Class BufferedRTHandleSystem

Implement a multiple buffering for RenderTextures.

Inheritance
object
BufferedRTHandleSystem
Implements
Inherited Members
Namespace: UnityEngine.Rendering
Assembly: Unity.RenderPipelines.Core.Runtime.dll
Syntax
public class BufferedRTHandleSystem : IDisposable
Examples
enum BufferType
{
    Color,
    Depth
}

void Render()
{
    var camera = GetCamera();
    var buffers = GetFrameHistoryBuffersFor(camera);

    // Set reference size in case the rendering size changed this frame
    buffers.SetReferenceSize(
        GetCameraWidth(camera), GetCameraHeight(camera),
        GetCameraUseMSAA(camera), GetCameraMSAASamples(camera)
    );
    buffers.Swap();

    var currentColor = buffer.GetFrameRT((int)BufferType.Color, 0);
    if (currentColor == null) // Buffer was not allocated
    {
        buffer.AllocBuffer(
            (int)BufferType.Color,      // Color buffer id
            ColorBufferAllocator,       // Custom functor to implement allocation
            2                           // Use 2 RT for this buffer for double buffering
        );
        currentColor = buffer.GetFrameRT((int)BufferType.Color, 0);
    }

    var previousColor = buffers.GetFrameRT((int)BufferType.Color, 1);

    // Use previousColor and write into currentColor
}

Properties

maxHeight

Maximum allocated height of the Buffered RTHandle System

Declaration
public int maxHeight { get; }
Property Value
Type Description
int

maxWidth

Maximum allocated width of the Buffered RTHandle System

Declaration
public int maxWidth { get; }
Property Value
Type Description
int

rtHandleProperties

Current properties of the Buffered RTHandle System

Declaration
public RTHandleProperties rtHandleProperties { get; }
Property Value
Type Description
RTHandleProperties

Methods

AllocBuffer(int, Func<RTHandleSystem, int, RTHandle>, int)

Allocate RT handles for a buffer.

Declaration
public void AllocBuffer(int bufferId, Func<RTHandleSystem, int, RTHandle> allocator, int bufferCount)
Parameters
Type Name Description
int bufferId

The buffer to allocate.
Func<RTHandleSystem, int, RTHandle> allocator

The functor to use for allocation.
int bufferCount

The number of RT handles for this buffer.

AllocBuffer(int, int, ref RenderTextureDescriptor, FilterMode, TextureWrapMode, bool, int, float, string)

Allocate RT handles for a buffer using a RenderTextureDescriptor.

Declaration
public void AllocBuffer(int bufferId, int bufferCount, ref RenderTextureDescriptor descriptor, FilterMode filterMode = FilterMode.Point, TextureWrapMode wrapMode = TextureWrapMode.Repeat, bool isShadowMap = false, int anisoLevel = 1, float mipMapBias = 0, string name = "")
Parameters
Type Name Description
int bufferId

The buffer to allocate.
int bufferCount

The number of RT handles for this buffer.
RenderTextureDescriptor descriptor

RenderTexture descriptor of the RTHandles.
FilterMode filterMode

Filtering mode of the RTHandles.
TextureWrapMode wrapMode

Addressing mode of the RTHandles.
bool isShadowMap

Set to true if the depth buffer should be used as a shadow map.
int anisoLevel

Anisotropic filtering level.
float mipMapBias

Bias applied to mipmaps during filtering.
string name

Name of the RTHandle.

CalculateRatioAgainstMaxSize(int, int)

Returns the ratio against the current target's max resolution

Declaration
public Vector2 CalculateRatioAgainstMaxSize(int width, int height)
Parameters
Type Name Description
int width

width to utilize
int height

height to utilize
Returns
Type Description
Vector2

retruns the width,height / maxTargetSize.xy ratio.

ClearBuffers(CommandBuffer)

Clears all the previously created history buffers

Declaration
public void ClearBuffers(CommandBuffer cmd)
Parameters
Type Name Description
CommandBuffer cmd

Defines the command buffer used for clearing.

Dispose()

Dispose implementation

Declaration
public void Dispose()

GetFrameRT(int, int)

Return the frame RT or null.

Declaration
public RTHandle GetFrameRT(int bufferId, int frameIndex)
Parameters
Type Name Description
int bufferId

Defines the buffer to use.
int frameIndex

Defines which frame to access within the buffer.
Returns
Type Description
RTHandle

The frame RT or null when the bufferId was not previously allocated (AllocBuffer(int, Func<RTHandleSystem, int, RTHandle>, int)).

GetNumFramesAllocated(int)

Queries the number of RT handle buffers allocated for a buffer ID.

Declaration
public int GetNumFramesAllocated(int bufferId)
Parameters
Type Name Description
int bufferId

The buffer ID to query.
Returns
Type Description
int

The num of frames allocated

ReleaseAll()

Deallocate and clear all buffers.

Declaration
public void ReleaseAll()

ReleaseBuffer(int)

Release a buffer

Declaration
public void ReleaseBuffer(int bufferId)
Parameters
Type Name Description
int bufferId

Id of the buffer that needs to be released.

ResetReferenceSize(int, int)

Reset the reference size of the system and reallocate all textures.

Declaration
public void ResetReferenceSize(int width, int height)
Parameters
Type Name Description
int width

New width.
int height

New height.

SwapAndSetReferenceSize(int, int)

Swap buffers Set the reference size for this RT Handle System (SetReferenceSize(int, int, bool))

Declaration
public void SwapAndSetReferenceSize(int width, int height)
Parameters
Type Name Description
int width

The width of the RTs of this buffer.
int height

The height of the RTs of this buffer.

Implements

Extension Methods