font: support fallback font to display east asia language.

if exitst fallback.font, and font code not exits in the current font and
the replacement font, try get glyph from the fallback font.

Signed-off-by: nx111 <NX111.AimH@gmail.com>

(cherry picked from commit 35a740d)
(cherry picked from commit 7e99dca)

data/fonts/Makefile.am

@@ -1,3 +1,7 @@
 installdir = $(datadir)/fonts
 
-dist_install_DATA = *.ttf
+dist_install_DATA = *.ttf, *.ttc
+
+install-exec-hook:
+    cd $(DESTDIR)$(datadir)/fonts && \
+    $(LN_S) wqy-microhei.ttc fallback.font

lib/gdi/font.cpp

@@ -291,8 +291,11 @@ std::vector<std::string> fontRenderClass::getFontFaces()
 void addFont(const char *filename, const char *alias, int scale_factor, int is_replacement, int renderflags)
 {
 	fontRenderClass::getInstance()->AddFont(filename, alias, scale_factor, renderflags);
-	if (is_replacement)
+	if (is_replacement == 1)
 		eTextPara::setReplacementFont(alias);
+	else if (is_replacement == -1)
+		eTextPara::setFallbackFont(alias);
+
 }
 
 DEFINE_REF(Font);
@@ -568,23 +571,26 @@ eTextPara::~eTextPara()
 
 void eTextPara::setFont(const gFont *font)
 {
-	ePtr<Font> fnt, replacement;
+	ePtr<Font> fnt, replacement, fallback;
 	fontRenderClass::getInstance()->getFont(fnt, font->family.c_str(), font->pointSize);
 	if (!fnt)
 		eWarning("[eTextPara] Font '%s' is missing!", font->family.c_str());
 	fontRenderClass::getInstance()->getFont(replacement, replacement_facename.c_str(), font->pointSize);
-	setFont(fnt, replacement);
+	fontRenderClass::getInstance()->getFont(fallback, fallback_facename.c_str(), font->pointSize);
+	setFont(fnt, replacement, fallback);
 }
 
 std::string eTextPara::replacement_facename;
+std::string eTextPara::fallback_facename;
 std::set<int> eTextPara::forced_replaces;
 
-void eTextPara::setFont(Font *fnt, Font *replacement)
+void eTextPara::setFont(Font *fnt, Font *replacement, Font *fallback)
 {
 	if (!fnt)
 		return;
 	current_font=fnt;
 	replacement_font=replacement;
+	fallback_font=fallback;
 	singleLock s(ftlock);
 
 			// we ask for replacment_font first becauseof the cache
@@ -614,6 +620,19 @@ void eTextPara::setFont(Font *fnt, Font *replacement)
 			return;
 		}
 	}
+	if (fallback_font)
+	{
+		if ((FTC_Manager_LookupFace(fontRenderClass::instance->cacheManager,
+					    fallback_font->scaler.face_id,
+					    &fallback_face) < 0) ||
+		    (FTC_Manager_LookupSize(fontRenderClass::instance->cacheManager,
+					    &fallback_font->scaler,
+					    &fallback_font->size) < 0))
+		{
+			eDebug("[eTextPara] FTC_Manager_Lookup_Size failed!");
+			return;
+		}
+	}
 	previous=0;
 	use_kerning=FT_HAS_KERNING(current_face);
 }
@@ -858,7 +877,14 @@ nprint:				isprintable=0;
 					index=(rflags&RS_DIRECT)? chr : FT_Get_Char_Index(replacement_face, chr);
 
 				if (!index)
-					eDebug("[eTextPara] Unicode U+%4lx not present", chr);
+				{
+					if (fallback_face)
+						index=(rflags&RS_DIRECT)? chr : FT_Get_Char_Index(fallback_face, chr);
+					if (!index)
+						eDebug("[eTextPara] unicode U+%4lx not present", chr);
+					else
+						appendGlyph(fallback_font, fallback_face, index, flags, rflags, border, i == uc_visual.end() - 1, activate_newcolor, newcolor);
+				}
 				else
 					appendGlyph(replacement_font, replacement_face, index, flags, rflags, border, i == uc_visual.end() - 1, activate_newcolor, newcolor);
 			} else

lib/gdi/font.h

@@ -125,11 +125,12 @@ class eLCD;
 class eTextPara: public iObject
 {
 	DECLARE_REF(eTextPara);
-	ePtr<Font> current_font, replacement_font;
-	FT_Face current_face, replacement_face;
+	ePtr<Font> current_font, replacement_font, fallback_font;
+	FT_Face current_face, replacement_face, fallback_face;
 	int use_kerning;
 	int previous;
 	static std::string replacement_facename;
+	static std::string fallback_facename;
 	static std::set<int> forced_replaces;
 
 	eRect area;
@@ -148,11 +149,12 @@ class eTextPara: public iObject
 	int appendGlyph(Font *current_font, FT_Face current_face, FT_UInt glyphIndex, int flags, int rflags, int border, bool last,
 			bool activate_newcolor, unsigned long newcolor);
 	void newLine(int flags);
-	void setFont(Font *font, Font *replacement_font);
+	void setFont(Font *font, Font *replacement_font, Font *fallback_font);
 	void calc_bbox();
 public:
 	eTextPara(eRect area, ePoint start=ePoint(-1, -1))
 		: current_font(0), replacement_font(0), current_face(0), replacement_face(0),
+		fallback_font(0), fallback_face(0),
 		area(area), cursor(start), maximum(0, 0), left(start.x()), charCount(0), totalheight(0),
 		bboxValid(0), doTopBottomReordering(false)
 	{
@@ -162,6 +164,8 @@ class eTextPara: public iObject
 	static void setReplacementFont(std::string font) { replacement_facename=font; }
 	static void forceReplacementGlyph(int unicode) { forced_replaces.insert(unicode); }
 
+	static void setFallbackFont(std::string font) { fallback_facename=font; }
+
 	void setFont(const gFont *font);
 	int renderString(const char *string, int flags=0, int border=0);