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Issue 1227 Hairline rendering may touch the same pixel twice
Starred by 5 users Project Member Reported by schenney@chromium.org, Apr 11 2013 Back to list
Status: Unconfirmed
Owner:
Cc:
Area: ----
Priority: Low
Type: Performance



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This was found when debugging https://code.google.com/p/chromium/issues/detail?id=111470, which was an example of a cubic curve of width less than a pixel.

1. Implement/setup you favorite way to detect when pixels are blended due to a hairline curve (I have forgotten the method that I instrumented) 
2. Track which x,y locations are written while painting the curve
3. Note that almost all pixels are touched twice, and the last pixel is touched 4 times.

Ideally, each pixel would be touched just once for a single curve.

This effect may only have been seen due to the cubic being broken down into 1-pixel length lines, or maybe even smaller lines that resulted in two 1-pixel lines in the same spot after rounding. I'm not sure.

 
Project Member Comment 1 by hcm@google.com, Sep 15 2014
Labels: -Type-Defect Type-Performance
Project Member Comment 2 by reed@chromium.org, Oct 9 2014
Labels: -Priority-Medium Priority-Low
Project Member Comment 3 by hcm@google.com, Dec 7 2015
Labels: Hotlist-Fixit
Project Member Comment 4 by caryclark@google.com, Feb 26 2016
Status: Unconfirmed
This very well may be fixed. Please add example data if you see anything like the description (last pixel touched 4 times) again. Thanks
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