Creating a helper class for reversing timing functions.

Creating a helper class for reversing timing functions.

DEPENDS=https://codereview.chromium.org/60323005/ - Adding operator== to TimingFunctionTestHelper.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=161686

[mithro-old, 2013-11-04 13:06:36]

Hi Steve,

This is the code which reverses timing functions using a helper class rather
than a reverse() method as requested. (After the discussion all support for
reversing step functions has been dropped.)

I originally wanted it to be a private inner class of the CompositorAnimations
class, but you can't friend that easily and it would have created circular
references.

It depends on;
 * https://codereview.chromium.org/57563002/ - Adding operator== for
ChainedTimingFunction 
 * https://codereview.chromium.org/52923003/ - Fixing reflectivity of operator==
for timing functions. 
 * https://codereview.chromium.org/39223002/ - TimingFunction test helper.

Tim

[mithro-old, 2013-11-06 04:05:24]

Hi Steve,

I have rebased this code on top of https://codereview.chromium.org/60323005/ -
Adding operator== to TimingFunctionTestHelper.

I separated this code from the rest of the code in CompositorAnimations because
it becomes;
 * easier to understand the code
 * easier to test and verify the code works
 * easier to remove once the Compositor understands reverse time.

Will upload the code which uses this once I verify all the tests compile + pass.

Tim

[Steve Block, 2013-11-06 06:06:23]

lgtm

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
File Source/core/animation/CompositorAnimations.cpp (right):

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
Source/core/animation/CompositorAnimations.cpp:65: // maintain the invariant
that it runs from (0, 0) to (1, 1).
You can probably remove this, given the comment in the header

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
File Source/core/animation/CompositorAnimations.h (right):

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
Source/core/animation/CompositorAnimations.h:43: // t=0.5 stays the same.
This is a little vague. Given an input timing function and associated start and
end keyframes, we need a timing function such that the behavior with the
keyframes swapped is equivalent to reversing time with the input timing function
and keyframes. This means flipping the timing function about x=0.5 and about
y=0.5.

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
Source/core/animation/CompositorAnimations.h:49: static
PassRefPtr<TimingFunction> reverse(const ChainedTimingFunction* timefunc);
Do the type-specific reverse methods need to be in this header file?

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
File Source/core/animation/CompositorAnimationsTest.cpp (right):

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
Source/core/animation/CompositorAnimationsTest.cpp:88: RefPtr<TimingFunction>
cubicCustomTimingReversed = CubicBezierTimingFunction::create(0, 1.0-(-1.73),
1.0-0.17, 1.0-0.67);
Spaces around operators

[mithro-old, 2013-11-07 00:56:58]

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
File Source/core/animation/CompositorAnimations.cpp (right):

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
Source/core/animation/CompositorAnimations.cpp:65: // maintain the invariant
that it runs from (0, 0) to (1, 1).
On 2013/11/06 06:06:23, Steve Block wrote:
> You can probably remove this, given the comment in the header

Done.

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
File Source/core/animation/CompositorAnimationsTest.cpp (right):

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
Source/core/animation/CompositorAnimationsTest.cpp:88: RefPtr<TimingFunction>
cubicCustomTimingReversed = CubicBezierTimingFunction::create(0, 1.0-(-1.73),
1.0-0.17, 1.0-0.67);
On 2013/11/06 06:06:23, Steve Block wrote:
> Spaces around operators

Done.

[mithro-old, 2013-11-07 01:02:36]

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
File Source/core/animation/CompositorAnimations.h (right):

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
Source/core/animation/CompositorAnimations.h:43: // t=0.5 stays the same.
On 2013/11/06 06:06:23, Steve Block wrote:
> This is a little vague. Given an input timing function and associated start
and
> end keyframes, we need a timing function such that the behavior with the
> keyframes swapped is equivalent to reversing time with the input timing
function
> and keyframes. This means flipping the timing function about x=0.5 and about
> y=0.5.

Done.

https://codereview.chromium.org/51943004/diff/220001/Source/core/animation/Co...
Source/core/animation/CompositorAnimations.h:49: static
PassRefPtr<TimingFunction> reverse(const ChainedTimingFunction* timefunc);
On 2013/11/06 06:06:23, Steve Block wrote:
> Do the type-specific reverse methods need to be in this header file?

Done.

[commit-bot: I haz the power, 2013-11-09 05:42:49]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mithro@mithis.com/51943004/340001

[commit-bot: I haz the power, 2013-11-09 06:10:17]

Sorry for I got bad news for ya.
Compile failed with a clobber build on linux_blink_rel.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_blin...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2013-11-09 09:31:28]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mithro@mithis.com/51943004/500001

[commit-bot: I haz the power, 2013-11-09 11:00:08]

Change committed as 161686