Changes in this patch include
[x] Long(64-bit) is used to store native pointers in
AssetAtlasService and related classes as they can be 64-bit.
[x] Some minor changes have been done to conform with
standard JNI practice (e.g. use of jint instead of int
in JNI function prototypes)
Signed-off-by: Ashok Bhat <ashok.bhat@arm.com>
(cherry-picked from 4de3f481bc59ab4b766dc027e41aff7cda9d62f7)
Change-Id: If22daf40eef46f8df9f94d65ddcc52c45b3acf2a
Bug #10185769
The assets atlas contains assets that need to be blended and assets
that do not need to be blended. With a single merge id, currently
set to be the pointer to the atlas itself, draw ops merging could
generate batches of commands containing both opaque and translucent
assets. The blend state was chosen from only one of the assets in
the batch, leading either to inefficiencies (blending large opaque
assets) or incorrect behaviors (not blending translucent assets.)
This change introduces two new merge ids in the atlas: an opaque
key and a blend key. These keys are simple booleans set to false
and true respectively (the values do not matter really.) Their
memory addresses are used as the merge ids when createing draw ops
batches, allowing all opaque ops to be batched together and all
translucent ops to be batched together.
Change-Id: I114dba0533c44987e53864b471ccb28c811f2025
Bug #9589379
If the atlas is terminated/reinitialized and a view does not invalidate
in between it might end up using a stale AssetAtlas::Entry. This change
is similar to how 9patch meshes are cached in DrawPatchOp: we simply
track the generation ID of the cache to make sure we always use the
latest data.
Change-Id: Ib5abb3769d2ce0eabe9adc04e320ca27c422019e
The virtual textures would each have their own values for wrapping
and filtering which could lead to conflict and/or extraneous GL
commands being issued.
Change-Id: I64cb59a03e598f46bf645bd1d30fccfa63a07431
Bug #8833153
If Atlas::terminate() is called twice without an init() in between
libhwui would double-free Atlas::mImage. This lead to a lot of crashes
with the monkeys as they can easily trigger memory trims.
Change-Id: I96798414e5e71cd498aaca85a790661ebccdaa91
When the Android runtime starts, the system preloads a series of assets
in the Zygote process. These assets are shared across all processes.
Unfortunately, each one of these assets is later uploaded in its own
OpenGL texture, once per process. This wastes memory and generates
unnecessary OpenGL state changes.
This CL introduces an asset server that provides an atlas to all processes.
Note: bitmaps used by skia shaders are *not* sampled from the atlas.
It's an uncommon use case and would require extra texture transforms
in the GL shaders.
WHAT IS THE ASSETS ATLAS
The "assets atlas" is a single, shareable graphic buffer that contains
all the system's preloaded bitmap drawables (this includes 9-patches.)
The atlas is made of two distinct objects: the graphic buffer that
contains the actual pixels and the map which indicates where each
preloaded bitmap can be found in the atlas (essentially a pair of
x and y coordinates.)
HOW IS THE ASSETS ATLAS GENERATED
Because we need to support a wide variety of devices and because it
is easy to change the list of preloaded drawables, the atlas is
generated at runtime, during the startup phase of the system process.
There are several steps that lead to the atlas generation:
1. If the device is booting for the first time, or if the device was
updated, we need to find the best atlas configuration. To do so,
the atlas service tries a number of width, height and algorithm
variations that allows us to pack as many assets as possible while
using as little memory as possible. Once a best configuration is found,
it gets written to disk in /data/system/framework_atlas
2. Given a best configuration (algorithm variant, dimensions and
number of bitmaps that can be packed in the atlas), the atlas service
packs all the preloaded bitmaps into a single graphic buffer object.
3. The packing is done using Skia in a temporary native bitmap. The
Skia bitmap is then copied into the graphic buffer using OpenGL ES
to benefit from texture swizzling.
HOW PROCESSES USE THE ATLAS
Whenever a process' hardware renderer initializes its EGL context,
it queries the atlas service for the graphic buffer and the map.
It is important to remember that both the context and the map will
be valid for the lifetime of the hardware renderer (if the system
process goes down, all apps get killed as well.)
Every time the hardware renderer needs to render a bitmap, it first
checks whether the bitmap can be found in the assets atlas. When
the bitmap is part of the atlas, texture coordinates are remapped
appropriately before rendering.
Change-Id: I8eaecf53e7f6a33d90da3d0047c5ceec89ea3af0
