back: implement coveredCharacterSet for CairoFontInfo

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/back/trunk@32716 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,18 @@
+2011-03-27  Eric Wasylishen  <ewasylishen@gmail.com>
+
+	* Source/cairo/CairoFontEnumerator.m:
+	* Source/cairo/CairoFaceInfo.m:
+	* Source/cairo/CairoFontInfo.m:
+	* Headers/cairo/CairoFontEnumerator.h:
+	* Headers/cairo/CairoFaceInfo.h: Set the coveredCharacterSet ivar
+	of CairoFontInfo. The character set is obtained from Fontconfig.
+	There is an NSCharacterSet subclass which wraps the FcCharSet
+	structure from fontconfig, so there is no need for a slow conversion
+	from one character set format to another.
+
+	This has the effect of enabling glyph substitution when using
+	the cairo backend.
+
 2011-03-23 Fred Kiefer <FredKiefer@gmx.de>
 
 	* Tools/xpbs.m (-pasteboard:provideDataForType:, -availableTypes)

Headers/cairo/CairoFaceInfo.h

@@ -64,5 +64,7 @@
 
 - (cairo_font_face_t *)fontFace;
 
+- (NSCharacterSet*)characterSet;
+
 @end
 #endif

Headers/cairo/CairoFontEnumerator.h

@@ -30,10 +30,21 @@
 
 #include <GNUstepGUI/GSFontInfo.h>
 #include <cairo.h>
+#include <fontconfig/fontconfig.h>
 #include "cairo/CairoFaceInfo.h"
 
 @interface CairoFontEnumerator : GSFontEnumerator
 + (CairoFaceInfo *) fontWithName: (NSString *)name;
 @end
 
+@interface FontconfigCharacterSet : NSCharacterSet
+{
+  FcCharSet *_charset;
+}
+
+- (id)initWithFontconfigCharSet: (FcCharSet*)charset;
+- (FcCharSet*)fontconfigCharSet;
+
+@end
+
 #endif

Source/cairo/CairoFaceInfo.m

@@ -29,6 +29,7 @@
 */
 
 #include "cairo/CairoFaceInfo.h"
+#include "cairo/CairoFontEnumerator.h"
 #include <cairo-ft.h>
 #include <AppKit/NSFontManager.h>
 
@@ -122,4 +123,24 @@
   return _fontFace;
 }
 
+- (NSCharacterSet*)characterSet
+{
+  FcResult result;
+  FcPattern *resolved;
+  FcCharSet *charset;
+  NSCharacterSet *characterSet = nil;
+
+  FcConfigSubstitute(NULL, _pattern, FcMatchPattern); 
+  FcDefaultSubstitute(_pattern);
+  resolved = FcFontMatch(NULL, _pattern, &result);
+
+  if (FcResultMatch == FcPatternGetCharSet(resolved, FC_CHARSET, 0, &charset))
+    {
+      characterSet = [[[FontconfigCharacterSet alloc] initWithFontconfigCharSet: charset] autorelease];
+    }  
+  
+  FcPatternDestroy(resolved);
+  return characterSet;
+}
+
 @end

Source/cairo/CairoFontEnumerator.m

@@ -236,3 +236,48 @@ static NSArray *faFromFc(FcPattern *pat)
 }
 
 @end
+
+@implementation FontconfigCharacterSet
+
+- (id)initWithFontconfigCharSet: (FcCharSet*)charset
+{
+  if ((self = [super init]))
+    {
+      _charset = FcCharSetCopy(charset);
+    }
+  return self;
+}
+
+- (id)mutableCopyWithZone: (NSZone*)aZone
+{
+  return [[NSMutableCharacterSet characterSetWithBitmapRepresentation: 
+				   [self bitmapRepresentation]] retain];
+}
+
+- (void)dealloc
+{
+  FcCharSetDestroy(_charset);
+  [super dealloc];
+}
+
+- (FcCharSet*)fontconfigCharSet
+{
+  return _charset;
+}
+
+- (BOOL)characterIsMember: (unichar)c
+{
+  return FcCharSetHasChar(_charset, c);
+}
+
+- (BOOL)longCharacterIsMember: (UTF32Char)c
+{
+  return FcCharSetHasChar(_charset, c);
+}
+
+// FIXME: Implement for better performance
+//- (NSData *)bitmapRepresentation
+//{
+//}
+
+@end

Source/cairo/CairoFontInfo.m

@@ -79,7 +79,7 @@
 
   /* setting GSFontInfo:
    * weight, traits, familyName,
-   * mostCompatibleStringEncoding, encodingScheme,
+   * mostCompatibleStringEncoding, encodingScheme, coveredCharacterSet
    */
 
   weight = [_faceInfo weight];
@@ -87,6 +87,8 @@
   familyName = [[_faceInfo familyName] copy];
   mostCompatibleStringEncoding = NSUTF8StringEncoding;
   encodingScheme = @"iso10646-1";
+  coveredCharacterSet = [[_faceInfo characterSet] retain];
+
 
   /* setting GSFontInfo:
    * xHeight, pix_width, pix_height