always compute a cubic normal

always compute a cubic tangent

If the inflection of a cubic is also the cusp, the tangent
is degenerate at that t when computed directly. Rather than
giving up, subdivide the curve there and use the computed
control points to compute the tangent.

This strategy also removes the error paths where the tangent
formerly could not be computed.

R=reed@google.com
BUG=615686
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2020293002

Committed: https://skia.googlesource.com/skia/+/ba150cc283301a28693a18d4aa9d14b1a1616ab3

[caryclark, 2016-05-31 14:43:40]

Description was changed from

==========
always compute a cubic tangent

If the inflection of a cubic is also the cusp, the tangent
is degenerate at that t when computed directly. Rather than
giving up, subdivide the curve there and use the computed
control points to compute the tangent.

This strategy also removes the error paths where the tangent
formerly could not be computed.

R=reed@google.com
BUG=615686
==========

to

==========
always compute a cubic tangent

If the inflection of a cubic is also the cusp, the tangent
is degenerate at that t when computed directly. Rather than
giving up, subdivide the curve there and use the computed
control points to compute the tangent.

This strategy also removes the error paths where the tangent
formerly could not be computed.

R=reed@google.com
BUG=615686
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2020293002
==========

[caryclark, 2016-05-31 14:44:07]

The CQ bit was checked by caryclark@google.com to run a CQ dry run

[commit-bot: I haz the power, 2016-05-31 14:44:14]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2020293002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2020293002/1

[commit-bot: I haz the power, 2016-05-31 15:00:44]

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

[commit-bot: I haz the power, 2016-05-31 15:00:45]

Dry run: This issue passed the CQ dry run.

[reed1, 2016-05-31 22:10:54]

lgtm

[caryclark, 2016-06-01 11:40:58]

The CQ bit was checked by caryclark@google.com

[commit-bot: I haz the power, 2016-06-01 11:41:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2020293002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2020293002/1

[commit-bot: I haz the power, 2016-06-01 11:42:05]

Description was changed from

==========
always compute a cubic tangent

If the inflection of a cubic is also the cusp, the tangent
is degenerate at that t when computed directly. Rather than
giving up, subdivide the curve there and use the computed
control points to compute the tangent.

This strategy also removes the error paths where the tangent
formerly could not be computed.

R=reed@google.com
BUG=615686
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2020293002
==========

to

==========
always compute a cubic tangent

If the inflection of a cubic is also the cusp, the tangent
is degenerate at that t when computed directly. Rather than
giving up, subdivide the curve there and use the computed
control points to compute the tangent.

This strategy also removes the error paths where the tangent
formerly could not be computed.

R=reed@google.com
BUG=615686
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2020293002

Committed:
https://skia.googlesource.com/skia/+/ba150cc283301a28693a18d4aa9d14b1a1616ab3
==========

[commit-bot: I haz the power, 2016-06-01 11:42:06]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/ba150cc283301a28693a18d4aa9d14b1a1616ab3