HardwareBufferRenderer
open class HardwareBufferRenderer : AutoCloseable
| kotlin.Any | |
| ↳ | android.graphics.HardwareBufferRenderer |
Creates an instance of a hardware-accelerated renderer. This is used to render a scene built from RenderNodes to an output HardwareBuffer. There can be as many HardwareBufferRenderer instances as desired.
Resources & lifecycle
All HardwareBufferRenderer and HardwareRenderer instances share a common render thread. Therefore HardwareBufferRenderer will share common resources and GPU utilization with hardware accelerated rendering initiated by the UI thread of an application. The render thread contains the GPU context & resources necessary to do GPU-accelerated rendering. As such, the first HardwareBufferRenderer created comes with the cost of also creating the associated GPU contexts, however each incremental HardwareBufferRenderer thereafter is fairly cheap. The expected usage is to have a HardwareBufferRenderer instance for every active HardwareBuffer.
RenderNodes can be consumed directly by the system compositor through SurfaceControl.Transaction#setBuffer(SurfaceControl, HardwareBuffer). HardwareBufferRenderer will never clear contents before each draw invocation so previous contents in the HardwareBuffer target will be preserved across renders.
Summary
| Nested classes | |
|---|---|
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Sets the parameters that can be used to control a render request for a |
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Class that contains data regarding the result of the render request. |
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| Public constructors | |
|---|---|
HardwareBufferRenderer(buffer: HardwareBuffer)Creates a new instance of |
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| Public methods | |
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| open Unit |
close()Releases the resources associated with this |
| open Boolean |
isClosed()Returns if the |
| open HardwareBufferRenderer.RenderRequest |
Returns a |
| open Unit |
setContentRoot(content: RenderNode?)Sets the content root to render. |
| open Unit |
setLightSourceAlpha(ambientShadowAlpha: Float, spotShadowAlpha: Float)Configures the ambient & spot shadow alphas. |
| open Unit |
setLightSourceGeometry(lightX: Float, lightY: Float, lightZ: Float, lightRadius: Float)Sets the center of the light source. |
Public constructors
HardwareBufferRenderer
HardwareBufferRenderer(buffer: HardwareBuffer)
Creates a new instance of HardwareBufferRenderer with the provided HardwareBuffer as the output of the rendered scene.
| Parameters | |
|---|---|
buffer |
HardwareBuffer: This value cannot be null. |
Public methods
close
open fun close(): Unit
Releases the resources associated with this HardwareBufferRenderer instance. **Note** this does not call HardwareBuffer#close() on the provided HardwareBuffer instance
| Exceptions | |
|---|---|
java.lang.Exception |
if this resource cannot be closed |
isClosed
open fun isClosed(): Boolean
Returns if the HardwareBufferRenderer has already been closed. That is HardwareBufferRenderer#close() has been invoked.
| Return | |
|---|---|
Boolean |
True if the HardwareBufferRenderer has been closed, false otherwise. |
obtainRenderRequest
open fun obtainRenderRequest(): HardwareBufferRenderer.RenderRequest
Returns a RenderRequest that can be used to render into the provided HardwareBuffer. This is used to synchronize the RenderNode content provided by setContentRoot(android.graphics.RenderNode).
| Return | |
|---|---|
HardwareBufferRenderer.RenderRequest |
An instance of RenderRequest. The instance may be reused for every frame, so the caller should not hold onto it for longer than a single render request. This value cannot be null. |
setContentRoot
open fun setContentRoot(content: RenderNode?): Unit
Sets the content root to render. It is not necessary to call this whenever the content recording changes. Any mutations to the RenderNode content, or any of the RenderNodes contained within the content node, will be applied whenever a new RenderRequest is issued via obtainRenderRequest() and RenderRequest#draw(Executor,.
| Parameters | |
|---|---|
content |
RenderNode?: The content to set as the root RenderNode. If null the content root is removed and the renderer will draw nothing. |
setLightSourceAlpha
open fun setLightSourceAlpha(
ambientShadowAlpha: Float,
spotShadowAlpha: Float
): Unit
Configures the ambient & spot shadow alphas. This is the alpha used when the shadow has max alpha, and ramps down from the values provided to zero.
These values are typically provided by the current theme, see android.R.attr#spotShadowAlpha and android.R.attr#ambientShadowAlpha.
This must be set at least once along with setLightSourceGeometry(float,float,float,float) before shadows will work.
| Parameters | |
|---|---|
ambientShadowAlpha |
Float: The alpha for the ambient shadow. If unsure, a reasonable default is 0.039f. Value is between 0.0f and 1.0f inclusive |
spotShadowAlpha |
Float: The alpha for the spot shadow. If unsure, a reasonable default is 0.19f. Value is between 0.0f and 1.0f inclusive |
setLightSourceGeometry
open fun setLightSourceGeometry(
lightX: Float,
lightY: Float,
lightZ: Float,
lightRadius: Float
): Unit
Sets the center of the light source. The light source point controls the directionality and shape of shadows rendered by RenderNode Z & elevation.
The light source should be setup both as part of initial configuration, and whenever the window moves to ensure the light source stays anchored in display space instead of in window space.
This must be set at least once along with setLightSourceAlpha(float,float) before shadows will work.
| Parameters | |
|---|---|
lightX |
Float: The X position of the light source. If unsure, a reasonable default is 'displayWidth / 2f - windowLeft'. |
lightY |
Float: The Y position of the light source. If unsure, a reasonable default is '0 - windowTop' |
lightZ |
Float: The Z position of the light source. Must be >= 0. If unsure, a reasonable default is 600dp. Value is 0f or greater |
lightRadius |
Float: The radius of the light source. Smaller radius will have sharper edges, larger radius will have softer shadows. If unsure, a reasonable default is 800 dp. Value is 0f or greater |