Re: [webkit-dev] How to deal with 1-pixel differences in reftests ?

2015-11-30 Thread Myles C. Maxfield
I believe that any way to specify fuzziness should not treat the following cases the same: - 1 pixel being 100% wrong - All pixels being 1% wrong There are certain cases where one of those should cause a failure, but the other shouldn't. --Myles > On Nov 18, 2015, at 10:44 PM, Alexey

Re: [webkit-dev] How to deal with 1-pixel differences in reftests ?

2015-11-18 Thread Darin Adler
> On Nov 18, 2015, at 4:36 AM, Carlos Alberto Lopez Perez > wrote: > > Some reference tests give a 1-pixel or very few pixel differences [1]. Why? We need to understand why. > Should we tolerate a few pixel differences for reftests ? I don’t think we should. I think we

Re: [webkit-dev] How to deal with 1-pixel differences in reftests ?

2015-11-18 Thread Alexey Proskuryakov
Hi, I do not think that there is a way to algorithmically define what an acceptable difference is. Here are a few cases where it's critical to detect small differences: - color management, e.g. testing different code paths that should match precisely; - finding uninitialized memory use bugs

Re: [webkit-dev] How to deal with 1-pixel differences in reftests ?

2015-11-18 Thread Simon Fraser
> On Nov 18, 2015, at 9:04 AM, Darin Adler wrote: > >> On Nov 18, 2015, at 4:36 AM, Carlos Alberto Lopez Perez >> wrote: >> >> Some reference tests give a 1-pixel or very few pixel differences [1]. > > Why? We need to understand why. > >> Should we

[webkit-dev] How to deal with 1-pixel differences in reftests ?

2015-11-18 Thread Carlos Alberto Lopez Perez
Hi, Some reference tests give a 1-pixel or very few pixel differences [1]. I'm not sure if this really indicates a problem in the WebKit code, or it indicates that we are just too strict not allowing even a very small percentage in pixel differences for this kind of tests. Should we tolerate a

Re: [webkit-dev] How to deal with 1-pixel differences in reftests ?

2015-11-18 Thread Alexey Proskuryakov
> 18 нояб. 2015 г., в 11:50, Simon Fraser написал(а): > > There are some well-understood reasons why a test might not exactly match its > reference. One is that the test uses compositing layers to do clipping, but > the reference just clips with drawing, and these are