1756175 - Implement roundRect for canvas2D

Status: RESOLVED FIXED

(Core :: Graphics: Canvas2D, enhancement, P5)

Description

[aaronhk]

Steps to reproduce:

Original proposal: https://github.com/fserb/canvas2D/blob/master/spec/roundrect.md

Spec: https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-roundrect

Recent spec change: https://github.com/whatwg/html/pull/7621#event-6093663928

Comment 1

[Andrew Osmond [:aosmond] (he/him)]

Do you think we need to prioritize this?

Comment 2

[Lee Salzman [:lsalzman]]

If it is in the spec and someone wants to go ahead and implement it, I don't see why not, but unless it's a webcompat issue I don't know that it's a distinct priority yet?

Comment 3

[Deebash D]

Can I work on it?

Comment 4

[Deebash D]

Can I work on this?

Comment 5

[Lee Salzman [:lsalzman]]

(In reply to Deebash D from comment #4)

Can I work on this?

Anyone is welcome to contribute to Mozilla, if they feel they're up to it. If it is your first time contributing code to Mozilla, reviewing https://firefox-source-docs.mozilla.org/setup/contributing_code.html is probably of use.

Comment 6

[Tom S [:evilpie]]

Attachment: Bug 1756175 - Implement roundRect for canvas2D. r?lsalzman

Comment 7

[Tom S [:evilpie]]

I implemented parts of this, but I probably won't be able to finish this without some help.

• Bug 1814235 means the current WebIDL as specified doesn't work
• I don't understand how to support mDSPathBuilder, which seems to require transforming everything?
• The CanvasPath implementation is missing, but hopefully we can just re-use most of the CanvasRenderingContext2D implementation for that.

Comment 8

[Tom S [:evilpie]]

Hi Andrew! Maybe you could give me some hints? See comment 7, especially point two and three.

Comment 9

[Peter Van der Beken [:peterv]]

(In reply to Tom S [:evilpie] from comment #7)

• Bug 1814235 means the current WebIDL as specified doesn't work

I landed a fix for this, it should work now. Let me know if you run into any other issues!

Comment 10

[Tom S [:evilpie]]

Thank you Peter! We are now down to only two failures in the WPT html/canvas/element/path-objects/ test suite, those might be related to the scaling that is supposed to be done in Step 11? The two other questions, particular about mDSPathBuilder remain.

/html/canvas/element/path-objects/2d.path.roundrect.radius.intersecting.1.html
  FAIL Check that roundRects with intersecting corner arcs are rendered correctly. - assert_equals: Red channel of the pixel at (2, 25) expected 0 but got 63
/html/canvas/element/path-objects/2d.path.roundrect.radius.intersecting.2.html
  FAIL Check that roundRects with intersecting corner arcs are rendered correctly. - assert_equals: Red channel of the pixel at (1, 1) expected 255 but got 0

Comment 11

[Tom S [:evilpie]]

Thanks everyone for your hints, we are only with those two failures in comment 10 left now.

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/154b792529c2
Implement roundRect for canvas2D. r=lsalzman,emilio

Comment 13

[Cristina Horotan [:chorotan]]

https://hg.mozilla.org/mozilla-central/rev/154b792529c2

Comment 14

[Hamish Willee]

FF112 MDN docs work for this can be tracked in https://github.com/mdn/content/issues/25359.
Essentially this is just an MDN release note and browser compatibility data update, since this API is documented.