Extract the CGPathRef from a Kanji - text

Question

I would like to get the outline of a Kanji (Japanese) character.
The following code is working for latin characters:
[letter drawInRect:brect withAttributes:attributes];
[...]
CGGlyph glyph;
glyph = [font glyphWithName: letter];
CGPathRef glyphPath = CTFontCreatePathForGlyph((__bridge CTFontRef) font, glyph, NULL);
CGPathAddPath(path0, &transform, glyphPath);
When letter is a Kanji, for example 男, the character is correctly drawn, but the CGPathRef is a square. What do I need to extract the outline of a Kanji ?

Answer 1

The method glyphWithName: expects a glyphName, not the character. For simple latin characters the glyphName is the same as the character – #"A". As far as I know, Kanji do not have names, although hiragana and katakana do. Kanji are simply too numerous, and many of the glyphs are variants on the same Kanji.
So you have to use a different method with Kanji. Here is an example that works for me.
// Convert a single character to a bezier path
- (UIBezierPath *)bezierPathFromChar:(NSString *)aChar inFont:(CTFontRef)aFont {
// Buffers
unichar chars[1];
CGGlyph glyphs[1];
// Copy the character into a buffer
chars[0] = [aChar characterAtIndex:0];
// Encode the glyph for the single character into another buffer
CTFontGetGlyphsForCharacters(aFont, chars, glyphs, 1);
// Get the single glyph
CGGlyph aGlyph = glyphs[0];
// Find a reference to the Core Graphics path for the glyph
CGPathRef glyphPath = CTFontCreatePathForGlyph(aFont, aGlyph, NULL);
// Create a bezier path from the CG path
UIBezierPath *glyphBezierPath = [UIBezierPath bezierPath];
[glyphBezierPath moveToPoint:CGPointZero];
[glyphBezierPath appendPath:[UIBezierPath bezierPathWithCGPath:glyphPath]];
CGPathRelease(glyphPath);
return glyphBezierPath;
}
Use like this:
NSString *theChar = #"男";
CTFontRef font = CTFontCreateWithName(CFSTR("HiraKakuProN-W6"), 114.0, NULL);
UIBezierPath *glyphBezierPath = [self bezierPathFromChar:theChar inFont:font];
Edit - another way of defining the font that can be localized:
CTFontRef font = CTFontCreateWithName((CFStringRef)#"Helvetica-Bold", 114.0, NULL);