我试图使用各种技术在MacOS X / iOS中获取角色的边界框.我现在正在展示我的所有尝试.到目前为止,如果我想获得像“Ä”这样的变音字符的大小,代码就会失败.
使用CTFontGetBoundingRectsForGlyphs
-(void) resizeLayer1:(CATextLayer *)l toString:(Nsstring *)string { // need to set CGFont explicitly to convert font property to a CGFontRef CGFontRef layerFont = CGFontCreateWithFontName((CFStringRef)@"Helvetica"); l.font = layerFont; string = l.string; NSUInteger len = [string length]; // get characters from Nsstring UniChar *characters = (UniChar *)malloc(sizeof(UniChar)*len); CFStringGetCharacters((__bridge CFStringRef)l.string,CFRangeMake(0,[l.string length]),characters); // Get CTFontRef from CGFontRef CTFontRef coreTextFont = CTFontCreateWithGraphicsFont(layerFont,l.fontSize,NULL,NULL); // allocate glyphs and bounding Box arrays for holding the result // assuming that each character is only one glyph,which is wrong CGGlyph *glyphs = (CGGlyph *)malloc(sizeof(CGGlyph)*len); CTFontGetGlyphsForCharacters(coreTextFont,characters,glyphs,len); // get bounding Boxes for glyphs CGRect *bb = (CGRect *)malloc(sizeof(CGRect)*len); CTFontGetBoundingRectsForGlyphs(coreTextFont,kCTFontDefaultOrientation,bb,len); CFRelease(coreTextFont); l.position = CGPointMake(200.f,100.f); l.bounds = bb[0]; l.backgroundColor = CGColorCreateGenericRGB(0.f,.5f,.9f,1.f); free(characters); free(glyphs); free(bb); }
结果它有点工作,但有一些填充正在进行,因为字形由CATextLayer呈现
使用CTFramesetterSuggestFrameSizeWithConstraints
-(void) resizeLayer2:(CATextLayer *)l toString:(Nsstring *)string { // need to set CGFont explicitly to convert font property to a CGFontRef CGFontRef layerFont = CGFontCreateWithFontName((CFStringRef)@"Helvetica"); l.font = layerFont; string = l.string; NSUInteger len = [string length]; // get characters from Nsstring UniChar *characters = (UniChar *)malloc(sizeof(UniChar)*len); CFStringGetCharacters((__bridge CFStringRef)l.string,NULL); CFMutableAttributedStringRef attrStr = CFAttributedStringCreateMutable(kcfAllocatorDefault,0); CFAttributedStringReplaceString(attrStr,0),(__bridge CFStringRef)string); CTTextAlignment alignment = kCTJustifiedTextAlignment; CTParagraphStyleSetting _settings[] = { {kCTParagraphStyleSpecifierAlignment,sizeof(alignment),&alignment} }; CTParagraphStyleRef paragraphStyle = CTParagraphStyleCreate(_settings,sizeof(_settings) / sizeof(_settings[0])); CFAttributedStringSetAttribute(attrStr,CFAttributedStringGetLength(attrStr)),kCTParagraphStyleAttributeName,paragraphStyle); CFAttributedStringSetAttribute(attrStr,kCTFontAttributeName,coreTextFont); CFRelease(paragraphStyle); CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(attrStr); CFRelease(attrStr); CFRange range; CGFloat maxWidth = CGFLOAT_MAX; CGFloat maxHeight = 10000.f; CGSize constraint = CGSizeMake(maxWidth,maxHeight); // checking frame sizes CGSize coreTextSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetter,len),nil,constraint,&range); // allocate glyphs and bounding Box arrays for holding the result // assuming that each character is only one glyph,len); CFRelease(coreTextFont); bb[0].origin = l.bounds.origin; coreTextSize.width = ceilf(coreTextSize.width); coreTextSize.height = ceilf(coreTextSize.height); bb[0].size = coreTextSize; l.position = CGPointMake(200.f,100.f); // after setting the bounds the layer gets transparent l.bounds = bb[0]; l.opaque = YES; return; l.backgroundColor = CGColorCreateGenericRGB(0.f,1.f); free(characters); free(glyphs); free(bb); }
结果字符串的边界框是正确的.变音符号存在问题：Ä缺少其点,因为边界框不够高.
使用CTLineGetTypographicBounds
-(void) resizeLayer3:(CATextLayer *)l toString:(Nsstring *)string { // need to set CGFont explicitly to convert font property to a CGFontRef CGFontRef layerFont = CGFontCreateWithFontName((CFStringRef)@"Helvetica"); l.font = layerFont; string = l.string; NSUInteger len = [string length]; // get characters from Nsstring UniChar *characters = (UniChar *)malloc(sizeof(UniChar)*len); CFStringGetCharacters((__bridge CFStringRef)l.string,(__bridge CFStringRef)string); CFAttributedStringSetAttribute(attrStr,coreTextFont); CTLineRef line = CTLineCreateWithAttributedString(attrStr); CGFloat ascent; CGFloat descent; CGFloat width = CTLineGetTypographicBounds(line,&ascent,&descent,NULL); CGFloat height = ascent+descent; CGSize coreTextSize = CGSizeMake(width,height); // get bounding Boxes for glyphs CGRect *bb = (CGRect *)malloc(sizeof(CGRect)*len); CFRelease(coreTextFont); bb[0].origin = CGPointZero; coreTextSize.width = ceilf(coreTextSize.width); coreTextSize.height = ceilf(coreTextSize.height); bb[0].size = coreTextSize; l.position = CGPointMake(200.f,1.f); free(characters); free(bb); }
结果字符串的边界框是正确的.变音符号存在问题：Ä缺少其点,因为边界框不够高.
使用CTFontGetBoundingRectsForGlyphs
-(void) resizeLayer4:(CATextLayer *)l toString:(Nsstring *)string { // need to set CGFont explicitly to convert font property to a CGFontRef CGFontRef layerFont = CGFontCreateWithFontName((CFStringRef)@"Helvetica"); l.font = layerFont; string = l.string; NSUInteger len = [string length]; // get characters from Nsstring UniChar *characters = (UniChar *)malloc(sizeof(UniChar)*len); CFStringGetCharacters((__bridge CFStringRef)l.string,len); CGPathRef glyPHPath = CTFontCreatePathForGlyph(coreTextFont,glyphs[1],NULL); CGRect rect = CGPathGetBoundingBox(glyPHPath); // get bounding Boxes for glyphs CGRect *bb = (CGRect *)malloc(sizeof(CGRect)*len); CTFontGetBoundingRectsForGlyphs(coreTextFont,100.f); l.bounds = rect; l.backgroundColor = CGColorCreateGenericRGB(0.f,1.f); free(characters); free(glyphs); free(bb); }
结果字符串的边界框是正确的.由于变音符号本身是一个字形,而字符是另一个字形意味着Ä由两个字形组成,因此变音符号存在问题.怎么可以使用它？
还有其他可能性我忽略了并值得尝试吗？
编辑
CTLineGetTypographicBounds的第三个选项似乎有效.然而,我正在运行一个不同的问题,即CATextLayer中的第一行缺少其变音符号.第一行不知何故不够高.这意味着我在这里咆哮错误的树.
