Add support for repeating-conic-gradient()

Add support for repeating-conic-gradient()

Since the underlying SkSweepGradient implementation doesn't support
repeating color stops, generate synthetic stops to cover the whole
unit interval.  Interpolate colors for 0 and 1 when stops are not coincident.

We can also remove the ConicGradient spread method ctor arg, as it serves no
purpose.

BUG=706973
Review-Url: https://codereview.chromium.org/2792163002
Cr-Commit-Position: refs/heads/master@{#462250}
Committed: https://chromium.googlesource.com/chromium/src/+/65a58f0cd7291f90e7edd10ea42c7c8de24f3d1a

[f(malita), 2017-04-04 18:35:52]

The CQ bit was checked by fmalita@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-04 18:36:23]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[f(malita), 2017-04-04 18:37:06]

The CQ bit was unchecked by fmalita@chromium.org

[f(malita), 2017-04-04 18:38:51]

The CQ bit was checked by fmalita@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-04 18:39:45]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[f(malita), 2017-04-04 18:46:44]

The CQ bit was checked by fmalita@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-04 18:47:50]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-04 20:51:04]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-04 20:51:06]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[f(malita), 2017-04-04 22:11:49]

The CQ bit was checked by fmalita@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-04 22:12:34]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-04 23:16:25]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-04 23:16:26]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[f(malita), 2017-04-05 14:18:20]

The CQ bit was checked by fmalita@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-05 14:18:38]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-05 16:21:53]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-05 16:21:54]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[f(malita), 2017-04-05 18:08:41]

The CQ bit was checked by fmalita@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-05 18:09:28]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-05 18:14:19]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-05 18:14:20]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[f(malita), 2017-04-05 18:16:58]

Description was changed from

==========
Add support for repeating-conic-gradient()

WIP

BUG=
==========

to

==========
Add support for repeating-conic-gradient()

Since the underlying SkSweepGradient implementation doesn't support
repeating color stops, generate synthetic stops to cover the whole
unit interval.  Interpolate colors for 0 and 1 when stops are not coincident.

We can also remove the ConicGradient spread method ctor arg, as it serves no
purpose.

BUG=706973
==========

[f(malita), 2017-04-05 18:16:58]

fmalita@chromium.org changed reviewers:
+ fs@opera.com, schenney@chromium.org

[f(malita), 2017-04-05 18:21:16]

Pending baselines, otherwise good to go.

[fs, 2017-04-05 19:19:57]

lgtm

https://codereview.chromium.org/2792163002/diff/140001/third_party/WebKit/Sou...
File third_party/WebKit/Source/core/css/CSSGradientValue.cpp (right):

https://codereview.chromium.org/2792163002/diff/140001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/css/CSSGradientValue.cpp:516: if (repeatSpan <
std::numeric_limits<float>::epsilon()) {
Should we be worried about small (greater than eps, but still small) values (=>
huge amounts of stops) here?

[f(malita), 2017-04-05 19:33:57]

https://codereview.chromium.org/2792163002/diff/140001/third_party/WebKit/Sou...
File third_party/WebKit/Source/core/css/CSSGradientValue.cpp (right):

https://codereview.chromium.org/2792163002/diff/140001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/css/CSSGradientValue.cpp:516: if (repeatSpan <
std::numeric_limits<float>::epsilon()) {
On 2017/04/05 19:19:57, fs wrote:
> Should we be worried about small (greater than eps, but still small) values
(=>
> huge amounts of stops) here?

Yup, that's not ideal.  The current Skia impl is using a 256 LUT (so it'll just
look ugly), but we're planning to switch to an analytical impl - then lots of
stops will slow things down.

But while we have the hood up, I think we could also add native sweep repeat to
Skia and then we can remove this kludge.

[fs, 2017-04-05 20:04:11]

https://codereview.chromium.org/2792163002/diff/140001/third_party/WebKit/Sou...
File third_party/WebKit/Source/core/css/CSSGradientValue.cpp (right):

https://codereview.chromium.org/2792163002/diff/140001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/css/CSSGradientValue.cpp:516: if (repeatSpan <
std::numeric_limits<float>::epsilon()) {
On 2017/04/05 at 19:33:57, f(malita) wrote:
> On 2017/04/05 19:19:57, fs wrote:
> > Should we be worried about small (greater than eps, but still small) values
(=>
> > huge amounts of stops) here?
> 
> Yup, that's not ideal.  The current Skia impl is using a 256 LUT (so it'll
just look ugly), but we're planning to switch to an analytical impl - then lots
of stops will slow things down.
> 
> But while we have the hood up, I think we could also add native sweep repeat
to Skia and then we can remove this kludge.

We're good then it sounds like.

[f(malita), 2017-04-05 21:00:48]

The CQ bit was checked by fmalita@chromium.org

[f(malita), 2017-04-05 21:00:48]

The patchset sent to the CQ was uploaded after l-g-t-m from fs@opera.com
Link to the patchset: https://codereview.chromium.org/2792163002/#ps160001
(title: "baselines")

[commit-bot: I haz the power, 2017-04-05 21:01:41]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-05 22:36:55]

CQ is committing da patch.

Bot data: {"patchset_id": 160001, "attempt_start_ts": 1491426048489040,
"parent_rev": "e749951e2d9689e61ba9b72ada59ab04166e4927", "commit_rev":
"65a58f0cd7291f90e7edd10ea42c7c8de24f3d1a"}

[commit-bot: I haz the power, 2017-04-05 22:37:43]

Description was changed from

==========
Add support for repeating-conic-gradient()

Since the underlying SkSweepGradient implementation doesn't support
repeating color stops, generate synthetic stops to cover the whole
unit interval.  Interpolate colors for 0 and 1 when stops are not coincident.

We can also remove the ConicGradient spread method ctor arg, as it serves no
purpose.

BUG=706973
==========

to

==========
Add support for repeating-conic-gradient()

Since the underlying SkSweepGradient implementation doesn't support
repeating color stops, generate synthetic stops to cover the whole
unit interval.  Interpolate colors for 0 and 1 when stops are not coincident.

We can also remove the ConicGradient spread method ctor arg, as it serves no
purpose.

BUG=706973

Review-Url: https://codereview.chromium.org/2792163002
Cr-Commit-Position: refs/heads/master@{#462250}
Committed:
https://chromium.googlesource.com/chromium/src/+/65a58f0cd7291f90e7edd10ea42c...
==========

[commit-bot: I haz the power, 2017-04-05 22:37:44]

Committed patchset #9 (id:160001) as
https://chromium.googlesource.com/chromium/src/+/65a58f0cd7291f90e7edd10ea42c...