CanvasFrontBufferedRenderer
@RequiresApi(value = 29)
public final class CanvasFrontBufferedRenderer<T extends Object>
Class responsible for supporting a "front buffered" rendering system. This allows for lower latency graphics by leveraging a combination of front buffered and multi buffered content layers. Active content is rendered first into the front buffered layer which is simultaneously being presented to the display. Periodically content is rendered into the multi buffered layer which will have more traditional latency guarantees, however, minimizes the impact of visual artifacts due to graphical tearing.
Summary
Nested types |
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public interface CanvasFrontBufferedRenderer.Callback<T extends Object>Provides callbacks for consumers to draw into the front and multi buffered layers as well as provide opportunities to synchronize |
Public constructors |
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<T extends Object> CanvasFrontBufferedRenderer( |
Public methods |
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final void |
cancel()Requests to cancel rendering and hides the front buffered layer. |
final void |
clear()Clears the contents of both the front and multi buffered layers. |
final void |
commit()Requests to render the entire scene to the multi buffered layer and schedules a call to |
final int |
format of the underlying buffers being rendered into by |
final @NonNull ColorSpace |
Configures the |
final boolean |
isValid()Determines whether or not the |
final void |
Releases the |
final void |
renderFrontBufferedLayer(@NonNull T param)Render content to the front buffered layer providing optional parameters to be consumed in |
final void |
renderMultiBufferedLayer(@NonNull Collection<@NonNull T> params)Requests to render to the multi buffered layer. |
final void |
setColorSpace(@NonNull ColorSpace colorSpace)Configures the |
Public constructors
CanvasFrontBufferedRenderer
public <T extends Object> CanvasFrontBufferedRenderer(
@NonNull SurfaceView surfaceView,
@NonNull CanvasFrontBufferedRenderer.Callback<@NonNull T> callback,
int bufferFormat
)
| Parameters | |
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@NonNull SurfaceView surfaceView |
Target SurfaceView to act as the parent rendering layer for multi buffered content |
@NonNull CanvasFrontBufferedRenderer.Callback<@NonNull T> callback |
Callbacks used to render into front and multi buffered layers as well as configuring |
int bufferFormat |
format of the underlying buffers being rendered into by |
Public methods
cancel
public final void cancel()
Requests to cancel rendering and hides the front buffered layer. Unlike commit, this does not schedule a call to render into the multi buffered layer. This is useful in palm rejection use cases, where some initial touch events might be processed before a corresponding cancel event is received indicating the touch gesture is coming from a palm rather than intentional user input. In the case where MotionEvent#getAction returns ACTION_CANCEL, this is to be invoked.
If this GLFrontBufferedRenderer has been released, that is isValid returns false, this call is ignored.
clear
public final void clear()
Clears the contents of both the front and multi buffered layers. This triggers a call to Callback.onMultiBufferedLayerRenderComplete and hides the front buffered layer.
commit
public final void commit()
Requests to render the entire scene to the multi buffered layer and schedules a call to Callback.onDrawMultiBufferedLayer. The parameters provided to Callback.onDrawMultiBufferedLayer will include each argument provided to every renderFrontBufferedLayer call since the last call to commit has been made. When rendering to the multi-buffered layer is complete, this synchronously hides the front buffer and updates the multi buffered layer.
If this CanvasFrontBufferedRenderer has been released, that is isValid returns false, this call is ignored.
getBufferFormat
public final int getBufferFormat()
format of the underlying buffers being rendered into by CanvasFrontBufferedRenderer. The particular valid combinations for a given Android version and implementation should be documented by that version. HardwareBuffer.RGBA_8888 and HardwareBuffer.RGBX_8888 are guaranteed to be supported. However, consumers are recommended to query the desired HardwareBuffer configuration using HardwareBuffer.isSupported. The default is HardwareBuffer.RGBA_8888.
getColorSpace
public final @NonNull ColorSpace getColorSpace()
Configures the ColorSpace that the content should be rendered with for the front and multi buffered layers. This parameter is only consumed on Android U and above. For older API levels this is ignored.
isValid
public final boolean isValid()
Determines whether or not the CanvasFrontBufferedRenderer is in a valid state. That is the release method has not been called. If this returns false, then subsequent calls to renderFrontBufferedLayer, renderMultiBufferedLayer, commit, and release are ignored
| Returns | |
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boolean |
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release
public final void release(boolean cancelPending, Function0<Unit> onReleaseComplete)
Releases the CanvasFrontBufferedRenderer. In process requests are ignored. If the CanvasFrontBufferedRenderer is already released, that is isValid returns false, this method does nothing.
renderFrontBufferedLayer
public final void renderFrontBufferedLayer(@NonNull T param)
Render content to the front buffered layer providing optional parameters to be consumed in Callback.onDrawFrontBufferedLayer. Additionally the parameter provided here will also be consumed in Callback.onDrawMultiBufferedLayer when the corresponding commit method is invoked, which will include all params in each call made to this method up to the corresponding commit call.
If this CanvasFrontBufferedRenderer has been released, that is isValid returns false, this call is ignored.
| Parameters | |
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@NonNull T param |
Optional parameter to be consumed when rendering content into the commit layer |
renderMultiBufferedLayer
public final void renderMultiBufferedLayer(@NonNull Collection<@NonNull T> params)
Requests to render to the multi buffered layer. This schedules a call to Callback.onDrawMultiBufferedLayer with the parameters provided. If the front buffered layer is visible, this will hide this layer after rendering to the multi buffered layer is complete. This is equivalent to calling CanvasFrontBufferedRenderer.renderFrontBufferedLayer for each parameter provided in the collection followed by a single call to CanvasFrontBufferedRenderer.commit. This is useful for re-rendering the multi buffered scene when the corresponding Activity is being resumed from the background in which the contents should be re-drawn. Additionally this allows for applications to decide to dynamically render to either front or multi buffered layers.
If this CanvasFrontBufferedRenderer has been released, that is isValid returns 'false', this call is ignored.
| Parameters | |
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@NonNull Collection<@NonNull T> params |
Parameters that to be consumed when rendering to the multi buffered layer. These parameters will be provided in the corresponding call to |
setColorSpace
public final void setColorSpace(@NonNull ColorSpace colorSpace)
Configures the ColorSpace that the content should be rendered with for the front and multi buffered layers. This parameter is only consumed on Android U and above. For older API levels this is ignored.