cc: Rewrite PageScaleAnimation for new coordinate system.

cc: Rewrite PageScaleAnimation for new coordinate system.

- I moved PageScaleAnimation to work entirely at root content layer
  scale, to be consistent with the new pinch zoom code. This avoids the
  need for any scaling of scroll offsets. However, everything must now
  be in floating point, and the complexity is moved into viewport size
  calculation instead.

- I also took the opportunity to add support for two anchors instead of
  just one, introducing an additional level of interpolation. This
  makes the animation appear less jarring when we clamp it to document
  edge, and it also removes the need for special-casing translation-only
  animations.

BUG=152505
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=166855

[aelias_OOO_until_Jul13, 2012-10-10 23:34:33]

Here's the first of many changes to make Android's features consistent with the
new pinch zoom approach.  I also threw in some cleanup and added a feature that
was on the backburner.

[aelias_OOO_until_Jul13, 2012-10-12 01:05:34]

Adding klobag@ to review the anchor stuff.

[klobag.chromium, 2012-10-26 19:53:41]

On 2012/10/12 01:05:34, aelias wrote:
> Adding klobag@ to review the anchor stuff.

Sorry for the late reply. Can you rebase first as all the file name has changed?

[aelias_OOO_until_Jul13, 2012-10-30 22:34:20]

Rebased, PTAL.

[jamesr, 2012-10-30 22:45:18]

lgtm, but Grace should review the anchor stuff

[aelias_OOO_until_Jul13, 2012-11-08 21:18:51]

Rebased and cleaned up.  trchen@ can review the math as he's started to work on
page scale.

[trchen, 2012-11-09 00:56:34]

On 2012/11/08 21:18:51, aelias wrote:
> Rebased and cleaned up.  trchen@ can review the math as he's started to work
on
> page scale.

LGTM. makes sense to me.

[commit-bot: I haz the power, 2012-11-09 02:30:39]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/aelias@chromium.org/11090062/15006

[commit-bot: I haz the power, 2012-11-09 04:46:58]

Change committed as 166855

[danakj, 2012-11-09 05:06:49]

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.cc
File cc/page_scale_animation.cc (left):

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:9: #include "cc/geometry.h"
keep this. see below.

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.cc
File cc/page_scale_animation.cc (right):

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:16: gfx::PointF toPointF(const gfx::Vector2dF&
vector)
use gfx::PointAtOffsetFromOrigin instead.

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:25: gfx::Vector2dF normalized(denormalized);
You could use ScaleVector2d() from cc/geometry.h to do this in one statement.

I would move it to gfx:: and change this callsite in
https://codereview.chromium.org/11293193/

Otherwise:

return denormalized.Scale(1 / viewportSize.width(), 1 / viewportSize.height());

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:32: gfx::Vector2dF denormalized(normalized);
same

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:42: return result;
return start + (end - start).Scale(interp);

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:107: gfx::SizeF scaledViewportSize = m_viewportSize;
return m_viewportSize.Scale(1 / pageScaleFactor);

that way i'll see it and switch it to gfx::ScaleSize()
https://codereview.chromium.org/11377068/

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:121: gfx::RectF
startRect(toPointF(m_startScrollOffset),
viewportSizeAtScale(m_startPageScaleFactor));
Don't make rects, just store the sizes. See below.

If you did want to make rects, use gfx::PointAtOffsetFromOrigin(vector).
After https://codereview.chromium.org/11293194/ you could do startRect =
Rect(size) + offset

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:135: gfx::Vector2dF normalized;
float widthScale = targetSize.width() - startSize.width();
float heightScale = targetHeight.width() - startHeight.width();

normalized = ScaleVector2d(m_startScrollOffset - m_targetScrollOffset, 1 /
widthScale, 1 / heightScale);


You shouldn't need to use vector.set_x() or set_y(). I think generally if you
do, you're doing something too awkwardly.

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:143: gfx::Vector2dF maxScrollPosition;
maxScrollOffset

Position is for Points.

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:146: m_targetScrollOffset.set_x(std::max<float>(0,
m_targetScrollOffset.x()));
Use cc/geometry.h methods, which will move to ui/gfx soon.

m_targetScrollOffset = ClampFromBelow(m_targetScrollOffset, gfx::Vector2d())

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:148:
m_targetScrollOffset.set_x(std::min<float>(maxScrollPosition.x(),
m_targetScrollOffset.x()));
m_targetScrollOffset = ClampFromAbove(m_targetScrollOffset, maxScrollOffset)

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:189: delta.Scale(interp);
you could use ScaleVector2d() from cc/geometry.h to do this in one statement.

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.h
File cc/page_scale_animation.h (right):

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.h...
cc/page_scale_animation.h:32: void zoomTo(const gfx::Vector2dF&
targetScrollOffset, float targetPageScaleFactor, double duration);
Pass by value for <= 4 ints or <= 2 floats.

https://codereview.chromium.org/11090062/diff/15006/cc/layer_tree_host_impl.cc
File cc/layer_tree_host_impl.cc (right):

https://codereview.chromium.org/11090062/diff/15006/cc/layer_tree_host_impl.c...
cc/layer_tree_host_impl.cc:295: void
LayerTreeHostImpl::startPageScaleAnimation(gfx::Vector2d targetPosition, bool
anchorPoint, float pageScale, base::TimeTicks startTime, base::TimeDelta
duration)
call it targetOffset, or change the type to a Point.

Vector2d = offset
Point = position

https://codereview.chromium.org/11090062/diff/15006/cc/layer_tree_host_impl.c...
cc/layer_tree_host_impl.cc:307: viewportSize = viewportSize.Scale(1 /
m_deviceScaleFactor);
Just use m_layoutViewportSize ?

https://codereview.chromium.org/11090062/diff/15006/cc/layer_tree_host_impl.c...
cc/layer_tree_host_impl.cc:318: gfx::Vector2dF scaledTargetPosition =
targetPosition;
scaledTargetOffset

https://codereview.chromium.org/11090062/diff/15006/cc/layer_tree_host_impl.h
File cc/layer_tree_host_impl.h (right):

https://codereview.chromium.org/11090062/diff/15006/cc/layer_tree_host_impl.h...
cc/layer_tree_host_impl.h:119: virtual void
startPageScaleAnimation(gfx::Vector2d targetPosition, bool anchorPoint, float
pageScale, base::TimeTicks startTime, base::TimeDelta duration) OVERRIDE;
call it targetOffset, or change the type to a Point.

Vector2d = offset
Point = position

[danakj, 2012-11-09 05:08:27]

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.cc
File cc/page_scale_animation.cc (right):

https://codereview.chromium.org/11090062/diff/13001/cc/page_scale_animation.c...
cc/page_scale_animation.cc:135: gfx::Vector2dF normalized;
On 2012/11/09 05:06:49, danakj wrote:
> float widthScale = targetSize.width() - startSize.width();
> float heightScale = targetHeight.width() - startHeight.width();

I mean: 

float widthScale = targetSize.width() - startSize.width();
float heightScale = targetSize.height() - startSize.height();