Use SkBitmapProcStateAutoMapper for filter samplers also

Use SkBitmapProcStateAutoMapper for filter samplers also

Observation: filter procs are also biased by s.fFilterOne{X,Y} / 2.  They all do
something along these lines:

  s.fInvProc(s.fInvMatrix,
    SkIntToScalar(x) + SK_ScalarHalf,
    SkIntToScalar(y) + SK_ScalarHalf, &srcPt);

  SkFixed fx = SkScalarToFixed(srcPt.fX) - (s.fFilterOneX >> 1);
  SkFixed fy = SkScalarToFixed(srcPt.fY) - (s.fFilterOneX >> 1);

It's trivial to extend SkBitmapProcStateAutoMapper to handle this internally, and
convert everyone off explicit mapping.


R=reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1661613002
CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot

Committed: https://skia.googlesource.com/skia/+/2404f03413bc9b4fa3f556c64642e57507092d8d

[f(malita), 2016-02-02 20:09:09]

Description was changed from

==========
Use SkBitmapProcStateAutoMapper for filter samplers also


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

to

==========
Use SkBitmapProcStateAutoMapper for filter samplers also


BUG=skia:
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot
==========

[f(malita), 2016-02-02 21:15:39]

Description was changed from

==========
Use SkBitmapProcStateAutoMapper for filter samplers also


BUG=skia:
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot
==========

to

==========
Use SkBitmapProcStateAutoMapper for filter samplers also

Observation: filter procs are also biased by s.fFilterOne{X,Y} / 2.  They all do
something along these lines:

  s.fInvProc(s.fInvMatrix,
    SkIntToScalar(x) + SK_ScalarHalf,
    SkIntToScalar(y) + SK_ScalarHalf, &srcPt);

  SkFixed fx = SkScalarToFixed(srcPt.fX) - (s.fFilterOneX >> 1);
  SkFixed fy = SkScalarToFixed(srcPt.fY) - (s.fFilterOneX >> 1);

It's trivial to extend SkBitmapProcStateAutoMapper to handle this internally,
and
convert everyone off explicit mapping.


R=reed@google.com
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot
==========

[f(malita), 2016-02-02 21:15:39]

fmalita@chromium.org changed reviewers:
+ reed@google.com

[f(malita), 2016-02-02 21:28:09]

Worth cleaning up all fInvProc boilerplate?

Adds an extra conditional to SkBitmapProcStateAutoMapper, but I don't think
that's particularly perf sensitive.  If push comes to shove we could convert to
a template.

There are more GM diffs than I was hoping - but they're trivial, due to having
more precision in SkFractionalInt bias calculations:
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...

(I verified that forcing the bias arithmetic in SkFixed matches the prev GMs)

There's no good way to guard this change because some legacy paths mix
SkFractionalInt/SkFixed bias arithmetic.  Rather than polluting with a bunch of
guards, I'm planning to suppress layout tests manually if/when this lands.

[f(malita), 2016-02-02 21:29:32]

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

[commit-bot: I haz the power, 2016-02-02 21:29:51]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1661613002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1661613002/20001

[f(malita), 2016-02-02 21:34:11]

The CQ bit was unchecked by fmalita@chromium.org

[reed1, 2016-02-03 00:10:10]

lgtm

I wonder if the mapper's api should be

mapper.fractionalIntX()

in case someone forgets its type (since its slightly non-standard. Just a crazy
thought.

[f(malita), 2016-02-03 13:42:51]

On 2016/02/03 00:10:10, reed1 wrote:
> I wonder if the mapper's api should be
> 
> mapper.fractionalIntX()
> 
> in case someone forgets its type (since its slightly non-standard. Just a
crazy
> thought.

Sounds good, will do.

[f(malita), 2016-02-03 13:42:57]

The CQ bit was checked by fmalita@chromium.org

[commit-bot: I haz the power, 2016-02-03 13:43:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1661613002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1661613002/20001

[commit-bot: I haz the power, 2016-02-03 13:44:23]

Description was changed from

==========
Use SkBitmapProcStateAutoMapper for filter samplers also

Observation: filter procs are also biased by s.fFilterOne{X,Y} / 2.  They all do
something along these lines:

  s.fInvProc(s.fInvMatrix,
    SkIntToScalar(x) + SK_ScalarHalf,
    SkIntToScalar(y) + SK_ScalarHalf, &srcPt);

  SkFixed fx = SkScalarToFixed(srcPt.fX) - (s.fFilterOneX >> 1);
  SkFixed fy = SkScalarToFixed(srcPt.fY) - (s.fFilterOneX >> 1);

It's trivial to extend SkBitmapProcStateAutoMapper to handle this internally,
and
convert everyone off explicit mapping.


R=reed@google.com
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot
==========

to

==========
Use SkBitmapProcStateAutoMapper for filter samplers also

Observation: filter procs are also biased by s.fFilterOne{X,Y} / 2.  They all do
something along these lines:

  s.fInvProc(s.fInvMatrix,
    SkIntToScalar(x) + SK_ScalarHalf,
    SkIntToScalar(y) + SK_ScalarHalf, &srcPt);

  SkFixed fx = SkScalarToFixed(srcPt.fX) - (s.fFilterOneX >> 1);
  SkFixed fy = SkScalarToFixed(srcPt.fY) - (s.fFilterOneX >> 1);

It's trivial to extend SkBitmapProcStateAutoMapper to handle this internally,
and
convert everyone off explicit mapping.


R=reed@google.com
GOLD_TRYBOT_URL=
https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&is...
CQ_EXTRA_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot

Committed:
https://skia.googlesource.com/skia/+/2404f03413bc9b4fa3f556c64642e57507092d8d
==========

[commit-bot: I haz the power, 2016-02-03 13:44:24]

Committed patchset #2 (id:20001) as
https://skia.googlesource.com/skia/+/2404f03413bc9b4fa3f556c64642e57507092d8d