new font fallback implementation - it is rather inefficient but attempting to do a right thing.

(NOTE: some visual text failures need further look to see if latest implementation is correct)
This commit is contained in:
artemp 2017-02-17 14:17:20 +01:00
parent a5f00c6fa1
commit 49c28cb6ad

View file

@ -85,7 +85,6 @@ static void shape_text(text_line & line,
mapnik::value_unicode_string const& text = itemizer.text();
for (auto const& text_item : list)
{
auto item_length = static_cast<int>(text_item.end - text_item.start);
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();
@ -101,22 +100,24 @@ static void shape_text(text_line & line,
hb_glyph_info_t glyph;
hb_glyph_position_t position;
};
// this table is filled with information for rendering each glyph, so that
// several font faces can be used in a single text_item
std::vector<glyph_face_info> glyphinfos;
int valid_glyphs = 0;
std::size_t pos = 0;
std::map<unsigned, std::vector<glyph_face_info>> glyphinfos;
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, item_length);
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 && HB_VERSION_ATLEAST(1, 0, 5))
hb_ft_font_set_load_flags(font, FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING);
hb_ft_font_set_load_flags(font,FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING);
#endif
hb_shape(font, buffer.get(), ff_settings.get_features(), ff_count);
hb_font_destroy(font);
@ -125,51 +126,113 @@ static void shape_text(text_line & line,
hb_glyph_info_t *glyphs = hb_buffer_get_glyph_infos(buffer.get(), &num_glyphs);
hb_glyph_position_t *positions = hb_buffer_get_glyph_positions(buffer.get(), &num_glyphs);
// if the number of rendered glyphs has increased, we need to resize the table
if (num_glyphs > glyphinfos.size())
{
glyphinfos.resize(num_glyphs);
}
// Check if all glyphs are valid.
unsigned cluster = 0;
bool in_cluster = false;
std::vector<unsigned> clusters;
for (unsigned i = 0; i < num_glyphs; ++i)
{
if (i == 0)
{
cluster = glyphs[0].cluster;
clusters.push_back(cluster);
}
if (cluster != glyphs[i].cluster)
{
cluster = glyphs[i].cluster;
clusters.push_back(cluster);
in_cluster = false;
}
else if (i != 0)
{
in_cluster = true;
}
// if we have a valid codepoint, save rendering info.
if (glyphs[i].codepoint)
{
if (!glyphinfos[i].glyph.codepoint)
auto itr = glyphinfos.find(cluster);
if (itr == glyphinfos.end())
{
++valid_glyphs;
glyphinfos[i] = { face, glyphs[i], positions[i] };
std::vector<glyph_face_info> v = {{ face, glyphs[i], positions[i] }};
bool result = false;
std::tie(itr, result) = glyphinfos.insert(std::make_pair(cluster, v));
}
if (itr->second.front().glyph.codepoint == 0)
{
itr->second.front() = { face, glyphs[i], positions[i] };
}
else if (in_cluster)
{
itr->second.push_back({ face, glyphs[i], positions[i] });
}
}
else
{
auto itr = glyphinfos.find(cluster);
if (itr == glyphinfos.end())
{
std::vector<glyph_face_info> v = {{ face, glyphs[i], positions[i] }};
bool result = false;
std::tie(itr, result) = glyphinfos.insert(std::make_pair(cluster, v));
}
if (itr != glyphinfos.end() && itr->second.front().glyph.codepoint == 0)
{
itr->second.front() = { face, glyphs[i], positions[i] };
}
}
}
if (valid_glyphs < item_length && (pos < num_faces))
bool all_set = true;
for (auto c : clusters)
{
auto itr = glyphinfos.find(c);
if (itr == glyphinfos.end())
{
all_set = false;
break;
}
if (!itr->second.empty() && itr->second.front().glyph.codepoint == 0)
{
all_set = false;
break;
}
}
if (!all_set && (pos < num_faces))
{
//Try next font in fontset
continue;
}
double max_glyph_height = 0;
for (auto const& info : glyphinfos)
for (auto const& c : clusters)
{
if (info.glyph.codepoint)
auto itr = glyphinfos.find(c);
if (itr != glyphinfos.end())
{
auto const& gpos = info.position;
auto const& glyph = info.glyph;
auto const& theface = info.face;
unsigned char_index = glyph.cluster;
glyph_info g(glyph.codepoint, char_index, text_item.format_);
if (theface->glyph_dimensions(g))
for (auto const& info : itr->second)
{
g.face = theface;
g.scale_multiplier = size / theface->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);
face_ptr theface = face;
auto & gpos = info.position;
auto & glyph = info.glyph;
if (info.glyph.codepoint != 0)
{
theface = info.face;
}
unsigned char_index = glyph.cluster;
glyph_info g(glyph.codepoint,char_index,text_item.format_);
if (theface->glyph_dimensions(g))
{
g.face = theface;
g.scale_multiplier = size / theface->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);
}
}
}
}