4f gradient negative-dx interval fixup for kMirror_TileMode

4f gradient negative-dx interval fixup for kMirror_TileMode

4f intervals are meant to be monotonically increasing in X.  This means
we invert the point order when dx < 0:

  [0...1) -> (1...0]

For kMirror_TileMode, we also append a duplicate/flipped interval
sequence and expand the range to 2:

  [0...1) -> [0...1)[1...2)

When dx < 0, the current logic yields

  (1...0] -> (1...0](2...1]

which violates the interval monotonicity.

To achieve the proper order, we need to swap the two halves:

  (1...0] -> (1...0](2...1] -> (2...1](1...0]

R=reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1735773003

Committed: https://skia.googlesource.com/skia/+/b976b2761f0bb651edb1e7fe3becc1889cfe3fc4

[f(malita), 2016-02-25 20:43:48]

Description was changed from

==========
4f gradient negative-dx interval fixup for kMirror_TileMode

4f intervals are meant to be monotonically increasing in X.  This means
we invert the order when dx < 0:

  [0...1) -> (1...0]

For kMirror_TileMode, we also append a duplicate/flipped interval
sequence and expand the range to 2:

  [0...1) -> [0...1)[1...2)

When d < 0x, the current logic yields

  (1...0] -> (1...0](2...1]

which violates the interval monotonicity.

To achieve the proper order, we need to swap the two halves:

  (1...0] -> (1...0](2...1] -> (2...1](1...0]

R=reed@google.com
==========

to

==========
4f gradient negative-dx interval fixup for kMirror_TileMode

4f intervals are meant to be monotonically increasing in X.  This means
we invert the order when dx < 0:

  [0...1) -> (1...0]

For kMirror_TileMode, we also append a duplicate/flipped interval
sequence and expand the range to 2:

  [0...1) -> [0...1)[1...2)

When d < 0x, the current logic yields

  (1...0] -> (1...0](2...1]

which violates the interval monotonicity.

To achieve the proper order, we need to swap the two halves:

  (1...0] -> (1...0](2...1] -> (2...1](1...0]

R=reed@google.com
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

[f(malita), 2016-02-25 20:44:23]

Description was changed from

==========
4f gradient negative-dx interval fixup for kMirror_TileMode

4f intervals are meant to be monotonically increasing in X.  This means
we invert the order when dx < 0:

  [0...1) -> (1...0]

For kMirror_TileMode, we also append a duplicate/flipped interval
sequence and expand the range to 2:

  [0...1) -> [0...1)[1...2)

When d < 0x, the current logic yields

  (1...0] -> (1...0](2...1]

which violates the interval monotonicity.

To achieve the proper order, we need to swap the two halves:

  (1...0] -> (1...0](2...1] -> (2...1](1...0]

R=reed@google.com
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

to

==========
4f gradient negative-dx interval fixup for kMirror_TileMode

4f intervals are meant to be monotonically increasing in X.  This means
we invert the point order when dx < 0:

  [0...1) -> (1...0]

For kMirror_TileMode, we also append a duplicate/flipped interval
sequence and expand the range to 2:

  [0...1) -> [0...1)[1...2)

When d < 0x, the current logic yields

  (1...0] -> (1...0](2...1]

which violates the interval monotonicity.

To achieve the proper order, we need to swap the two halves:

  (1...0] -> (1...0](2...1] -> (2...1](1...0]

R=reed@google.com
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

[f(malita), 2016-02-25 20:45:03]

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

[commit-bot: I haz the power, 2016-02-25 20:45:05]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1735773003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1735773003/1

[f(malita), 2016-02-25 20:48:42]

Description was changed from

==========
4f gradient negative-dx interval fixup for kMirror_TileMode

4f intervals are meant to be monotonically increasing in X.  This means
we invert the point order when dx < 0:

  [0...1) -> (1...0]

For kMirror_TileMode, we also append a duplicate/flipped interval
sequence and expand the range to 2:

  [0...1) -> [0...1)[1...2)

When d < 0x, the current logic yields

  (1...0] -> (1...0](2...1]

which violates the interval monotonicity.

To achieve the proper order, we need to swap the two halves:

  (1...0] -> (1...0](2...1] -> (2...1](1...0]

R=reed@google.com
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

to

==========
4f gradient negative-dx interval fixup for kMirror_TileMode

4f intervals are meant to be monotonically increasing in X.  This means
we invert the point order when dx < 0:

  [0...1) -> (1...0]

For kMirror_TileMode, we also append a duplicate/flipped interval
sequence and expand the range to 2:

  [0...1) -> [0...1)[1...2)

When dx < 0, the current logic yields

  (1...0] -> (1...0](2...1]

which violates the interval monotonicity.

To achieve the proper order, we need to swap the two halves:

  (1...0] -> (1...0](2...1] -> (2...1](1...0]

R=reed@google.com
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

[commit-bot: I haz the power, 2016-02-25 21:03:04]

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

[commit-bot: I haz the power, 2016-02-25 21:03:05]

Dry run: This issue passed the CQ dry run.

[f(malita), 2016-02-25 21:23:12]

The CQ bit was checked by fmalita@chromium.org

[commit-bot: I haz the power, 2016-02-25 21:23:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1735773003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1735773003/1

[commit-bot: I haz the power, 2016-02-25 21:23:22]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from valid reviewer(s) till 2016-02-26 03:23 UTC

[reed1, 2016-02-25 21:36:16]

lgtm

[commit-bot: I haz the power, 2016-02-25 21:37:30]

Description was changed from

==========
4f gradient negative-dx interval fixup for kMirror_TileMode

4f intervals are meant to be monotonically increasing in X.  This means
we invert the point order when dx < 0:

  [0...1) -> (1...0]

For kMirror_TileMode, we also append a duplicate/flipped interval
sequence and expand the range to 2:

  [0...1) -> [0...1)[1...2)

When dx < 0, the current logic yields

  (1...0] -> (1...0](2...1]

which violates the interval monotonicity.

To achieve the proper order, we need to swap the two halves:

  (1...0] -> (1...0](2...1] -> (2...1](1...0]

R=reed@google.com
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
==========

to

==========
4f gradient negative-dx interval fixup for kMirror_TileMode

4f intervals are meant to be monotonically increasing in X.  This means
we invert the point order when dx < 0:

  [0...1) -> (1...0]

For kMirror_TileMode, we also append a duplicate/flipped interval
sequence and expand the range to 2:

  [0...1) -> [0...1)[1...2)

When dx < 0, the current logic yields

  (1...0] -> (1...0](2...1]

which violates the interval monotonicity.

To achieve the proper order, we need to swap the two halves:

  (1...0] -> (1...0](2...1] -> (2...1](1...0]

R=reed@google.com
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...

Committed:
https://skia.googlesource.com/skia/+/b976b2761f0bb651edb1e7fe3becc1889cfe3fc4
==========

[commit-bot: I haz the power, 2016-02-25 21:37:30]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/b976b2761f0bb651edb1e7fe3becc1889cfe3fc4