Optimize the characterNumberAtPositionCallback text query

Optimize the characterNumberAtPositionCallback text query

Refactor the calculateGlyphPositionWithoutTransform and
calculateGlyphBoundaries helpers to get logicalGlyphPositionToPhysical
and physicalGlyphExtents.
Use the new methods to implement characterNumberAtPositionCallback as an
iteration over the contributing glyphs, thereby avoiding the O(n^2) for
glyph bounds calculation.

Also fold calculateFragmentBoundaries into
characterNumberAtPositionCallback, because it is trivial, and most of it
is needed for the remaining part of the function too.

Committed: https://crrev.com/4be79e4d348ae00cd5ad7f78b3e3d9f5bf5d6842
Cr-Commit-Position: refs/heads/master@{#382557}

[fs, 2016-03-21 14:10:03]

fs@opera.com changed reviewers:
+ pdr@chromium.org

[pdr., 2016-03-21 22:55:57]

LGTM

https://codereview.chromium.org/1816073002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/layout/svg/SVGTextQuery.cpp (right):

https://codereview.chromium.org/1816073002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/layout/svg/SVGTextQuery.cpp:452: // Use the
SVGTextMetrics computed by SVGTextMetricsBuilder (which spends
Not your fault but can you clean this comment up? What does "to some degree"
mean?

[fs, 2016-03-22 10:55:30]

https://codereview.chromium.org/1816073002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/layout/svg/SVGTextQuery.cpp (right):

https://codereview.chromium.org/1816073002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/layout/svg/SVGTextQuery.cpp:452: // Use the
SVGTextMetrics computed by SVGTextMetricsBuilder (which spends
On 2016/03/21 at 22:55:56, pdr wrote:
> Not your fault but can you clean this comment up? What does "to some degree"
mean?

Well I think I wrote this comment, so somewhat my fault =). I think the "to some
degree" was getting at the poor quality of the advances/bounds in those cases at
the time of writing - hopefully it's better now.

Parenthesis removed.

[fs, 2016-03-22 11:46:38]

The CQ bit was checked by fs@opera.com

[fs, 2016-03-22 11:46:38]

The patchset sent to the CQ was uploaded after l-g-t-m from pdr@chromium.org
Link to the patchset: https://codereview.chromium.org/1816073002/#ps20001
(title: "Tidy up comment.")

[commit-bot: I haz the power, 2016-03-22 11:46:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1816073002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1816073002/20001

[commit-bot: I haz the power, 2016-03-22 12:25:28]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-03-22 12:26:23]

Description was changed from

==========
Optimize the characterNumberAtPositionCallback text query

Refactor the calculateGlyphPositionWithoutTransform and
calculateGlyphBoundaries helpers to get logicalGlyphPositionToPhysical
and physicalGlyphExtents.
Use the new methods to implement characterNumberAtPositionCallback as an
iteration over the contributing glyphs, thereby avoiding the O(n^2) for
glyph bounds calculation.

Also fold calculateFragmentBoundaries into
characterNumberAtPositionCallback, because it is trivial, and most of it
is needed for the remaining part of the function too.
==========

to

==========
Optimize the characterNumberAtPositionCallback text query

Refactor the calculateGlyphPositionWithoutTransform and
calculateGlyphBoundaries helpers to get logicalGlyphPositionToPhysical
and physicalGlyphExtents.
Use the new methods to implement characterNumberAtPositionCallback as an
iteration over the contributing glyphs, thereby avoiding the O(n^2) for
glyph bounds calculation.

Also fold calculateFragmentBoundaries into
characterNumberAtPositionCallback, because it is trivial, and most of it
is needed for the remaining part of the function too.

Committed: https://crrev.com/4be79e4d348ae00cd5ad7f78b3e3d9f5bf5d6842
Cr-Commit-Position: refs/heads/master@{#382557}
==========

[commit-bot: I haz the power, 2016-03-22 12:26:24]

Patchset 2 (id:??) landed as
https://crrev.com/4be79e4d348ae00cd5ad7f78b3e3d9f5bf5d6842
Cr-Commit-Position: refs/heads/master@{#382557}