fix line-pattern sampling from outside icon tex coords

[mollymerp]

fixes #5978

not sure if we should repeat the pattern instead of stretching 💭

test on master:

this branch:

updated with render test after d78d242

Launch Checklist

• briefly describe the changes in this PR
• write tests for all new functionality
• document any changes to public APIs
• post benchmark scores
• manually test the debug page

[mollymerp]

hmm whoops – this is not the correct fix. it is flipping the icon, and (flipping was existing behavior) not stretching the whole pattern (duh 🤦‍♀️ )

[mollymerp]

Ok, I think the fix is correct now. Added some explanatory comments as well.

[jfirebaugh]

Deferring to @ansis here.

[ansis]

Hmm, another option besides repeating and stretching would be just to draw nothing in the extra space. So if you have a 24px pattern and a 36px wide line it would look the same as a 24px pattern and 24px line.

I'm not sure which would be preferable, I guess it depends on the pattern?

[mollymerp]

mm good point. @aparlato @nickidlugash any opinions on desired behavior for line patterns with width > pattern height?

[aparlato]

mm good point. @aparlato @nickidlugash any opinions on desired behavior for line patterns with width > pattern height?

Oy this is a tough call. I'm inclined to say stretching meets more needs overall? The instances that I have used this property, this was the behavior I wanted. Although, @mollymerp, it looks like this only stretches it by width rather than treating the whole icon as larger. What's the reason behind just stretching by width rather than maintaining aspect ratio?

Hmm, another option besides repeating and stretching would be just to draw nothing in the extra space. So if you have a 24px pattern and a 36px wide line it would look the same as a 24px pattern and 24px line.

@ansis I think this makes sense in many cases, but since this can also be accomplished by just maintaining a 24px line, I think from a styling perspective this is less flexible unless I've misunderstood the comment.

[ansis]

Oy this is a tough call. I'm inclined to say stretching meets more needs overall?

Sounds good, let's do this.

it looks like this only stretches it by width rather than treating the whole icon as larger. What's the reason behind just stretching by width rather than maintaining aspect ratio?

Scaling horizontally is a bit problematic. If the pattern is scaled at anything other than the rate the line is scaled at then the pattern will look like it is sliding along the line.

@ansis I think this makes sense in many cases, but since this can also be accomplished by just maintaining a 24px line, I think from a styling perspective this is less flexible unless I've misunderstood the comment.

Yep, that's a good point.

[ansis]

Looks good!

[ansis]

good catch