interpolation of coincidence must be local to a single span

interpolation of coincidence must be local to a single span

Pathops makes up intersections that it doesn't detect directly,
but do exist. For instance, if a is coincident with b, and
b is coincident with c, then for where they overlap
a is coincident with c.

The intersections are made up in different ways. In a few
places, the t values that are detected are interpolated to
guess the t values that represent invented intersections.

The interpolated t is not necessarily linear, but a linear
guess is good enough if the invented t lies between known
t values.

Additionally, improve debugging.

This passes the extended release test suite and additionally
passes the first 17 levels in the tiger test suite; 
previously, path ops passed 7 levels.

The tiger suite is composed of 37 levels in increasing
complexity, described by about 300K tests.

TBR=reed@google.com
BUG=skia:5131
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2300203002

Committed: https://skia.googlesource.com/skia/+/8016b264ceec2b11d2acbeb77a9fbe66e48368b9

[caryclark, 2016-09-01 21:25:04]

Description was changed from

==========
wip; interpolation of coincidence must be local to a single span

BUG=skia:
==========

to

==========
wip; interpolation of coincidence must be local to a single span

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2300203002
==========

[caryclark, 2016-09-02 14:45:02]

Description was changed from

==========
wip; interpolation of coincidence must be local to a single span

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2300203002
==========

to

==========
interpolation of coincidence must be local to a single span

Pathops makes up intersections that it doesn't detect directly,
but do exist. For instance, if a is coincident with b, and
b is coincident with c, then for where they overlap
a is coincident with c.

The intersections are made up in different ways. In a few
places, the t values that are detected are interpolated to
guess the t values that represent invented intersections.

The interpolated t is not necessarily linear, but a linear
guess is good enough if the invented t lies between known
t values.

Additionally, improve debugging.

This passes the extended release test suite and additionally
passes the first 17 levels in the tiger test suite; 
previously, path ops passed 7 levels.

The tiger suite is composed of 37 levels in increasing
complexity, described by about 300K tests.

TBR=reed@google.com
BUG=skia:5131
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2300203002
==========

[caryclark, 2016-09-02 14:45:03]

caryclark@google.com changed reviewers:
+ reed@google.com

[caryclark, 2016-09-02 18:42:28]

The CQ bit was checked by caryclark@google.com

[commit-bot: I haz the power, 2016-09-02 18:42:36]

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, 2016-09-02 18:45:46]

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

[commit-bot: I haz the power, 2016-09-02 18:45:49]

Try jobs failed on following builders:
  Test-Ubuntu-GCC-ShuttleA-GPU-GTX660-x86_64-Release-GN-Trybot on
master.client.skia (JOB_FAILED,
http://build.chromium.org/p/client.skia/builders/Test-Ubuntu-GCC-ShuttleA-GPU...)

[caryclark, 2016-09-02 18:52:52]

The CQ bit was checked by caryclark@google.com

[commit-bot: I haz the power, 2016-09-02 18:52:56]

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, 2016-09-02 18:55:26]

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

[commit-bot: I haz the power, 2016-09-02 18:55:27]

Try jobs failed on following builders:
  Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-Shared-Trybot on
master.client.skia (JOB_FAILED,
http://build.chromium.org/p/client.skia/builders/Test-Ubuntu-GCC-GCE-CPU-AVX2...)

[caryclark, 2016-09-02 18:58:15]

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

[commit-bot: I haz the power, 2016-09-02 18:58:26]

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, 2016-09-02 19:24:26]

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

[commit-bot: I haz the power, 2016-09-02 19:24:27]

Dry run: This issue passed the CQ dry run.

[reed1, 2016-09-04 17:18:27]

I don't understand enough of the context to actually understand the CL, but it
is readable and has lots of extra asserts, so LGTM

[caryclark, 2016-09-06 12:24:33]

The CQ bit was checked by caryclark@google.com

[commit-bot: I haz the power, 2016-09-06 12:24:44]

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, 2016-09-06 12:59:49]

Description was changed from

==========
interpolation of coincidence must be local to a single span

Pathops makes up intersections that it doesn't detect directly,
but do exist. For instance, if a is coincident with b, and
b is coincident with c, then for where they overlap
a is coincident with c.

The intersections are made up in different ways. In a few
places, the t values that are detected are interpolated to
guess the t values that represent invented intersections.

The interpolated t is not necessarily linear, but a linear
guess is good enough if the invented t lies between known
t values.

Additionally, improve debugging.

This passes the extended release test suite and additionally
passes the first 17 levels in the tiger test suite; 
previously, path ops passed 7 levels.

The tiger suite is composed of 37 levels in increasing
complexity, described by about 300K tests.

TBR=reed@google.com
BUG=skia:5131
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2300203002
==========

to

==========
interpolation of coincidence must be local to a single span

Pathops makes up intersections that it doesn't detect directly,
but do exist. For instance, if a is coincident with b, and
b is coincident with c, then for where they overlap
a is coincident with c.

The intersections are made up in different ways. In a few
places, the t values that are detected are interpolated to
guess the t values that represent invented intersections.

The interpolated t is not necessarily linear, but a linear
guess is good enough if the invented t lies between known
t values.

Additionally, improve debugging.

This passes the extended release test suite and additionally
passes the first 17 levels in the tiger test suite; 
previously, path ops passed 7 levels.

The tiger suite is composed of 37 levels in increasing
complexity, described by about 300K tests.

TBR=reed@google.com
BUG=skia:5131
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2300203002

Committed:
https://skia.googlesource.com/skia/+/8016b264ceec2b11d2acbeb77a9fbe66e48368b9
==========

[commit-bot: I haz the power, 2016-09-06 12:59:50]

Committed patchset #4 (id:60001) as
https://skia.googlesource.com/skia/+/8016b264ceec2b11d2acbeb77a9fbe66e48368b9