861805 - Stop layers from snapping transforms for SVG content

Status: RESOLVED DUPLICATE of bug 1523343

(Core :: SVG, defect)

Description

[Jonathan Watt [:jwatt]]

The layers code sometimes snaps transforms to keep things on pixel boundaries. While we want that for HTML, we don't want it for SVG.

Comment 1

[Jonathan Watt [:jwatt]]

Attachment: patch

Comment 2

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 737432 [details] [diff] [review]
patch

Review of attachment 737432 [details] [diff] [review]:
-----------------------------------------------------------------

::: gfx/layers/Layers.h
@@ +873,5 @@
> +   * CONSTRUCTION PHASE ONLY
> +   * Used for SVG content which does not want the snapping behavior that is
> +   * desirable in HTML.
> +   */
> +  void DisableTransformSnapping();

I'd prefer to make this a CONTENT_ flag. Say CONTENT_DISABLE_TRANSFORM_SNAPPING.

Comment 3

[Jonathan Watt [:jwatt]]

Attachment: patch

(In reply to Robert O'Callahan (:roc) (Mozilla Corporation) from comment #2)
> I'd prefer to make this a CONTENT_ flag. Say
> CONTENT_DISABLE_TRANSFORM_SNAPPING.

Sure, sounds good.

Comment 4

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 737444 [details] [diff] [review]
patch

Review of attachment 737444 [details] [diff] [review]:
-----------------------------------------------------------------

::: gfx/layers/Layers.h
@@ +665,5 @@
>    }
> +  void AddContentFlags(uint32_t aFlags)
> +  {
> +    SetContentFlags(mContentFlags | aFlags);
> +  }

You don't need this...

::: layout/base/FrameLayerBuilder.cpp
@@ +2946,5 @@
>    containerLayer->SetUserData(&gNotifySubDocInvalidationData, nullptr);
>  
> +  if (aContainerFrame->GetStateBits() & NS_FRAME_SVG_LAYOUT) {
> +    containerLayer->AddContentFlags(Layer::CONTENT_DISABLE_TRANSFORM_SNAPPING);
> +  }

Just fold this into the SetContentFlags call above.

Comment 5

[Jonathan Watt [:jwatt]]

Attachment: patch

Comment 6

[Jonathan Watt [:jwatt]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/644f16c3f87c

Thanks!

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/644f16c3f87c

Comment 8

[Robert O'Callahan (:roc) (email my personal email if necessary)]

We should back this out for bug 871729.

Comment 9

[Matt Woodrow (:mattwoodrow)]

Backed out as https://hg.mozilla.org/integration/mozilla-inbound/rev/854310083421 for causing bug 871729.

This change didn't appear to change/fix any reftests, but it did cause a visible regression on a real world site.

It's not clear what this change was meant to fix either. We should discuss this again once jwatt returns from PTO.

Comment 10

[Ed Morley [:emorley]]

Merge of backout:
https://hg.mozilla.org/mozilla-central/rev/854310083421

Comment 11

[Jonathan Watt [:jwatt]]

Maybe another source of pixel snapping:

http://hg.mozilla.org/mozilla-central/rev/23ee0b1ce250#l6.2

Comment 12

[Jonathan Watt [:jwatt]]

Another example of the snapping sucking is the horizontal animation in:

http://jeremie.patonnier.net/experiences/parisweb2011/animation.svg