Method Shape

src/gfx_layout_icu.cpp:150–211

* Shape a single run. * * @param buff The buffer of which a partial (depending on start/length of the run) will be shaped. * @param length The length of the buffer. */

 * @param length The length of the buffer.
 */
void ICURun::Shape(UChar *buff, size_t buff_length)
{
	auto hbfont = hb_ft_font_create_referenced(*(static_cast<const FT_Face *>(font->fc->GetOSHandle())));
	/* Match the flags with how we render the glyphs. */
	hb_ft_font_set_load_flags(hbfont, GetFontAAState() ? FT_LOAD_TARGET_NORMAL : FT_LOAD_TARGET_MONO);

	/* ICU buffer is in UTF-16. */
	auto hbbuf = hb_buffer_create();
	hb_buffer_add_utf16(hbbuf, reinterpret_cast<uint16_t *>(buff), buff_length, this->start, this->length);

	/* Set all the properties of this segment. */
	hb_buffer_set_direction(hbbuf, (this->level & 1) == 1 ? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
	hb_buffer_set_script(hbbuf, hb_script_from_string(uscript_getShortName(this->script), -1));
	hb_buffer_set_language(hbbuf, hb_language_from_string(_current_language->isocode, -1));
	hb_buffer_set_cluster_level(hbbuf, HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES);

	/* Shape the segment. */
	hb_shape(hbfont, hbbuf, nullptr, 0);

	unsigned int glyph_count;
	auto glyph_info = hb_buffer_get_glyph_infos(hbbuf, &glyph_count);
	auto glyph_pos = hb_buffer_get_glyph_positions(hbbuf, &glyph_count);

	/* Make sure any former run is lost. */
	this->glyphs.clear();
	this->glyph_to_char.clear();
	this->positions.clear();
	this->advance.clear();

	/* Reserve space, as we already know the size. */
	this->glyphs.reserve(glyph_count);
	this->glyph_to_char.reserve(glyph_count);
	this->positions.reserve(glyph_count);
	this->advance.reserve(glyph_count);

	/* Prepare the glyphs/position. ICUVisualRun will give the position an offset if needed. */
	hb_position_t advance = 0;
	for (unsigned int i = 0; i < glyph_count; i++) {
		int x_advance;

		if (buff[glyph_info[i].cluster] >= SCC_SPRITE_START && buff[glyph_info[i].cluster] <= SCC_SPRITE_END && glyph_info[i].codepoint == 0) {
			auto glyph = this->font->fc->MapCharToGlyph(buff[glyph_info[i].cluster]);
			x_advance = this->font->fc->GetGlyphWidth(glyph);
			this->glyphs.push_back(glyph);
			this->positions.emplace_back(advance, advance + x_advance - 1, (this->font->fc->GetHeight() - ScaleSpriteTrad(FontCache::GetDefaultFontHeight(this->font->fc->GetSize()))) / 2); // Align sprite font to centre
		} else {
			x_advance = glyph_pos[i].x_advance / FONT_SCALE;
			this->glyphs.push_back(glyph_info[i].codepoint);
			this->positions.emplace_back(glyph_pos[i].x_offset / FONT_SCALE + advance, glyph_pos[i].x_offset / FONT_SCALE + advance + x_advance - 1, glyph_pos[i].y_offset / FONT_SCALE);
		}

		this->glyph_to_char.push_back(glyph_info[i].cluster);
		this->advance.push_back(x_advance);
		advance += x_advance;
	}

	/* Track the total advancement we made. */
	this->total_advance = advance;