Unexpected LineJoinStyle behavior when lines in path at 180 degrees

Originator:deep108
Number:rdar://12723863 Date Originated:16-Nov-2012
Status:Closed Resolved:Fixed in iOS 7
Product:iPad SDK Product Version:6.01
Classification:UI/Usability Reproducible:always
 
Summary:
I'm getting a clipped LineJoin in a UIBezierPath when one line comes back exactly over the previous line. If I adjust the second line by one pixel, the LineJoin behaves as expected.

Steps to Reproduce:
UIBezierPath *path = [UIBezierPath bezierPath];
[path setLineWidth:10.0f];
[path setLineCapStyle:kCGLineCapRound];
[path setLineJoinStyle:kCGLineJoinRound];
[path moveToPoint:CGPointMake(100, 100)];
[path addLineToPoint:CGPointMake(200, 100)];
[path addLineToPoint:CGPointMake(150, 100)];
[path moveToPoint:CGPointMake(100, 120)];
[path addLineToPoint:CGPointMake(200, 120)];
[path addLineToPoint:CGPointMake(150, 121)];
[[UIColor redColor] setStroke];
[path stroke];

Expected Results:
Both lines should have a rounded ends on both sides.

Actual Results:
The first line has a flat end on the right side.  The second line looks as expected.

Regression:

Notes:
I have included a screenshot of the output from the code sample.

Output:
https://www.dropbox.com/s/8ew1a8ysyjluf2w/LineJoinTest.jpg

Comments


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