BufferViewport

public class BufferViewport

Encapsulated information about where to find the data in the client's target for a given region (e.g., the region for a particular eye).

This includes the viewport bounds for that region, the field of view, and the type of eye that has been rendered. This latter is used to calculate what kind of distortion to apply when the region is distorted to the screen.

A BufferViewport instance can be created via GvrApi, and populated via BufferViewportList.

Nested Classes

class	BufferViewport.EyeType		The type of eye corresponding to the BufferViewport.
class	BufferViewport.Reprojection		Types of asynchronous reprojection.

Constants

int	BUFFER_INDEX_EXTERNAL_SURFACE	Source buffer index that indicates that the viewport contents should be taken directly from its external surface rather than from one of the frame's buffers.
int	EXTERNAL_SURFACE_ID_NONE	External surface ID that represents a nonexistent surface.

Public Methods

boolean	equals(Object other)
int	getExternalSurfaceId() Gets the GvrLayout issued Surface ID.
float	getOpacity() Gets the opacity to apply to the specified viewport.
int	getReprojection() Gets the type of reprojection to perform on the viewport.
int	getSourceBufferIndex() Gets the index of the source buffer that contains the viewport's pixels.
void	getSourceFov(RectF sourceFovOut) Gets the eye's field of view in degrees.
void	getSourceUv(RectF sourceUvOut) Gets the UV coordinates within the buffer where this viewport's pixels are located.
int	getTargetEye() Gets the BufferViewport.EyeType for the viewport.
void	getTransform(float[] transform) Gets the matrix that transforms a quad with vertices (-1, -1, 0), (1, -1, 0), (-1, 1, 0), (1, 1, 0) representing the viewport contents to its desired position in eye space for the target eye.
void	setExternalSurfaceId(int id) Sets the ID of the externally-managed Surface texture from which this viewport reads.
void	setOpacity(float opacity) Sets the opacity to apply to the specified viewport.
void	setReprojection(int reprojection) Sets the type of reprojection to perform on the viewport.
void	setSourceBufferIndex(int index) Sets the index of the source buffer that contains the viewport's pixels.
void	setSourceFov(RectF sourceFov) Sets the eye's field of view in degrees.
void	setSourceLayer(int layerIndex) Sets the layer in a multiview buffer from which the viewport should sample.
void	setSourceUv(RectF sourceUv) Sets the UV range within the buffer where this viewport's pixels are located.
void	setTargetEye(int eye) Sets the BufferViewport.EyeType for the viewport.
void	setTransform(float[] transform) Sets the matrix that transforms a quad with vertices (-1, -1, 0), (1, -1, 0), (-1, 1, 0), (1, 1, 0) that represents the viewport contents to its correct position in eye space for the target eye.
void	shutdown() Shuts down the BufferViewport instance, freeing associated resources.

Inherited Methods

From class java.lang.Object

boolean	equals(Object arg0)
final Class<?>	getClass()
int	hashCode()
final void	notify()
final void	notifyAll()
String	toString()
final void	wait(long arg0, int arg1)
final void	wait(long arg0)
final void	wait()

Constants

public static final int BUFFER_INDEX_EXTERNAL_SURFACE

Source buffer index that indicates that the viewport contents should be taken directly from its external surface rather than from one of the frame's buffers.

Constant Value: -1

public static final int EXTERNAL_SURFACE_ID_NONE

External surface ID that represents a nonexistent surface.

Constant Value: -1

Public Methods

public boolean equals (Object other)

Parameters

other

public int getExternalSurfaceId ()

Gets the GvrLayout issued Surface ID. EXTERNAL_SURFACE_ID_NONE if no Surface is set.

Returns

• The ID of the externally-managed surface.

public float getOpacity ()

Gets the opacity to apply to the specified viewport.

Returns

• Opacity Defaults to 1.

public int getReprojection ()

Gets the type of reprojection to perform on the viewport.

Returns

• Type of reprojection (see BufferViewport.Reprojection) that is applied to the viewport.

public int getSourceBufferIndex ()

Gets the index of the source buffer that contains the viewport's pixels.

public void getSourceFov (RectF sourceFovOut)

Gets the eye's field of view in degrees.

Parameters

sourceFovOut	The rect to populate with the eye's field-of-view.

public void getSourceUv (RectF sourceUvOut)

Gets the UV coordinates within the buffer where this viewport's pixels are located.

Parameters

sourceUvOut	The rect to populate with the current source UV coordinates.

public int getTargetEye ()

Gets the BufferViewport.EyeType for the viewport.

public void getTransform (float[] transform)

Gets the matrix that transforms a quad with vertices (-1, -1, 0), (1, -1, 0), (-1, 1, 0), (1, 1, 0) representing the viewport contents to its desired position in eye space for the target eye.

Parameters

transform	The array in which the transform matrix should be returned.

public void setExternalSurfaceId (int id)

Sets the ID of the externally-managed Surface texture from which this viewport reads.

Parameters

id	The ID of the external surface, as assigned by GvrLayout. A value of EXTERNAL_SURFACE_ID_NONE will disable use of the external surface.

public void setOpacity (float opacity)

Sets the opacity to apply to the specified viewport.

Parameters

opacity	The opacity that will be applied to the viewport, it should be within [0,1].

public void setReprojection (int reprojection)

Sets the type of reprojection to perform on the viewport. Viewports that display world content should use full reprojection. Viewports that display head-locked UI should disable reprojection to avoid excessive judder. The default is to perform full reprojection.

Parameters

reprojection	Type of reprojection (see BufferViewport.Reprojection) that will be applied to the viewport.

public void setSourceBufferIndex (int index)

Sets the index of the source buffer that contains the viewport's pixels.

Parameters

index	The new buffer index. This is either an index into the array of BufferSpec objects passed when creating the swap chain or BUFFER_INDEX_EXTERNAL_SURFACE when an external surface is used as the image source.

public void setSourceFov (RectF sourceFov)

Sets the eye's field of view in degrees.

Parameters

sourceFov	The new field of view.

public void setSourceLayer (int layerIndex)

Sets the layer in a multiview buffer from which the viewport should sample.

Parameters

layerIndex	The layer in the array texture that distortion samples from. Must be non-negative. Defaults to 0.

public void setSourceUv (RectF sourceUv)

Sets the UV range within the buffer where this viewport's pixels are located.

Parameters

sourceUv	The rect with new source UV coordinates. The coordinates must satisfy left <= right and bottom <= top.

public void setTargetEye (int eye)

Sets the BufferViewport.EyeType for the viewport.

Parameters

eye

public void setTransform (float[] transform)

Sets the matrix that transforms a quad with vertices (-1, -1, 0), (1, -1, 0), (-1, 1, 0), (1, 1, 0) that represents the viewport contents to its correct position in eye space for the target eye. This is a more general version of setSourceFov.

Parameters

transform	The new projection matrix to set.

public void shutdown ()

Shuts down the BufferViewport instance, freeing associated resources.

Note: The caller is responsible for ensuring that this BufferViewport isn't used after shutdown.