Add: [OSX] Text layout using the native CoreText API.

By default, the native API will be used instead of ICU, but if ICU is
forced in using configure, it will take precedence.

2 files changed, 307 insertions, 0 deletions

diff --git a/src/os/macosx/string_osx.cpp b/src/os/macosx/string_osx.cpp
index 4698f601b..1c5d55885 100644
--- a/src/os/macosx/string_osx.cpp
+++ b/src/os/macosx/string_osx.cpp
@@ -12,13 +12,269 @@
 #include "../../stdafx.h"
 #include "string_osx.h"
 #include "../../string_func.h"
+#include "../../strings_func.h"
+#include "../../table/control_codes.h"
+#include "../../fontcache.h"
 #include "macos.h"
 
 #include <CoreFoundation/CoreFoundation.h>
 
 
 #if (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5)
+/** Cached current locale. */
 static CFLocaleRef _osx_locale = NULL;
+/** CoreText cache for font information, cleared when OTTD changes fonts. */
+static CTFontRef _font_cache[FS_END];
+
+
+/**
+ * Wrapper for doing layouts with CoreText.
+ */
+class CoreTextParagraphLayout : public ParagraphLayouter {
+private:
+	const CoreTextParagraphLayoutFactory::CharType *text_buffer;
+	ptrdiff_t length;
+	const FontMap& font_map;
+
+	CTTypesetterRef typesetter;
+
+	CFIndex cur_offset = 0; ///< Offset from the start of the current run from where to output.
+
+public:
+	/** Visual run contains data about the bit of text with the same font. */
+	class CoreTextVisualRun : public ParagraphLayouter::VisualRun {
+	private:
+		std::vector<GlyphID> glyphs;
+		std::vector<float> positions;
+		std::vector<int> glyph_to_char;
+
+		int total_advance = 0;
+		Font *font;
+
+	public:
+		CoreTextVisualRun(CTRunRef run, Font *font, const CoreTextParagraphLayoutFactory::CharType *buff);
+
+		virtual const GlyphID *GetGlyphs() const { return &this->glyphs[0]; }
+		virtual const float *GetPositions() const { return &this->positions[0]; }
+		virtual const int *GetGlyphToCharMap() const { return &this->glyph_to_char[0]; }
+
+		virtual const Font *GetFont() const { return this->font;  }
+		virtual int GetLeading() const { return this->font->fc->GetHeight(); }
+		virtual int GetGlyphCount() const { return (int)this->glyphs.size(); }
+		int GetAdvance() const { return this->total_advance; }
+	};
+
+	/** A single line worth of VisualRuns. */
+	class CoreTextLine : public AutoDeleteSmallVector<CoreTextVisualRun *, 4>, public ParagraphLayouter::Line {
+	public:
+		CoreTextLine(CTLineRef line, const FontMap &fontMapping, const CoreTextParagraphLayoutFactory::CharType *buff)
+		{
+			CFArrayRef runs = CTLineGetGlyphRuns(line);
+			for (CFIndex i = 0; i < CFArrayGetCount(runs); i++) {
+				CTRunRef run = (CTRunRef)CFArrayGetValueAtIndex(runs, i);
+
+				/* Extract font information for this run. */
+				CFRange chars = CTRunGetStringRange(run);
+				FontMap::const_iterator map = fontMapping.Begin();
+				while (map < fontMapping.End() - 1 && map->first <= chars.location) map++;
+
+				*this->Append() = new CoreTextVisualRun(run, map->second, buff);
+			}
+			CFRelease(line);
+		}
+
+		virtual int GetLeading() const;
+		virtual int GetWidth() const;
+		virtual int CountRuns() const { return this->Length();  }
+		virtual const VisualRun *GetVisualRun(int run) const { return *this->Get(run);  }
+
+		int GetInternalCharLength(WChar c) const
+		{
+			/* CoreText uses UTF-16 internally which means we need to account for surrogate pairs. */
+			return c >= 0x010000U ? 2 : 1;
+		}
+	};
+
+	CoreTextParagraphLayout(CTTypesetterRef typesetter, const CoreTextParagraphLayoutFactory::CharType *buffer, ptrdiff_t len, const FontMap &fontMapping) : text_buffer(buffer), length(len), font_map(fontMapping), typesetter(typesetter)
+	{
+		this->Reflow();
+	}
+
+	virtual ~CoreTextParagraphLayout()
+	{
+		CFRelease(this->typesetter);
+	}
+
+	virtual void Reflow()
+	{
+		this->cur_offset = 0;
+	}
+
+	virtual const Line *NextLine(int max_width);
+};
+
+
+/** Get the width of an encoded sprite font character.  */
+static CGFloat SpriteFontGetWidth(void *ref_con)
+{
+	FontSize fs = (FontSize)((size_t)ref_con >> 24);
+	WChar c = (WChar)((size_t)ref_con & 0xFFFFFF);
+
+	return GetGlyphWidth(fs, c);
+}
+
+static CTRunDelegateCallbacks _sprite_font_callback = {
+	kCTRunDelegateCurrentVersion, NULL, NULL, NULL,
+	&SpriteFontGetWidth
+};
+
+/* static */ ParagraphLayouter *CoreTextParagraphLayoutFactory::GetParagraphLayout(CharType *buff, CharType *buff_end, FontMap &fontMapping)
+{
+	if (!MacOSVersionIsAtLeast(10, 5, 0)) return NULL;
+
+	/* Can't layout an empty string. */
+	ptrdiff_t length = buff_end - buff;
+	if (length == 0) return NULL;
+
+	/* Can't layout our in-built sprite fonts. */
+	for (FontMap::const_iterator i = fontMapping.Begin(); i != fontMapping.End(); i++) {
+		if (i->second->fc->IsBuiltInFont()) return NULL;
+	}
+
+	/* Make attributed string with embedded font information. */
+	CFMutableAttributedStringRef str = CFAttributedStringCreateMutable(kCFAllocatorDefault, 0);
+	CFAttributedStringBeginEditing(str);
+
+	CFStringRef base = CFStringCreateWithCharactersNoCopy(kCFAllocatorDefault, buff, length, kCFAllocatorNull);
+	CFAttributedStringReplaceString(str, CFRangeMake(0, 0), base);
+	CFRelease(base);
+
+	/* Apply font and colour ranges to our string. This is important to make sure
+	 * that we get proper glyph boundaries on style changes. */
+	int last = 0;
+	for (FontMap::const_iterator i = fontMapping.Begin(); i != fontMapping.End(); i++) {
+		if (i->first - last == 0) continue;
+
+		if (_font_cache[i->second->fc->GetSize()] == NULL) {
+			/* Cache font information. */
+			CFStringRef font_name = CFStringCreateWithCString(kCFAllocatorDefault, i->second->fc->GetFontName(), kCFStringEncodingUTF8);
+			_font_cache[i->second->fc->GetSize()] = CTFontCreateWithName(font_name, i->second->fc->GetFontSize(), NULL);
+			CFRelease(font_name);
+		}
+		CFAttributedStringSetAttribute(str, CFRangeMake(last, i->first - last), kCTFontAttributeName, _font_cache[i->second->fc->GetSize()]);
+
+		CGColorRef color = CGColorCreateGenericGray((uint8)i->second->colour / 255.0f, 1.0f); // We don't care about the real colours, just that they are different.
+		CFAttributedStringSetAttribute(str, CFRangeMake(last, i->first - last), kCTForegroundColorAttributeName, color);
+		CGColorRelease(color);
+
+		/* Install a size callback for our special sprite glyphs. */
+		for (ssize_t c = last; c < i->first; c++) {
+			if (buff[c] >= SCC_SPRITE_START && buff[c] <= SCC_SPRITE_END) {
+				CTRunDelegateRef del = CTRunDelegateCreate(&_sprite_font_callback, (void *)(size_t)(buff[c] | (i->second->fc->GetSize() << 24)));
+				CFAttributedStringSetAttribute(str, CFRangeMake(c, 1), kCTRunDelegateAttributeName, del);
+				CFRelease(del);
+			}
+		}
+
+		last = i->first;
+	}
+	CFAttributedStringEndEditing(str);
+
+	/* Create and return typesetter for the string. */
+	CTTypesetterRef typesetter = CTTypesetterCreateWithAttributedString(str);
+	CFRelease(str);
+
+	return typesetter != NULL ? new CoreTextParagraphLayout(typesetter, buff, length, fontMapping) : NULL;
+}
+
+/* virtual */ const CoreTextParagraphLayout::Line *CoreTextParagraphLayout::NextLine(int max_width)
+{
+	if (this->cur_offset >= this->length) return NULL;
+
+	/* Get line break position, trying word breaking first and breaking somewhere if that doesn't work. */
+	CFIndex len = CTTypesetterSuggestLineBreak(this->typesetter, this->cur_offset, max_width);
+	if (len <= 0) len = CTTypesetterSuggestClusterBreak(this->typesetter, this->cur_offset, max_width);
+
+	/* Create line. */
+	CTLineRef line = CTTypesetterCreateLine(this->typesetter, CFRangeMake(this->cur_offset, len));
+	this->cur_offset += len;
+
+	return line != NULL ? new CoreTextLine(line, this->font_map, this->text_buffer) : NULL;
+}
+
+CoreTextParagraphLayout::CoreTextVisualRun::CoreTextVisualRun(CTRunRef run, Font *font, const CoreTextParagraphLayoutFactory::CharType *buff) : font(font)
+{
+	this->glyphs.resize(CTRunGetGlyphCount(run));
+
+	/* Query map of glyphs to source string index. */
+	CFIndex map[this->glyphs.size()];
+	CTRunGetStringIndices(run, CFRangeMake(0, 0), map);
+
+	this->glyph_to_char.resize(this->glyphs.size());
+	for (size_t i = 0; i < this->glyph_to_char.size(); i++) this->glyph_to_char[i] = (int)map[i];
+
+	CGPoint pts[this->glyphs.size()];
+	CTRunGetPositions(run, CFRangeMake(0, 0), pts);
+	this->positions.resize(this->glyphs.size() * 2 + 2);
+
+	/* Convert glyph array to our data type. At the same time, substitute
+	 * the proper glyphs for our private sprite glyphs. */
+	CGGlyph gl[this->glyphs.size()];
+	CTRunGetGlyphs(run, CFRangeMake(0, 0), gl);
+	for (size_t i = 0; i < this->glyphs.size(); i++) {
+		if (buff[this->glyph_to_char[i]] >= SCC_SPRITE_START && buff[this->glyph_to_char[i]] <= SCC_SPRITE_END) {
+			this->glyphs[i] = font->fc->MapCharToGlyph(buff[this->glyph_to_char[i]]);
+			this->positions[i * 2 + 0] = pts[i].x;
+			this->positions[i * 2 + 1] = font->fc->GetAscender() - font->fc->GetGlyph(this->glyphs[i])->height - 1; // Align sprite glyphs to font baseline.
+		} else {
+			this->glyphs[i] = gl[i];
+			this->positions[i * 2 + 0] = pts[i].x;
+			this->positions[i * 2 + 1] = pts[i].y;
+		}
+	}
+	this->total_advance = (int)CTRunGetTypographicBounds(run, CFRangeMake(0, 0), NULL, NULL, NULL);
+	this->positions[this->glyphs.size() * 2] = this->positions[0] + this->total_advance;
+}
+
+/**
+ * Get the height of the line.
+ * @return The maximum height of the line.
+ */
+int CoreTextParagraphLayout::CoreTextLine::GetLeading() const
+{
+	int leading = 0;
+	for (const CoreTextVisualRun * const *run = this->Begin(); run != this->End(); run++) {
+		leading = max(leading, (*run)->GetLeading());
+	}
+
+	return leading;
+}
+
+/**
+ * Get the width of this line.
+ * @return The width of the line.
+ */
+int CoreTextParagraphLayout::CoreTextLine::GetWidth() const
+{
+	if (this->Length() == 0) return 0;
+
+	int total_width = 0;
+	for (const CoreTextVisualRun * const *run = this->Begin(); run != this->End(); run++) {
+		total_width += (*run)->GetAdvance();
+	}
+
+	return total_width;
+}
+
+
+/** Delete CoreText font reference for a specific font size. */
+void MacOSResetScriptCache(FontSize size)
+{
+	if (_font_cache[size] != NULL) {
+		CFRelease(_font_cache[size]);
+		_font_cache[size] = NULL;
+	}
+}
 
 /** Store current language locale as a CoreFounation locale. */
 void MacOSSetCurrentLocaleName(const char *iso_code)
@@ -174,6 +430,7 @@ int MacOSStringCompare(const char *s1, const char *s2)
 }
 
 #else
+void MacOSResetScriptCache(FontSize size) {}
 void MacOSSetCurrentLocaleName(const char *iso_code) {}
 
 int MacOSStringCompare(const char *s1, const char *s2)
@@ -185,4 +442,9 @@ int MacOSStringCompare(const char *s1, const char *s2)
 {
 	return NULL;
 }
+
+/* static */ ParagraphLayouter *CoreTextParagraphLayoutFactory::GetParagraphLayout(CharType *buff, CharType *buff_end, FontMap &fontMapping)
+{
+	return NULL;
+}
 #endif /* (MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5) */
diff --git a/src/os/macosx/string_osx.h b/src/os/macosx/string_osx.h
index ea7904f54..d632b0a44 100644
--- a/src/os/macosx/string_osx.h
+++ b/src/os/macosx/string_osx.h
@@ -38,7 +38,52 @@ public:
 	static StringIterator *Create();
 };
 
+/**
+ * Helper class to construct a new #CoreTextParagraphLayout.
+ */
+class CoreTextParagraphLayoutFactory {
+public:
+	/** Helper for GetLayouter, to get the right type. */
+	typedef UniChar CharType;
+	/** Helper for GetLayouter, to get whether the layouter supports RTL. */
+	static const bool SUPPORTS_RTL = true;
+
+	/**
+	 * Get the actual ParagraphLayout for the given buffer.
+	 * @param buff The begin of the buffer.
+	 * @param buff_end The location after the last element in the buffer.
+	 * @param fontMapping THe mapping of the fonts.
+	 * @return The ParagraphLayout instance.
+	 */
+	static ParagraphLayouter *GetParagraphLayout(CharType *buff, CharType *buff_end, FontMap &fontMapping);
+
+	/**
+	 * Append a wide character to the internal buffer.
+	 * @param buff        The buffer to append to.
+	 * @param buffer_last The end of the buffer.
+	 * @param c           The character to add.
+	 * @return The number of buffer spaces that were used.
+	 */
+	static size_t AppendToBuffer(CharType *buff, const CharType *buffer_last, WChar c)
+	{
+		if (c >= 0x010000U) {
+			/* Character is encoded using surrogates in UTF-16. */
+			if (buff + 1 <= buffer_last) {
+				buff[0] = (CharType)(((c - 0x010000U) >> 10) + 0xD800);
+				buff[1] = (CharType)(((c - 0x010000U) & 0x3FF) + 0xDC00);
+			} else {
+				/* Not enough space in buffer. */
+				*buff = 0;
+			}
+			return 2;
+		} else {
+			*buff = (CharType)(c & 0xFFFF);
+			return 1;
+		}
+	}
+};
 
+void MacOSResetScriptCache(FontSize size);
 void MacOSSetCurrentLocaleName(const char *iso_code);
 int MacOSStringCompare(const char *s1, const char *s2);