Function GetLayouter

src/gfx_layout.cpp:65–121

 */
template <typename T>
static inline void GetLayouter(Layouter::LineCacheItem &line, std::string_view str, FontState &state)
{
	typename T::CharType *buff_begin = new typename T::CharType[str.size() + 1];
	/* Move ownership of buff_begin into the Buffer/unique_ptr. */
	line.buffer = Layouter::LineCacheItem::Buffer(buff_begin, [](void *p) { delete[] reinterpret_cast<T::CharType *>(p); });

	const typename T::CharType *buffer_last = buff_begin + str.size() + 1;
	typename T::CharType *buff = buff_begin;
	FontMap &font_mapping = line.runs;
	Font *f = Layouter::GetFont(state.fontsize, state.cur_colour);

	font_mapping.clear();

	/*
	 * Go through the whole string while adding Font instances to the font map
	 * whenever the font changes, and convert the wide characters into a format
	 * usable by ParagraphLayout.
	 */
	for (char32_t c : Utf8View(str)) {
		if (c == '\0' || c == '\n') {
			/* Caller should already have filtered out these characters. */
			NOT_REACHED();
		} else if (c >= SCC_BLUE && c <= SCC_BLACK) {
			state.SetColour((TextColour)(c - SCC_BLUE));
		} else if (c == SCC_PUSH_COLOUR) {
			state.PushColour();
		} else if (c == SCC_POP_COLOUR) {
			state.PopColour();
		} else if (c >= SCC_FIRST_FONT && c <= SCC_LAST_FONT) {
			state.SetFontSize((FontSize)(c - SCC_FIRST_FONT));
		} else {
			/* Filter out non printable characters */
			if (!IsPrintable(c)) continue;
			/* Filter out text direction characters that shouldn't be drawn, and
			 * will not be handled in the fallback case because they are mostly
			 * needed for RTL languages which need more proper shaping support. */
			if (!T::SUPPORTS_RTL && IsTextDirectionChar(c)) continue;
			buff += T::AppendToBuffer(buff, buffer_last, c);
			if (buff >= buffer_last) break;
			continue;
		}

		if (font_mapping.empty() || font_mapping.back().first != buff - buff_begin) {
			font_mapping.emplace_back(buff - buff_begin, f);
		}
		f = Layouter::GetFont(state.fontsize, state.cur_colour);
	}

	/* Better safe than sorry. */
	*buff = '\0';

	if (font_mapping.empty() || font_mapping.back().first != buff - buff_begin) {
		font_mapping.emplace_back(buff - buff_begin, f);
	}
	line.layout = T::GetParagraphLayout(buff_begin, buff, font_mapping);
	line.state_after = state;
}