Path ops can be used to combine two paths instances in a single path
object. The following operations can be used:
- Difference
- Reverse difference
- Union
- XOR
- Intersection
To use the API:
Path p1 = createCircle();
Path p2 = createRect();
Path result = new Path();
result.op(p1, p2, Path.Op.DIFFERENCE);
This code will subtract the rectangle from the circle and generate
the resulting path in "result."
Change-Id: Ic25244665b6691a7df0b0002a09da73d937b553b
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
If a perspective transform is set on the Canvas, drawText() should
not attempt to rasterize glyphs in screen space. This change uses
the old behavior instead (i.e. rasterize the glyphs at the native
font size and apply the transform on the resulting mesh.)
This change also adds an optimization: empty glyphs (spaces) do
not generate vertices anymore. This saves a lot of vertices in text
heavy applications such as Gmail.
Change-Id: Ib531384163f5165b5785501612a7b1474f3ff599
The new UI works just like ApiDemos. The label of the activities
declared in the manifest defines where they go in the UI.
For instance Draw/Circles will create an entry called Draw in the
first screen of the test app. Click the "Draw" item will launch
a new activity containing an item called "Circles".
Change-Id: I98a4442ee3d992598af440b2078ae1925214da20
This change does not apply to drawPosText() and drawTextOnPath() yet.
Prior to this change, glyphs were always rasterized based on the
font size specified in the paint. All transforms were then applied
on the resulting texture. This creates rather ugly results when
text is scaled and/or rotated.
With this change, the font renderer will apply the current transform
matrix to the glyph before they are rasterized. This generates much
better looking results.
Change-Id: I0141b6ff18db35e1213e7a3ab9db1ecaf03d7a9c
Bug #7146141
When non-rectangular clipping occurs in a layer the render buffer
used as the stencil buffer is not cached. If this happens on a
View's hardware layer the render buffer will live for as long
as the layer is bound to the view. When a stencil buffer is
required because of a call to Canvas.saveLayer() it will be allocated
on every frame. A future change will address this problem.
If "show GPU overdraw" is enabled, non-rectangular clips are not
supported anymore and we fall back to rectangular clips instead.
This is a limitation imposed by OpenGL ES that cannot be worked
around at this time.
This change also improves the Matrix4 implementation to easily
detect when a rect remains a rect after transform.
Change-Id: I0e69fb901792d38bc0c4ca1bf9fdb02d7db415b9
Bug #7353771
This API can be used when scaling large images down to a small size
to get nicer looking results.
Change-Id: If09087eed36077eee5355f6047a3ca67747d7d9e
The pixel store pack alignment was not set for the source texture,
causing a write to occur outside of the destination bitmap's
bounds.
Change-Id: Iaa5767acf7b5943fbc2765c3810a142f06b1a796
There are two fixes here:
- precaching: instead of caching-then-drawing whenever there is a new
glyph, we cache at DisplayList record time. Then when we finally draw that
DisplayList, we just upload the affected texture(s) once, instead of once
per change. This is a huge savings in upload time, especially when there are
larger glyphs being used by the app.
- packing: Previously, glyphs would line up horizontally on each cache line, leaving
potentially tons of space vertically, especially when smaller glyphs got put into cache
lines intended for large glyphs (which can happen when an app uses lots of unique
glyphs, a common case with, for example, chinese/japanese/korean languages). The new
approach packs glyphs vertically as well as horizontally to use the space more efficiently
and provide space for more glyphs in these situations.
Change-Id: I84338aa25db208c7bf13f3f92b4d05ed40c33527
An optimization for paths is to only create a texture for the original native
Path object, and have all copies of that object use that texture. This works in
most cases, but sometimes that original path object may get destroyed (when the
SDK path object is finalized) while we are still referencing and using that object
in the DisplayList code. This causes undefined errors such as crashes and hanging
as we iterate through the operations of a destroyed (and garbage-filled) path object.
The fix is to use the existing ResourceCache to refcount the original path until
we are done with it.
Issue #6414050 Analytics Dogfood App crashes reliably on Jellybean
Change-Id: I5dbec5c069f7d6a1e68c13424f454976a7d188e9
A bug in the invalidation logic meant that changes to a view
would not cause parents in the view hiearchy that were set to have
a layer (e.g., View.LAYER_TYPE_HARDWARE) to get invalidated properly.
So even though the child view was all set to recreate its display list
according to the property change, the layer in the tree above it would stay
as-is, meaning that the change would not show up on the screen.
Issue #5887530 DropTarget text does not change color with the icon
Change-Id: Ie6eac4f406d172cb437822d9fe76340ab2afaf1c
Some views (such as ImageView and TextView) handle non-opaque alpha
values directly. This was originally an optimization, but we can handle it faster
in many cases without this optimization when DisplayList properties are enabled.
Basically, if a view has non-overlapping rendering, we set the alpha value directly
on the renderer (the equivalent of setting it on the Paint object) and draw each
primitive with that alpha value. Doing it this way avoids re-creating DisplayLists
while getting the same speedup that onSetAlpha() used to get pre-DisplayList properties.
Change-Id: I0f7827f075d3b35093a882d4adbb300a1063c288
Re-enabling DisplayList properties last week caused some app
errors due to the way that some transforms were being handled (specifically,
those coming from the old Animations and ViewGroup's childStaticTransformation
field). This change pushes *all* transform/alpha data from View.draw() into
the view's DisplayList, making DisplayLists more encapsulated (and correct).
Change-Id: Ia702c6aae050784bb3ed505aa87553113f8a1938
This adds basic support for clip regions. It is currently disabled at compile
time. Enabling clip regions will require setting up a stencil buffer.
Change-Id: I638616a972276e38737f8ac0633692c3845eaa74
The render threat is likely to break your application if you initiate it.
As such it must be explicitely requested using the following meta-data
tag in your manifest's application tag:
<meta-data android:name="android.graphics.renderThread" android:value="true" />
Change-Id: Ibf0a48af2a0d091562bf6907eac970e3d1d601c4
This could cause the draw() code of views to be invoked too often
or worse, called with the wrong canvas. For instance, a view backed
by a software layer could get its draw() method called to record a
display list. Using a software layer is the recommended way to use
drawing operations not supported in hardware. Since we would
sometimes call the draw() method with the hardware backend anyway,
the app could crash by executing an unsupported operation.
Change-Id: Ib5f9a3a4c6f3efff5e0162ecd73d2dffe06e30a6
This method is invoked by TextureView.getBitmap() and failures must be
caught to avoid leaving the GL context in a potentially bad state.
Change-Id: I620de395ba1bc20154de58c81963223dc55cac78
The previous implementation was using glBlendFunc with the parameters
GL_ZERO/GL_ZERO which doesn't work for text, paths and other alpha
sources (anti-aliasing.) The correct implementation is GL_ZERO/
GL_ONE_MINUS_SRC_ALPHA.
Change-Id: I4cca65e57b6a37bbf5a41d382cb0648ee8e11e79
Bug #4343984
TextureView can be used to render media content (video, OpenGL,
RenderScript) inside a View.
The key difference with SurfaceView is that TextureView does
not create a new Surface. This gives the ability to seamlessly
transform, animate, fade, etc. a TextureView, which was hard
if not impossible to do with a SurfaceView.
A TextureView also interacts perfectly with ScrollView,
ListView, etc. It allows application to embed media content
in a much more flexible way than before.
For instance, to render the camera preview at 50% opacity,
all you need to do is the following:
mTextureView.setAlpha(0.5f);
Camera c = Camera.open();
c.setPreviewTexture(mTextureView.getSurfaceTexture());
c.startPreview();
TextureView uses a SurfaceTexture to get the job done. More
APIs are required to make it easy to create OpenGL contexts
for a TextureView. It can currently be done with a bit of
JNI code.
Change-Id: Iaa7953097ab5beb8437bcbbfa03b2df5b7f80cd7
All accelerated lines are now rendered as quads. Hairlines used to
be rendered as GL_LINES, but these lines don't render the same as our
non-accelerated lines, so we're using quads for everything. Also, fixed
a bug in the way that we were offsetting quads (and not offseting points)
to ensure that our lines/points actuall start on the same pixels as
Skia's.
Change-Id: I51b923cc08a9858444c430ba07bc8aa0c83cbe6a
