本文介绍利用BezierPath, 通过CoreText重新绘制文字的方向.

具体操作 简单介绍如下

文字显示的方向

typedef NS_ENUM(NSUInteger, TransformLayerDirectionType) {
    TransformLayerDirectionUp = 0, //文字方向朝上(默认正常)
    TransformLayerDirectionLeft,//文字方向朝左
    TransformLayerDirectionDown,//文字方向朝下
    TransformLayerDirectionRight//文字方向朝右
};

根据传进来的属性, 设置Path的属性

CTFontRef ctFont = CTFontCreateWithName((__bridge CFStringRef)font.fontName, font.pointSize, NULL);
    
    if (!ctFont) return nil;
    
    NSDictionary *attrs = @{ (__bridge id)kCTFontAttributeName:(__bridge id)ctFont };
    
    NSAttributedString *attrString = [[NSAttributedString alloc] initWithString:text attributes:attrs];

获取行数组

CFArrayRef runs = CTLineGetGlyphRuns(line);

循环遍历 绘制单行 确定位置

for (CFIndex iRun = 0, iRunMax = CFArrayGetCount(runs); iRun < iRunMax; iRun++) {
        
        CTRunRef run = (CTRunRef)CFArrayGetValueAtIndex(runs, iRun);
        
        CTFontRef runFont = CFDictionaryGetValue(CTRunGetAttributes(run), kCTFontAttributeName);
        
        for (CFIndex iGlyph = 0, iGlyphMax = CTRunGetGlyphCount(run); iGlyph < iGlyphMax; iGlyph++) {
            
            CFRange glyphRange = CFRangeMake(iGlyph, 1);
            
            CGGlyph glyph;
            
            CGPoint position;
            
            CTRunGetGlyphs(run, glyphRange, &glyph);
            
            CTRunGetPositions(run, glyphRange, &position);
            
            CGPathRef glyphPath = CTFontCreatePathForGlyph(runFont, glyph, NULL);
         
        }
    }

旋转每行中单独的字

if (glyphPath) {
                
                CGAffineTransform transform1 = CGAffineTransformMakeRotation(M_PI*textDirection*0.5);
                
                CGAffineTransform transform2 =  CGAffineTransformMakeTranslation(position.x, position.y);
                
                CGAffineTransform transform = CGAffineTransformConcat(transform1, transform2);
                
                CGPathAddPath(cgPath, &transform, glyphPath);
                
                CGPathRelease(glyphPath);
            }

根据路径创建layer 设置属性

 // 创建文字路径
    UIBezierPath *path;
    path = [UIBezierPath bezierPathWithText:self font:aFont andWithDirection:directionStr];
    
    // 创建路径图层
    CAShapeLayer *pathLayer = [CAShapeLayer layer];
    pathLayer.frame = aRect;
    pathLayer.bounds = CGPathGetBoundingBox(path.CGPath);
    pathLayer.geometryFlipped = NO;
    pathLayer.path = path.CGPath;
    pathLayer.strokeColor = [aColor CGColor];
    pathLayer.fillColor = [aColor CGColor];
    pathLayer.lineWidth = 1.0f;
    pathLayer.lineJoin = kCALineJoinBevel;
    [aView.layer addSublayer:pathLayer];

调用

_shapeLayer = [_contentLabel.text animateOnView:_contentLabel atRect:_contentLabel.bounds forFont:_contentLabel.font withColor:_contentLabel.textColor andDuration:0.0 andWithIsNeedAnimation:false andDirection:TransformLayerDirectionUp];
    [_contentLabel.layer addSublayer:_shapeLayer];

效果如下

• 文字方向朝上(默认状态)

  
  文字方向朝上.png

• 文字方向朝下

  
  文字方向朝下.png

• 文字方向朝左

  
  文字方向朝左.png
• 文字方向朝右

文字方向朝右.png

代码路径:代码传送门