Fractional advance widths were causing subtle problems with text
positioning when the same text was drawn with different spans in the
hwui renderer. Quantizing the coordinates on layout (as opposed to
waiting until the renderer draws the glyphs) solves the problem.

This patch also fixes a discrepancy between x position and advance
widths when letterspacing.

Bug: 17347779
Change-Id: Ia705944047408c2839d5ad078eefd6bbec446872

This reduces another allocation (last one?) we were doing when
fulfilling shaping requests from the cache.

Bug: 17111260
Change-Id: Ieb8ae1ccfcaacedb257e1e9263777f10623aaf98

C++ local var initialization always tricks me.  Previously, Layout
didn't have a constructor, which meant that defining it on the stack
left mAdvance uninitialized.  This was not an issue when we were doing
"new Layout()", since that invokes zero-initialization, but was an
issue for the skipCache path that was allocating layout on stack by
just "Layout l" instead of "Layout l = Layout()".  To avoid surprises,
add a constructors that clears everything.

Also adds reset() method to reset the layout for reuse.

Change-Id: I3e02f00da9dd7d360abe13f63c310f6882292d0a

Avoid copying the string for cache lookup.

Bug: 17111260
Change-Id: Ic220bfc991fc6b3dada197304aabdf72a8941bd7

Bug: 15246510
Change-Id: I544915d29b2be4fb9f82f1989188a3a918c50fbc

All usage is ported to the new doLayout() API now.

Bug: 16651112
Change-Id: I2c959138a69853b5e30098889d771fe5f4cfaa66

New API removes CSS string and directly takes needed objects.

Bug: 16651112
Change-Id: Ie5f7c2ab05be6cbd77cae0a5fd6bb453771ada59

Replaces invalid unicode with replacement character U+FFFD and always
makes forward progress.

Bug: 15849380

Change-Id: Ic59ef6c64b0f5c4450bcae61597adcc269d6e7c5

Extract language from FontStyle during shaping.  Don't attach CSS
to LayoutContext.

Change-Id: Ie621d3415410178d0d15fa7b810eb8e412342ab6

It has been unused outside minikin.

Change-Id: Iaa2237767d81c77f90d0264e633375e601dd72f1

Bug: 15594400
Change-Id: Ied94d7674be4097b0f44c9b0770d3294dc6433c1

Bug: 15849380
Change-Id: Ib5285e57c5806bd399600fadd56e8bc809da323f

Proper Japanese layout requires sophisticated rules for spacing
punctuation, not just turning on the "palt" (proportional alternate)
feature. Until we can support the whole set, roll back palt.

Change-Id: If2359c529b70b1dd45dddc00e5f4aa1c91f8b0e9

Expose a method to purge caches used for TextLayout, useful for low
memory conditions.

Change-Id: I92f41afe987b7be4af5ca0a0c50fb51be35a2758

This patch adds support for computing when fake bold and fake italics
are needed (because the styles are requested but not provided by the
matching FontFamily), and providing them as part of the layout result.

Part of the fix for bug 15436379 Fake bold doesn't fully work (Minikin)

Change-Id: I180c034b559837943673b5c272c8e890178dff0d

This patch adds support for computing when fake bold and fake italics
are needed (because the styles are requested but not provided by the
matching FontFamily), and providing them as part of the layout result.

Part of the fix for bug 15436379 Fake bold doesn't fully work (Minikin)

Change-Id: I180c034b559837943673b5c272c8e890178dff0d

We want to test configurations where the Noto Japanese font will have
its "palt" feature (to select tighter spacing in kana) will be enabled
for framework but not WebView or Chrome rendering of Japanese text. This
patch simply hardcodes this feature on.

This is also a first step towards more general setting of OpenType
features. The hardcoded feature list will grow into one set by
parameters which will eventually be plumbed up to Java.

Change-Id: Ie284e0487a1434155c8ac1cb68ddc4fc4b3c018a

This patch completes support for adding context for complex script
layout, for example when a string with joins straddles two spans.

Part of the fix for 15431028: "Properly support context for joining
scripts (Minikin)"

Change-Id: I65b0833be92eb477aa531bbef0ac6eddeb3a962a

Change internal plumbing of paint flags (including CssParse) to uint32_t
consistently, to match the type used in the client. This will probably
prevent compiler warnings. Also renames "float" to "double" to avoid
confusion about precision.

Change-Id: I80374712c4067ca9e7711cc2d4ec33c440ab9c7c

Missed a slightly mismatched type (int vs int32_t) from a previous code
review.

Change-Id: Ib56775a3a1a6ec3763da7f7432186954251cc048

Adds pseudo-css properties for scaleX and skewX, as well as paint flags,
and plumb them through to the MinikinPaint abstraction and to Harfbuzz,
to support nontrivial scale and stretch of text.

This is the Minikin part of the fix for bug 15186705 "Usability of the
suggestion strip in recent OTA's is severely reduced"

Change-Id: Ifa60355e086e4691ff92c5d50d84eb7cea0fea95

This patch adds a "lang" pseudo-CSS property and uses it both to select
an appropriate font and control the "locl" OpenType feature to get the
most appropriate rendering for the langauge and script.  In addition,
the "-minikin-variant" property selects between "compact" and "elegant"
variants of a font, as the former is needed for vertically cramped
spaces.

This is part of the fix for bug 15179652 "Japanese font isn't shown on
LMP".

Change-Id: I7fab23c12d4c797a6d339a16e497b79a3afe9df1

The context start offset wasn't being taken into account for
accumulating the advance values, leading in some cases to array index
overflow.

This is a fix for bug 15327918 "SIGSEGV in
android::MinikinFontSkia::GetSkTypeface()"

Change-Id: I9b646785724c9b72d862b822cd84661c106fbe52

This is a fix for bug 15252902 "Crash observed on keep launch or
existing youtube app after playing video". It was doing the test for a
null font after trying to resolve the font in a cache, which caused a
crash when there was no font for the run. This patch just tests before
cache lookup.

Change-Id: Iee41f7ce6b69cb09438462b6aaa916f242da7b77

This patch adds caching for both layouts and for HarfBuzz face objects.
The granularity of the cache for layouts is words, so it splits the
input string at word boundaries (using a heuristic). There are is also
some refactoring to reduce the amount of allocation and copying, and
movement towards properly supporting contexts.

The size of the caches is a fixed number of entries; thus, it is
possible to consume a large amount of memory by filling the cache with
lots of large strings. This should be refined towards a scheme that
bounds the total memory used by the cache.

This patch fixes bug 15237293 "Regression: Measure performance is
significantly slower with minikin".

Change-Id: Ie8176857e2d78656ce5479a7c04969819ef2718d

This is a fix for bug 15130102 "Language name for Hebrew displayed the
wrong way around on keyboard".

This patch extends the previous BiDi support (when the direction for the
entire string was given by the caller) to run the BiDi algorithm
(provided by ICU) over the string to break it into BiDi runs. Thus, it
handles mixed LTR and RTL strings in a single layout, and also respects
heuristics for inferring the paragraph direction from the string.

Change-Id: Ia4b869de3c139c5a7d16b8ce7766870b98a815ea
(cherry picked from commit 4b3a9411)

This patch adds caching for both layouts and for HarfBuzz face objects.
The granularity of the cache for layouts is words, so it splits the
input string at word boundaries (using a heuristic). There are is also
some refactoring to reduce the amount of allocation and copying, and
movement towards properly supporting contexts.

The size of the caches is a fixed number of entries; thus, it is
possible to consume a large amount of memory by filling the cache with
lots of large strings. This should be refined towards a scheme that
bounds the total memory used by the cache.

Change-Id: Ie8176857e2d78656ce5479a7c04969819ef2718d

These changes were supposed to be committed in the previous patch
"Better refcounting and locking" but seem to have gotten lost in a
rebase. It fixes a memory leak and some possible race conditions.

Change-Id: I54ca1e37500ec49756fe317cc6d6d03da9911501

This patch extends the previous BiDi support (when the direction for the
entire string was given by the caller) to run the BiDi algorithm
(provided by ICU) over the string to break it into BiDi runs. Thus, it
handles mixed LTR and RTL strings in a single layout, and also respects
heuristics for inferring the paragraph direction from the string.

Change-Id: Ia4b869de3c139c5a7d16b8ce7766870b98a815ea

These changes were supposed to be committed in the previous patch
"Better refcounting and locking" but seem to have gotten lost in a
rebase. It fixes a memory leak and some possible race conditions.

Change-Id: I54ca1e37500ec49756fe317cc6d6d03da9911501

This patch contains a very basic implementation of BiDi. It respects the
BiDi flags passed in as an explicit parameter (through the
"-minikin-bidi" pseudo-CSS property), but doesn't yet do its own BiDi
run detection. It also takes some shortcuts (marked as TODO) that are
based on reasonable assumptions of the current font stack, but not
universally valid.

Even with these shortcomings, it seems to display RTL text from TextView
correctly.

Change-Id: I223433923c4eb06f90c0327e86bfbe0aff71d4f5

This patch fixes a problem where int and ssize_t were being conflated.

Change-Id: I642a4ee1d59d81723034fdfe33bd8ca29a5dc322

All major externally accessible objects (especially FontFamily and
FontCollection) are now reference counted. In addition, there is a
global lock intended to make operations thread-safe.

WIP notice: in this version of the patch, not all external API entry
points are protected by the lock. That should be fixed.

Change-Id: I14106196e99eb101e8bf1bcb4b81359759d2086c

This patch improves script run itemization and also exposes metrics
and bounds for layouts. In addition, there is a fair amount of internal
cleanup, including ref counting, and making the MinikinFont abstraction
strong enough to support both FreeType and Skia implementations. There
is also a sample implementation using Skia, in the sample directory.

As part of its functionality, his patch measures the bounds of the
layout and gives access through Layout::GetBounds().  The corresponding
method is not implemented in the FreeType-only implementation of
MinikinFont, so that will probably have to be fixed.

Change-Id: Ib1a3fe9d7c90519ac651fb4aa957848e4bb758ec

This commit removes the direct dependency on FreeType and replaces it
with a MinikinFont abstraction, which is designed to support both
FreeType and Skia fonts (and possibly others in the future).

Also adds a "total advance" to the Layout, with an API for retrieving
it.

Change-Id: If20f92db9a43fd15b0fe9794b761ba00fb21338c

This is the initial draft of Minikin, a library intended to perform text
layout functions. This version does basic weight selection and font runs
for scripts, and also has a simple renderer for drawing into bitmaps,
but is lacking measurement, line breaking, and a number of other
important features. It also lacks caching and other performance
refinements.

Change-Id: I789a2e47d11d71202dc84b4751b51a5e2cd9c451