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#include <mbgl/text/harfbuzz_shaper.hpp>
#include <harfbuzz/hb.h>
#include <harfbuzz/hb-ft.h>
#include <mutex>
#include <iostream>
// freetype2
extern "C"
{
#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H
#include FT_OUTLINE_H
}
namespace mbgl {
namespace harfbuzz {
RequiredGlyphs getGlyphIDs(hb_font_t* font, const std::string& u8label) {
hb_buffer_t *hb_buffer;
hb_buffer = hb_buffer_create();
hb_buffer_add_utf8(hb_buffer, u8label.c_str(), -1, 0, -1);
hb_buffer_guess_segment_properties(hb_buffer);
hb_shape(font, hb_buffer, NULL, 0);
/* Get glyph information and positions out of the buffer. */
unsigned int len = hb_buffer_get_length(hb_buffer);
hb_glyph_info_t *glyphs = hb_buffer_get_glyph_infos(hb_buffer, NULL);
RequiredGlyphs requiredGlyphs;
for (uint32_t i = 0; i < len; i++)
{
// "codepoint" means "glyph id" after shaping
if (!glyphs[i].codepoint) {
hb_buffer_destroy(hb_buffer);
return RequiredGlyphs(); // There's an invalid glyph in here, fall back to another font
}
requiredGlyphs.insert(glyphs[i].codepoint);
}
hb_buffer_destroy(hb_buffer);
return requiredGlyphs;
}
RequiredGlyphsForFont getGlyphIDs(const LocalFonts& localFonts, const std::string& u8label) {
for (auto localFont : localFonts) {
RequiredGlyphs glyphs = getGlyphIDs(localFont.hb_font, u8label);
if (!glyphs.empty())
return RequiredGlyphsForFont(localFont.id,glyphs);
}
return RequiredGlyphsForFont(localFonts.back().id, RequiredGlyphs()); // All tofu for this label
}
// TODO: This can share a shaping call with getGlyphIDs, although the timing is awkward because the non-Harfbuzz pathway can't do shaping until later when the glyphs have already been downloaded
std::vector<std::pair<char16_t,double>> getClusterWidths(hb_font_t* font, const std::u16string& u16text) {
hb_buffer_t *hb_buffer;
hb_buffer = hb_buffer_create ();
hb_buffer_add_utf16(hb_buffer, reinterpret_cast<const uint16_t*>(u16text.c_str()), -1, 0, -1);
hb_buffer_guess_segment_properties(hb_buffer);
hb_buffer_set_direction(hb_buffer, HB_DIRECTION_LTR); // We set the direction LTR because by the time we get here we've already reversed RTL text with BiDi
hb_shape(font, hb_buffer, NULL, 0);
/* Get glyph information and positions out of the buffer. */
unsigned int len = hb_buffer_get_length(hb_buffer);
hb_glyph_info_t *info = hb_buffer_get_glyph_infos(hb_buffer, NULL);
hb_glyph_position_t *pos = hb_buffer_get_glyph_positions(hb_buffer, NULL);
std::vector<std::pair<char16_t,double>> clusterWidths;
// TODO: Re-write to collect all data in a single pass through info/pos...
for (size_t i = 0; i < u16text.size(); i++) {
double accumulatedWidth = 0;
for (unsigned int j = 0; j < len; j++) {
if (info[j].cluster == i) {
accumulatedWidth += pos[j].x_advance / 64.;
}
}
// NOTE: Some codepoints won't have any glyphs associated with them -- we just make those into zero-width clusters.
clusterWidths.emplace_back(u16text[i],accumulatedWidth);
}
hb_buffer_destroy(hb_buffer);
return clusterWidths;
}
void applyShaping(hb_font_t* font, const std::u16string& u16text, std::vector<PositionedGlyph>& positionedGlyphs, float& current_x, float& current_y) {
hb_buffer_t *hb_buffer;
hb_buffer = hb_buffer_create ();
hb_buffer_add_utf16(hb_buffer, reinterpret_cast<const uint16_t*>(u16text.c_str()), -1, 0, -1);
hb_buffer_guess_segment_properties(hb_buffer);
hb_buffer_set_direction(hb_buffer, HB_DIRECTION_LTR); // We set the direction LTR because by the time we get here we've already reversed RTL text with BiDi
hb_shape(font, hb_buffer, NULL, 0);
/* Get glyph information and positions out of the buffer. */
unsigned int len = hb_buffer_get_length(hb_buffer);
hb_glyph_info_t *info = hb_buffer_get_glyph_infos(hb_buffer, NULL);
hb_glyph_position_t *pos = hb_buffer_get_glyph_positions(hb_buffer, NULL);
for (unsigned int i = 0; i < len; i++)
{
hb_codepoint_t gid = info[i].codepoint; // "codepoint" means "glyph id" after shaping
//unsigned int cluster = info[i].cluster;
double x_advance = pos[i].x_advance / 64.;
double y_advance = pos[i].y_advance / 64.;
double x_offset = pos[i].x_offset / 64.;
double y_offset = pos[i].y_offset / 64.;
positionedGlyphs.emplace_back(gid, current_x + x_offset, current_y + y_offset);
current_x += x_advance;
current_y += y_advance;
}
hb_buffer_destroy(hb_buffer);
}
}
}
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