unsigned num_glyphs = hb_buffer_get_length(buffer.get());
hb_glyph_info_t *glyphs = hb_buffer_get_glyph_infos(buffer.get(), nullptr);
hb_glyph_position_t *positions = hb_buffer_get_glyph_positions(buffer.get(), nullptr);
bool font_has_all_glyphs = true;
// Check if all glyphs are valid.
for (unsigned i=0; i<num_glyphs; ++i)
{
if (!glyphs[i].codepoint)
{
font_has_all_glyphs = false;
break;
}
}
if (!font_has_all_glyphs && (pos < num_faces))
{
//Try next font in fontset
continue;
}
double max_glyph_height = 0;
for (unsigned i=0; i<num_glyphs; ++i)
{
auto const& gpos = positions[i];
auto const& glyph = glyphs[i];
unsigned char_index = glyph.cluster;
glyph_info g(glyph.codepoint,char_index,text_item.format_);
if (face->glyph_dimensions(g))
{
g.face = face;
g.scale_multiplier = size / face->get_face()->units_per_EM;
//Overwrite default advance with better value provided by HarfBuzz
g.unscaled_advance = gpos.x_advance;
g.offset.set(gpos.x_offset * g.scale_multiplier, gpos.y_offset * g.scale_multiplier);
double tmp_height = g.height();
if (tmp_height > max_glyph_height) max_glyph_height = tmp_height;
width_map[char_index] += g.advance();
line.add_glyph(std::move(g), scale_factor);
}
}
line.update_max_char_height(max_glyph_height);
break; //When we reach this point the current font had all glyphs.
}
}
}
static void shape_text(text_line & line,
text_itemizer & itemizer,
std::map<unsigned,double> & width_map,
face_manager_freetype & font_manager,
double scale_factor )
{
unsigned start = line.first_char();
unsigned end = line.last_char();
mapnik::value_unicode_string const& text = itemizer.text();
size_t length = end - start;
if (!length) return;
line.reserve(length);
std::list<text_item> const& list = itemizer.itemize(start, end);
UErrorCode err = U_ZERO_ERROR;
mapnik::value_unicode_string shaped;
mapnik::value_unicode_string reordered;
for (auto const& text_item : list)
{
face_set_ptr face_set = font_manager.get_face_set(text_item.format->face_name, text_item.format->fontset);
double size = text_item.format->text_size * scale_factor;
face_set->set_unscaled_character_sizes();
for (auto const& face : *face_set)
{
UBiDi *bidi = ubidi_openSized(length, 0, &err);
ubidi_setPara(bidi, text.getBuffer(), length, UBIDI_DEFAULT_LTR, 0, &err);
ubidi_writeReordered(bidi, reordered.getBuffer(length),
length, UBIDI_DO_MIRRORING, &err);
ubidi_close(bidi);
reordered.releaseBuffer(length);
int32_t num_char = u_shapeArabic(reordered.getBuffer(), length,
shaped.getBuffer(length), length,
U_SHAPE_LETTERS_SHAPE | U_SHAPE_LENGTH_FIXED_SPACES_NEAR |
U_SHAPE_TEXT_DIRECTION_VISUAL_LTR, &err);
if (num_char < 0)
{
MAPNIK_LOG_ERROR(icu_shaper) << " u_shapeArabic returned negative num_char " << num_char;
}
std::size_t num_chars = static_cast<std::size_t>(num_char);
shaped.releaseBuffer(length);
bool shaped_status = true;
if (U_SUCCESS(err) && (num_chars == length))
{
U_NAMESPACE_QUALIFIER StringCharacterIterator iter(shaped);
unsigned i = 0;
for (iter.setToStart(); iter.hasNext();)
{
UChar ch = iter.nextPostInc();
glyph_info tmp;
tmp.offset.clear();
tmp.char_index = i;
tmp.glyph_index = FT_Get_Char_Index(face->get_face(), ch);
if (tmp.glyph_index == 0)
{
shaped_status = false;
break;
}
tmp.face = face;
tmp.format = text_item.format;
face->glyph_dimensions(tmp);
tmp.scale_multiplier = size / face->get_face()->units_per_EM;
width_map[i] += tmp.advance();
line.add_glyph(std::move(tmp), scale_factor);
++i;
}
}
if (!shaped_status) continue;
line.update_max_char_height(face->get_char_height(size));
return;
}
}
}
// In the Unicode string characters are always stored in logical order.
// This makes line breaking easy. One word is added to the current line at a time. Once the line is too long
// we either go back one step or inset the line break at the current position (depending on "wrap_before" setting).
// At the end everything that is left over is added as the final line.
void text_layout::break_line(text_line & line, double wrap_width, unsigned text_ratio, bool wrap_before)
{
shape_text(line);
if (!wrap_width || line.width() < wrap_width)
{
add_line(line);
return;
}
if (text_ratio)
{
double wrap_at;
double string_width = line.width();
double string_height = line.line_height();
for (double i = 1.0; ((wrap_at = string_width/i)/(string_height*i)) > text_ratio && (string_width/i) > wrap_width; i += 1.0) ;
wrap_width = wrap_at;
}
mapnik::value_unicode_string const& text = itemizer_.text();
Locale locale; // TODO: Is the default constructor correct?
UErrorCode status = U_ZERO_ERROR;
BreakIterator *breakitr = BreakIterator::createLineInstance(locale, status);
// Not breaking the text if an error occurs is probably the best thing we can do.
// https://github.com/mapnik/mapnik/issues/2072
if (!U_SUCCESS(status))
{
add_line(line);
MAPNIK_LOG_ERROR(text_layout) << " could not create BreakIterator: " << u_errorName(status);
return;
}
breakitr->setText(text);
double current_line_length = 0;
int last_break_position = static_cast<int>(line.first_char());
for (unsigned i=line.first_char(); i < line.last_char(); ++i)
{
// TODO: character_spacing
std::map<unsigned, double>::const_iterator width_itr = width_map_.find(i);
if (width_itr != width_map_.end())
{
current_line_length += width_itr->second;
}
if (current_line_length <= wrap_width) continue;
int break_position = wrap_before ? breakitr->preceding(i) : breakitr->following(i);
// following() returns a break position after the last word. So DONE should only be returned
// when calling preceding.
if (break_position <= last_break_position || break_position == static_cast<int>(BreakIterator::DONE))
{
// A single word is longer than the maximum line width.
// Violate line width requirement and choose next break position
break_position = breakitr->following(i);
if (break_position == static_cast<int>(BreakIterator::DONE))
{
break_position = line.last_char();
MAPNIK_LOG_ERROR(text_layout) << "Unexpected result in break_line. Trying to recover...\n";
}
}
// Break iterator operates on the whole string, while we only look at one line. So we need to
// clamp break values.
if (break_position < static_cast<int>(line.first_char()))
{
break_position = line.first_char();
}
if (break_position > static_cast<int>(line.last_char()))
{
break_position = line.last_char();
}
text_line new_line(last_break_position, break_position);
clear_cluster_widths(last_break_position, break_position);
shape_text(new_line);
add_line(new_line);
last_break_position = break_position;
i = break_position - 1;
current_line_length = 0;
}
if (last_break_position == static_cast<int>(line.first_char()))
{
// No line breaks => no reshaping required
add_line(line);
}
else if (last_break_position != static_cast<int>(line.last_char()))
{
text_line new_line(last_break_position, line.last_char());
clear_cluster_widths(last_break_position, line.last_char());
shape_text(new_line);
add_line(new_line);
}
}
void text_layout::break_line(text_line & line, char wrap_char, double wrap_width,
unsigned text_ratio, bool wrap_before, bool repeat_wrap_char)
{
shape_text(line);
if (!wrap_width || line.width() < wrap_width)
{
add_line(line);
return;
}
if (text_ratio)
{
double wrap_at;
double string_width = line.width();
double string_height = line.line_height();
for (double i = 1.0; ((wrap_at = string_width/i)/(string_height*i)) > text_ratio && (string_width/i) > wrap_width; i += 1.0) ;
wrap_width = wrap_at;
}
mapnik::value_unicode_string const& text = itemizer_.text();
line_breaker breaker(text, wrap_char);
double current_line_length = 0;
int last_break_position = static_cast<int>(line.first_char());
for (unsigned i=line.first_char(); i < line.last_char(); ++i)
{
std::map<unsigned, double>::const_iterator width_itr = width_map_.find(i);
if (width_itr != width_map_.end())
{
current_line_length += width_itr->second;
}
if (current_line_length <= wrap_width) continue;
int break_position = wrap_before ? breaker.preceding(i) : breaker.following(i);
if (break_position <= last_break_position || break_position == static_cast<int>(BreakIterator::DONE))
{
break_position = breaker.following(i);
if (break_position == static_cast<int>(BreakIterator::DONE))
{
break_position = line.last_char();
}
}
if (break_position < static_cast<int>(line.first_char()))
{
break_position = line.first_char();
}
if (break_position > static_cast<int>(line.last_char()))
{
break_position = line.last_char();
}
text_line new_line(adjust_last_break_position(last_break_position, repeat_wrap_char_), break_position);
clear_cluster_widths(adjust_last_break_position(last_break_position, repeat_wrap_char_), break_position);
shape_text(new_line);
add_line(new_line);
last_break_position = break_position;
i = break_position - 1;
current_line_length = 0;
}
if (last_break_position == static_cast<int>(line.first_char()))
{
add_line(line);
}
else if (last_break_position != static_cast<int>(line.last_char()))
{
text_line new_line(adjust_last_break_position(last_break_position, repeat_wrap_char_), line.last_char());
clear_cluster_widths(adjust_last_break_position(last_break_position, repeat_wrap_char_), line.last_char());
shape_text(new_line);
add_line(new_line);
}
}
