Textblob-based vertical text painting

Textblob-based vertical text painting

We're currently devolving to the legacy API when painting vertical text
(due to mixed rotations required for upright vs. non-upright subruns).

This CL enhances the textblob paint path to also handle mixed/upright
subruns, unifies the glyph buffer paint methods and removes the legacy
path (Font::drawGlyphs, SkCanvas::drawPosText).

Main changes:

  * refactor the one-shot Font::buildTextBlob() as a text blob producer
  * refactor Font::drawGlypBuffer() as a text blob consumer
  * fold the drawGlyphs x-offset adjustments for vertical into the blob
    factory
  * fold the drawGlyphs CCW rotation for vertical text into
    drawGlyphBuffer

The blob factory is mostly lifted from Font::buildTextBlob(), with
additional logic to emit multiple blobs (when rotation changes) and
handle x-offset adjustments.

Note 1: this doesn't change the blob caching policy: only glyph buffers
which can be represented as a single, non-rotated blob are cached
(same as before).

Note 2: we now avoid the extra offset array stack copy in drawGlyphs by
applying the adjustment on the fly, as we copy data into the blob.

BUG=465353
R=jbroman@chromium.org,eae@chromium.org,drott@chromium.org

Committed: https://crrev.com/d8511df9e68db1fd3dfeda7ad271a4dd4caf0250
Cr-Commit-Position: refs/heads/master@{#367163}

[f(malita), 2015-12-30 13:57:10]

Description was changed from

==========
Textblob-based vertical text painting

We're currently devolving to the legacy API when painting vertical text
(due to mixed rotations required for upright vs. non-upright subruns).

This CL enhances the textblob paint path to also handle mixed/upright
subruns, unifies the glyph buffer paint methods and removes the legacy
path (Font::drawGlyphs).

The main change is the introduction of GlyphBufferPainter, which

  1) converts a GlyphBuffer into one or more SkTextBlobs
  2) draws the resulting blobs
  3) optionally returns a blob suitable for caching (when feasible)

The blob factory is mostly lifted from Font::buildTextBlob(), with
additional logic to handle multiple blobs and x-offset adjustments
for upright vertical text.

Note that this doesn't change the blob caching policy: only glyph
buffers which can be represented as a single, non-rotated blob are
cached (same as before).
==========

to

==========
Textblob-based vertical text painting

We're currently devolving to the legacy API when painting vertical text
(due to mixed rotations required for upright vs. non-upright subruns).

This CL enhances the textblob paint path to also handle mixed/upright
subruns, unifies the glyph buffer paint methods and removes the legacy
path (Font::drawGlyphs, SkCanvas::drawPosText).

Main changes:

  * refactor the one-shot Font::buildTextBlob() as a text blob producer
  * refactor Font::drawGlypBuffer() as a text blob consumer
  * fold the drawGlyphs x-offset adjustments for vertical text logic
    into the blob factory
  * fold the drawGlyphs CCW rotation for vertical text into
    drawGlyphBuffer

The blob factory is mostly lifted from Font::buildTextBlob(), with
additional logic to emit multiple blobs (when rotation changes) and
handle x-offset adjustments.

Note that this doesn't change the blob caching policy: only glyph
buffers which can be represented as a single, non-rotated blob are
cached (same as before).

BUG=465353
R=jbroman@chromium.org,eae@chromium.org,drott@chromium.org
==========

[f(malita), 2015-12-30 13:58:23]

Description was changed from

==========
Textblob-based vertical text painting

We're currently devolving to the legacy API when painting vertical text
(due to mixed rotations required for upright vs. non-upright subruns).

This CL enhances the textblob paint path to also handle mixed/upright
subruns, unifies the glyph buffer paint methods and removes the legacy
path (Font::drawGlyphs, SkCanvas::drawPosText).

Main changes:

  * refactor the one-shot Font::buildTextBlob() as a text blob producer
  * refactor Font::drawGlypBuffer() as a text blob consumer
  * fold the drawGlyphs x-offset adjustments for vertical text logic
    into the blob factory
  * fold the drawGlyphs CCW rotation for vertical text into
    drawGlyphBuffer

The blob factory is mostly lifted from Font::buildTextBlob(), with
additional logic to emit multiple blobs (when rotation changes) and
handle x-offset adjustments.

Note that this doesn't change the blob caching policy: only glyph
buffers which can be represented as a single, non-rotated blob are
cached (same as before).

BUG=465353
R=jbroman@chromium.org,eae@chromium.org,drott@chromium.org
==========

to

==========
Textblob-based vertical text painting

We're currently devolving to the legacy API when painting vertical text
(due to mixed rotations required for upright vs. non-upright subruns).

This CL enhances the textblob paint path to also handle mixed/upright
subruns, unifies the glyph buffer paint methods and removes the legacy
path (Font::drawGlyphs, SkCanvas::drawPosText).

Main changes:

  * refactor the one-shot Font::buildTextBlob() as a text blob producer
  * refactor Font::drawGlypBuffer() as a text blob consumer
  * fold the drawGlyphs x-offset adjustments for vertical into the blob
    factory
  * fold the drawGlyphs CCW rotation for vertical text into
    drawGlyphBuffer

The blob factory is mostly lifted from Font::buildTextBlob(), with
additional logic to emit multiple blobs (when rotation changes) and
handle x-offset adjustments.

Note that this doesn't change the blob caching policy: only glyph
buffers which can be represented as a single, non-rotated blob are
cached (same as before).

BUG=465353
R=jbroman@chromium.org,eae@chromium.org,drott@chromium.org
==========

[f(malita), 2015-12-30 14:19:57]

Description was changed from

==========
Textblob-based vertical text painting

We're currently devolving to the legacy API when painting vertical text
(due to mixed rotations required for upright vs. non-upright subruns).

This CL enhances the textblob paint path to also handle mixed/upright
subruns, unifies the glyph buffer paint methods and removes the legacy
path (Font::drawGlyphs, SkCanvas::drawPosText).

Main changes:

  * refactor the one-shot Font::buildTextBlob() as a text blob producer
  * refactor Font::drawGlypBuffer() as a text blob consumer
  * fold the drawGlyphs x-offset adjustments for vertical into the blob
    factory
  * fold the drawGlyphs CCW rotation for vertical text into
    drawGlyphBuffer

The blob factory is mostly lifted from Font::buildTextBlob(), with
additional logic to emit multiple blobs (when rotation changes) and
handle x-offset adjustments.

Note that this doesn't change the blob caching policy: only glyph
buffers which can be represented as a single, non-rotated blob are
cached (same as before).

BUG=465353
R=jbroman@chromium.org,eae@chromium.org,drott@chromium.org
==========

to

==========
Textblob-based vertical text painting

We're currently devolving to the legacy API when painting vertical text
(due to mixed rotations required for upright vs. non-upright subruns).

This CL enhances the textblob paint path to also handle mixed/upright
subruns, unifies the glyph buffer paint methods and removes the legacy
path (Font::drawGlyphs, SkCanvas::drawPosText).

Main changes:

  * refactor the one-shot Font::buildTextBlob() as a text blob producer
  * refactor Font::drawGlypBuffer() as a text blob consumer
  * fold the drawGlyphs x-offset adjustments for vertical into the blob
    factory
  * fold the drawGlyphs CCW rotation for vertical text into
    drawGlyphBuffer

The blob factory is mostly lifted from Font::buildTextBlob(), with
additional logic to emit multiple blobs (when rotation changes) and
handle x-offset adjustments.

Note 1: this doesn't change the blob caching policy: only glyph buffers
which can be represented as a single, non-rotated blob are cached
(same as before).

Note 2: we now avoid the extra offset array stack copy in drawGlyphs by
applying the adjustment on the fly, as we copy data into the blob.

BUG=465353
R=jbroman@chromium.org,eae@chromium.org,drott@chromium.org
==========

[f(malita), 2015-12-30 14:23:48]

fmalita@chromium.org changed reviewers:
+ drott@chromium.org, eae@chromium.org, jbroman@chromium.org

[f(malita), 2015-12-30 14:25:16]

No functional changes, no (notable) perf changes:
https://storage.cloud.google.com/cluster-telemetry/tasks/chromium_perf_runs/f...

[eae, 2015-12-30 15:55:53]

Very nice, LGTM!

[jbroman, 2015-12-30 16:07:13]

Looks reasonable; have you run Cluster Telemetry to confirm there is no
regression for the normal (single non-rotated run) case?

https://codereview.chromium.org/1550993002/diff/120001/third_party/WebKit/Sou...
File third_party/WebKit/Source/platform/fonts/Font.cpp (right):

https://codereview.chromium.org/1550993002/diff/120001/third_party/WebKit/Sou...
third_party/WebKit/Source/platform/fonts/Font.cpp:259: std::pair<RefPtr<const
SkTextBlob>, bool> next()
nit: even though it's local, an enum would be clearer to me than a boolean.

[f(malita), 2015-12-30 16:22:43]

On 2015/12/30 16:07:13, jbroman wrote:
> Looks reasonable; have you run Cluster Telemetry to confirm there is no
> regression for the normal (single non-rotated run) case?

Yes:
https://storage.cloud.google.com/cluster-telemetry/tasks/chromium_perf_runs/f...

https://codereview.chromium.org/1550993002/diff/120001/third_party/WebKit/Sou...
File third_party/WebKit/Source/platform/fonts/Font.cpp (right):

https://codereview.chromium.org/1550993002/diff/120001/third_party/WebKit/Sou...
third_party/WebKit/Source/platform/fonts/Font.cpp:259: std::pair<RefPtr<const
SkTextBlob>, bool> next()
On 2015/12/30 16:07:13, jbroman wrote:
> nit: even though it's local, an enum would be clearer to me than a boolean.

Makes sense, done.

[jbroman, 2015-12-30 16:24:35]

lgtm

[f(malita), 2015-12-30 16:38:26]

The CQ bit was checked by fmalita@chromium.org

[f(malita), 2015-12-30 16:38:27]

The patchset sent to the CQ was uploaded after l-g-t-m from eae@chromium.org,
jbroman@chromium.org
Link to the patchset: https://codereview.chromium.org/1550993002/#ps160001
(title: "missed one bool after enum update")

[commit-bot: I haz the power, 2015-12-30 16:38:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1550993002/160001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1550993002/160001

[commit-bot: I haz the power, 2015-12-30 17:56:02]

Description was changed from

==========
Textblob-based vertical text painting

We're currently devolving to the legacy API when painting vertical text
(due to mixed rotations required for upright vs. non-upright subruns).

This CL enhances the textblob paint path to also handle mixed/upright
subruns, unifies the glyph buffer paint methods and removes the legacy
path (Font::drawGlyphs, SkCanvas::drawPosText).

Main changes:

  * refactor the one-shot Font::buildTextBlob() as a text blob producer
  * refactor Font::drawGlypBuffer() as a text blob consumer
  * fold the drawGlyphs x-offset adjustments for vertical into the blob
    factory
  * fold the drawGlyphs CCW rotation for vertical text into
    drawGlyphBuffer

The blob factory is mostly lifted from Font::buildTextBlob(), with
additional logic to emit multiple blobs (when rotation changes) and
handle x-offset adjustments.

Note 1: this doesn't change the blob caching policy: only glyph buffers
which can be represented as a single, non-rotated blob are cached
(same as before).

Note 2: we now avoid the extra offset array stack copy in drawGlyphs by
applying the adjustment on the fly, as we copy data into the blob.

BUG=465353
R=jbroman@chromium.org,eae@chromium.org,drott@chromium.org
==========

to

==========
Textblob-based vertical text painting

We're currently devolving to the legacy API when painting vertical text
(due to mixed rotations required for upright vs. non-upright subruns).

This CL enhances the textblob paint path to also handle mixed/upright
subruns, unifies the glyph buffer paint methods and removes the legacy
path (Font::drawGlyphs, SkCanvas::drawPosText).

Main changes:

  * refactor the one-shot Font::buildTextBlob() as a text blob producer
  * refactor Font::drawGlypBuffer() as a text blob consumer
  * fold the drawGlyphs x-offset adjustments for vertical into the blob
    factory
  * fold the drawGlyphs CCW rotation for vertical text into
    drawGlyphBuffer

The blob factory is mostly lifted from Font::buildTextBlob(), with
additional logic to emit multiple blobs (when rotation changes) and
handle x-offset adjustments.

Note 1: this doesn't change the blob caching policy: only glyph buffers
which can be represented as a single, non-rotated blob are cached
(same as before).

Note 2: we now avoid the extra offset array stack copy in drawGlyphs by
applying the adjustment on the fly, as we copy data into the blob.

BUG=465353
R=jbroman@chromium.org,eae@chromium.org,drott@chromium.org
==========

[commit-bot: I haz the power, 2015-12-30 17:56:03]

Committed patchset #9 (id:160001)

[commit-bot: I haz the power, 2015-12-30 17:56:56]

Description was changed from

==========
Textblob-based vertical text painting

We're currently devolving to the legacy API when painting vertical text
(due to mixed rotations required for upright vs. non-upright subruns).

This CL enhances the textblob paint path to also handle mixed/upright
subruns, unifies the glyph buffer paint methods and removes the legacy
path (Font::drawGlyphs, SkCanvas::drawPosText).

Main changes:

  * refactor the one-shot Font::buildTextBlob() as a text blob producer
  * refactor Font::drawGlypBuffer() as a text blob consumer
  * fold the drawGlyphs x-offset adjustments for vertical into the blob
    factory
  * fold the drawGlyphs CCW rotation for vertical text into
    drawGlyphBuffer

The blob factory is mostly lifted from Font::buildTextBlob(), with
additional logic to emit multiple blobs (when rotation changes) and
handle x-offset adjustments.

Note 1: this doesn't change the blob caching policy: only glyph buffers
which can be represented as a single, non-rotated blob are cached
(same as before).

Note 2: we now avoid the extra offset array stack copy in drawGlyphs by
applying the adjustment on the fly, as we copy data into the blob.

BUG=465353
R=jbroman@chromium.org,eae@chromium.org,drott@chromium.org
==========

to

==========
Textblob-based vertical text painting

We're currently devolving to the legacy API when painting vertical text
(due to mixed rotations required for upright vs. non-upright subruns).

This CL enhances the textblob paint path to also handle mixed/upright
subruns, unifies the glyph buffer paint methods and removes the legacy
path (Font::drawGlyphs, SkCanvas::drawPosText).

Main changes:

  * refactor the one-shot Font::buildTextBlob() as a text blob producer
  * refactor Font::drawGlypBuffer() as a text blob consumer
  * fold the drawGlyphs x-offset adjustments for vertical into the blob
    factory
  * fold the drawGlyphs CCW rotation for vertical text into
    drawGlyphBuffer

The blob factory is mostly lifted from Font::buildTextBlob(), with
additional logic to emit multiple blobs (when rotation changes) and
handle x-offset adjustments.

Note 1: this doesn't change the blob caching policy: only glyph buffers
which can be represented as a single, non-rotated blob are cached
(same as before).

Note 2: we now avoid the extra offset array stack copy in drawGlyphs by
applying the adjustment on the fly, as we copy data into the blob.

BUG=465353
R=jbroman@chromium.org,eae@chromium.org,drott@chromium.org

Committed: https://crrev.com/d8511df9e68db1fd3dfeda7ad271a4dd4caf0250
Cr-Commit-Position: refs/heads/master@{#367163}
==========

[commit-bot: I haz the power, 2015-12-30 17:56:59]

Patchset 9 (id:??) landed as
https://crrev.com/d8511df9e68db1fd3dfeda7ad271a4dd4caf0250
Cr-Commit-Position: refs/heads/master@{#367163}