Codechange: split implementations of ParagraphLayouterFactory into their own file

src/gfx_layout_icu.cpp

@@ -0,0 +1,181 @@
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file gfx_layout_icu.cpp Handling of laying out text with ICU. */
+
+#include "stdafx.h"
+
+#include "gfx_layout_icu.h"
+
+#include <unicode/ustring.h>
+
+#include "safeguards.h"
+
+/* Implementation details of LEFontInstance */
+
+le_int32 Font::getUnitsPerEM() const
+{
+	return this->fc->GetUnitsPerEM();
+}
+
+le_int32 Font::getAscent() const
+{
+	return this->fc->GetAscender();
+}
+
+le_int32 Font::getDescent() const
+{
+	return -this->fc->GetDescender();
+}
+
+le_int32 Font::getLeading() const
+{
+	return this->fc->GetHeight();
+}
+
+float Font::getXPixelsPerEm() const
+{
+	return (float)this->fc->GetHeight();
+}
+
+float Font::getYPixelsPerEm() const
+{
+	return (float)this->fc->GetHeight();
+}
+
+float Font::getScaleFactorX() const
+{
+	return 1.0f;
+}
+
+float Font::getScaleFactorY() const
+{
+	return 1.0f;
+}
+
+const void *Font::getFontTable(LETag tableTag) const
+{
+	size_t length;
+	return this->getFontTable(tableTag, length);
+}
+
+const void *Font::getFontTable(LETag tableTag, size_t &length) const
+{
+	return this->fc->GetFontTable(tableTag, length);
+}
+
+LEGlyphID Font::mapCharToGlyph(LEUnicode32 ch) const
+{
+	if (IsTextDirectionChar(ch)) return 0;
+	return this->fc->MapCharToGlyph(ch);
+}
+
+void Font::getGlyphAdvance(LEGlyphID glyph, LEPoint &advance) const
+{
+	advance.fX = glyph == 0xFFFF ? 0 : this->fc->GetGlyphWidth(glyph);
+	advance.fY = 0;
+}
+
+le_bool Font::getGlyphPoint(LEGlyphID glyph, le_int32 pointNumber, LEPoint &point) const
+{
+	return false;
+}
+
+/**
+ * Wrapper for doing layouts with ICU.
+ */
+class ICUParagraphLayout : public ParagraphLayouter {
+	icu::ParagraphLayout *p; ///< The actual ICU paragraph layout.
+public:
+	/** Visual run contains data about the bit of text with the same font. */
+	class ICUVisualRun : public ParagraphLayouter::VisualRun {
+		const icu::ParagraphLayout::VisualRun *vr; ///< The actual ICU vr.
+
+	public:
+		ICUVisualRun(const icu::ParagraphLayout::VisualRun *vr) : vr(vr) { }
+
+		const Font *GetFont() const override          { return (const Font*)vr->getFont(); }
+		int GetGlyphCount() const override            { return vr->getGlyphCount(); }
+		const GlyphID *GetGlyphs() const override     { return vr->getGlyphs(); }
+		const float *GetPositions() const override    { return vr->getPositions(); }
+		int GetLeading() const override               { return vr->getLeading(); }
+		const int *GetGlyphToCharMap() const override { return vr->getGlyphToCharMap(); }
+	};
+
+	/** A single line worth of VisualRuns. */
+	class ICULine : public std::vector<ICUVisualRun>, public ParagraphLayouter::Line {
+		icu::ParagraphLayout::Line *l; ///< The actual ICU line.
+
+	public:
+		ICULine(icu::ParagraphLayout::Line *l) : l(l)
+		{
+			for (int i = 0; i < l->countRuns(); i++) {
+				this->emplace_back(l->getVisualRun(i));
+			}
+		}
+		~ICULine() override { delete l; }
+
+		int GetLeading() const override { return l->getLeading(); }
+		int GetWidth() const override   { return l->getWidth(); }
+		int CountRuns() const override  { return l->countRuns(); }
+		const ParagraphLayouter::VisualRun &GetVisualRun(int run) const override { return this->at(run); }
+
+		int GetInternalCharLength(WChar c) const override
+		{
+			/* ICU uses UTF-16 internally which means we need to account for surrogate pairs. */
+			return Utf8CharLen(c) < 4 ? 1 : 2;
+		}
+	};
+
+	ICUParagraphLayout(icu::ParagraphLayout *p) : p(p) { }
+	~ICUParagraphLayout() override { delete p; }
+	void Reflow() override  { p->reflow(); }
+
+	std::unique_ptr<const Line> NextLine(int max_width) override
+	{
+		icu::ParagraphLayout::Line *l = p->nextLine(max_width);
+		return std::unique_ptr<const Line>(l == nullptr ? nullptr : new ICULine(l));
+	}
+};
+
+/* static */ ParagraphLayouter *ICUParagraphLayoutFactory::GetParagraphLayout(UChar *buff, UChar *buff_end, FontMap &fontMapping)
+{
+	int32 length = buff_end - buff;
+
+	if (length == 0) {
+		/* ICU's ParagraphLayout cannot handle empty strings, so fake one. */
+		buff[0] = ' ';
+		length = 1;
+		fontMapping.back().first++;
+	}
+
+	/* Fill ICU's FontRuns with the right data. */
+	icu::FontRuns runs(fontMapping.size());
+	for (auto &pair : fontMapping) {
+		runs.add(pair.second, pair.first);
+	}
+
+	LEErrorCode status = LE_NO_ERROR;
+	/* ParagraphLayout does not copy "buff", so it must stay valid.
+		* "runs" is copied according to the ICU source, but the documentation does not specify anything, so this might break somewhen. */
+	icu::ParagraphLayout *p = new icu::ParagraphLayout(buff, length, &runs, nullptr, nullptr, nullptr, _current_text_dir == TD_RTL ? 1 : 0, false, status);
+	if (status != LE_NO_ERROR) {
+		delete p;
+		return nullptr;
+	}
+
+	return new ICUParagraphLayout(p);
+}
+
+/* static */ size_t ICUParagraphLayoutFactory::AppendToBuffer(UChar *buff, const UChar *buffer_last, WChar c)
+{
+	/* Transform from UTF-32 to internal ICU format of UTF-16. */
+	int32 length = 0;
+	UErrorCode err = U_ZERO_ERROR;
+	u_strFromUTF32(buff, buffer_last - buff, &length, (UChar32*)&c, 1, &err);
+	return length;
+}