Add new module for distance field generation.

Add new module for distance field generation.

This improves the speed over the previous method by 10x+, and makes using distance fields practical.

BUG=skia:2173
Committed: http://code.google.com/p/skia/source/detail?r=13729

Committed: http://code.google.com/p/skia/source/detail?r=13740

[robertphillips, 2014-03-10 15:48:10]

drive by nits

https://codereview.chromium.org/178543007/diff/130001/gm/gmmain.cpp
File gm/gmmain.cpp (right):

https://codereview.chromium.org/178543007/diff/130001/gm/gmmain.cpp#newcode2416
gm/gmmain.cpp:2416: if ((kGPU_Backend == config.fBackend)) {
extra space somewhere?

https://codereview.chromium.org/178543007/diff/130001/src/core/SkDistanceFiel...
File src/core/SkDistanceFieldGen.cpp (right):

https://codereview.chromium.org/178543007/diff/130001/src/core/SkDistanceFiel...
src/core/SkDistanceFieldGen.cpp:1: /*
2014?

[bsalomon, 2014-03-10 17:58:39]

lgtm

https://codereview.chromium.org/178543007/diff/150001/src/core/SkDistanceFiel...
File src/core/SkDistanceFieldGen.cpp (right):

https://codereview.chromium.org/178543007/diff/150001/src/core/SkDistanceFiel...
src/core/SkDistanceFieldGen.cpp:77: float temp = dx;
feel free to ignore, but there is SkTSwap

https://codereview.chromium.org/178543007/diff/150001/src/core/SkDistanceFiel...
File src/core/SkDistanceFieldGen.h (right):

https://codereview.chromium.org/178543007/diff/150001/src/core/SkDistanceFiel...
src/core/SkDistanceFieldGen.h:10: // this assumes the client has already
allocated the necessary space in distanceField
It seems like this could use some more descriptive comments.

https://codereview.chromium.org/178543007/diff/150001/src/gpu/GrTextStrike.cpp
File src/gpu/GrTextStrike.cpp (right):

https://codereview.chromium.org/178543007/diff/150001/src/gpu/GrTextStrike.cp...
src/gpu/GrTextStrike.cpp:324: sk_bzero(dfStorage.get(), dfSize);
We get here with color fonts (i.e. fUseDistanceField can be true)?

[jvanverth1, 2014-03-10 18:16:21]

https://codereview.chromium.org/178543007/diff/150001/src/gpu/GrTextStrike.cpp
File src/gpu/GrTextStrike.cpp (right):

https://codereview.chromium.org/178543007/diff/150001/src/gpu/GrTextStrike.cp...
src/gpu/GrTextStrike.cpp:324: sk_bzero(dfStorage.get(), dfSize);
On 2014/03/10 17:58:41, bsalomon wrote:
> We get here with color fonts (i.e. fUseDistanceField can be true)?

We currently have no way to tell from the SkPaint whether a typeface is color or
not until we request the FontScaler -- which we don't do until after we've
already chosen our rendering method (bitmap vs d.f.). I'm not sure at the moment
what the right solution is.

[jvanverth1, 2014-03-10 18:42:06]

https://codereview.chromium.org/178543007/diff/130001/gm/gmmain.cpp
File gm/gmmain.cpp (right):

https://codereview.chromium.org/178543007/diff/130001/gm/gmmain.cpp#newcode2416
gm/gmmain.cpp:2416: if ((kGPU_Backend == config.fBackend)) {
On 2014/03/10 15:48:11, robertphillips wrote:
> extra space somewhere?

Done.

https://codereview.chromium.org/178543007/diff/130001/src/core/SkDistanceFiel...
File src/core/SkDistanceFieldGen.cpp (right):

https://codereview.chromium.org/178543007/diff/130001/src/core/SkDistanceFiel...
src/core/SkDistanceFieldGen.cpp:1: /*
On 2014/03/10 15:48:11, robertphillips wrote:
> 2014?

Done.

https://codereview.chromium.org/178543007/diff/150001/src/core/SkDistanceFiel...
File src/core/SkDistanceFieldGen.cpp (right):

https://codereview.chromium.org/178543007/diff/150001/src/core/SkDistanceFiel...
src/core/SkDistanceFieldGen.cpp:77: float temp = dx;
On 2014/03/10 17:58:41, bsalomon wrote:
> feel free to ignore, but there is SkTSwap

Done.

https://codereview.chromium.org/178543007/diff/150001/src/core/SkDistanceFiel...
File src/core/SkDistanceFieldGen.h (right):

https://codereview.chromium.org/178543007/diff/150001/src/core/SkDistanceFiel...
src/core/SkDistanceFieldGen.h:10: // this assumes the client has already
allocated the necessary space in distanceField
On 2014/03/10 17:58:41, bsalomon wrote:
> It seems like this could use some more descriptive comments.

Done.

[jvanverth1, 2014-03-10 18:45:31]

The CQ bit was checked by jvanverth@google.com

[commit-bot: I haz the power, 2014-03-10 18:45:35]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/jvanverth@google.com/178543007/170001

[bungeman-skia, 2014-03-10 19:00:29]

https://codereview.chromium.org/178543007/diff/150001/src/gpu/GrTextStrike.cpp
File src/gpu/GrTextStrike.cpp (right):

https://codereview.chromium.org/178543007/diff/150001/src/gpu/GrTextStrike.cp...
src/gpu/GrTextStrike.cpp:324: sk_bzero(dfStorage.get(), dfSize);
On 2014/03/10 18:16:22, JimVV wrote:
> On 2014/03/10 17:58:41, bsalomon wrote:
> > We get here with color fonts (i.e. fUseDistanceField can be true)?
> 
> We currently have no way to tell from the SkPaint whether a typeface is color
or
> not until we request the FontScaler -- which we don't do until after we've
> already chosen our rendering method (bitmap vs d.f.). I'm not sure at the
moment
> what the right solution is.

This has been somewhat up in the air, but it looks like for color bitmap fonts
that everyone is settling on knowing up front if they're color or not (i.e.
there are no 'mixed' fonts). If we ever get around to color vector fonts (e.g.
the svg in otf specification) we'll need to pass around SkPictures or something.
In any event, it doesn't look like anyone is planning on supporting mixed fonts,
so maybe we can add a 'type' to the typeface which states if it's bitmap,
outline, or picture.

[commit-bot: I haz the power, 2014-03-10 19:39:06]

Change committed as 13729

[hal.canary, 2014-03-10 20:37:32]

A revert of this CL has been created in
https://codereview.chromium.org/190753015/ by halcanary@google.com.

The reason for reverting is: multiple compile errors.

[jvanverth1, 2014-03-11 15:24:41]

The CQ bit was checked by jvanverth@google.com

[commit-bot: I haz the power, 2014-03-11 15:24:55]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/jvanverth@google.com/178543007/190001

[commit-bot: I haz the power, 2014-03-11 15:57:50]

Change committed as 13740