Method GetParagraphLayout

src/os/windows/string_uniscribe.cpp:277–317

static */

}

/* static */ std::unique_ptr<ParagraphLayouter> UniscribeParagraphLayoutFactory::GetParagraphLayout(CharType *buff, CharType *buff_end, FontMap &font_mapping)
{
	int32_t length = buff_end - buff;
	/* Can't layout an empty string. */
	if (length == 0) return nullptr;

	/* Can't layout our in-built sprite fonts. */
	for (auto const &[position, font] : font_mapping) {
		if (font->fc->IsBuiltInFont()) return nullptr;
	}

	/* Itemize text. */
	std::vector<SCRIPT_ITEM> items = UniscribeItemizeString(buff, length);
	if (items.empty()) return nullptr;

	/* Build ranges from the items and the font map. A range is a run of text
	 * that is part of a single item and formatted using a single font style. */
	std::vector<UniscribeRun> ranges;

	int cur_pos = 0;
	std::vector<SCRIPT_ITEM>::iterator cur_item = items.begin();
	for (auto const &[position, font] : font_mapping) {
		while (cur_pos < position && cur_item != items.end() - 1) {
			/* Add a range that spans the intersection of the remaining item and font run. */
			int stop_pos = std::min(position, (cur_item + 1)->iCharPos);
			assert(stop_pos - cur_pos > 0);
			ranges.emplace_back(cur_pos, stop_pos - cur_pos, font, cur_item->a);

			/* Shape the range. */
			if (!UniscribeShapeRun(buff, ranges.back())) {
				return nullptr;
			}

			/* If we are at the end of the current item, advance to the next item. */
			if (stop_pos == (cur_item + 1)->iCharPos) cur_item++;
			cur_pos = stop_pos;
		}
	}

	return std::make_unique<UniscribeParagraphLayout>(std::move(ranges), buff);
}

/* virtual */ std::unique_ptr<const ParagraphLayouter::Line> UniscribeParagraphLayout::NextLine(int max_width)
{