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  3. FCanvas

FCanvas

Encapsulates the canvas state.

Unreal Engine C++ API Reference > Runtime > Engine

References

   
Module Engine
Header /Engine/Source/Runtime/Engine/Public/CanvasTypes.h
Include #include "CanvasTypes.h"

Syntax

class FCanvas

Remarks

Encapsulates the canvas state.

Variables

  Type Name Description
Public variable float AlphaModulate  
Public variable int32 LastElementIndex Store index of last Element off to avoid semi expensive Find()
Public variable TMap< int32, int32 > SortedElementLookupMap Map from sortkey to array index of SortedElements for faster lookup of existing entries
Public variable TArray< FCanvasSortElement > SortedElements Batched canvas elements to be sorted for rendering. Sort order is back-to-front
Public variable TSharedPtr< FCanvasWordWrapper > WordWrapper Private class for handling word wrapping behavior.

Constructors

  Type Name Description
Public function  

FCanvas ( FRenderTarget* InRenderTarget,
FHitProxyConsumer* InHitProxyConsumer,
const FGameTime& Time,
ERHIFeatureLevel::Type InFeatureLevel,
float InDPIScale
)

 Constructor. For situations where a world is not available, but time information is
Public function  

FCanvas ( FRenderTarget* InRenderTarget,
FHitProxyConsumer* InHitProxyConsumer,
UWorld* InWorld,
ERHIFeatureLevel::Type InFeatureLevel,
ECanvasDrawMode DrawMode,
float InDPIScale
)

 Constructor.
Public function FORCEINLINE_DEBUGGABLE

FCanvas ( FRenderTarget* InRenderTarget,
FHitProxyConsumer* InHitProxyConsumer,
float InRealTime,
float InWorldTime,
float InWorldDeltaTime,
ERHIFeatureLevel::Type InFeatureLevel,
float InDPIScale
)

  

Destructors

  Type Name Description
Public function   Destructor.

Functions

  Type Name Description
Public function void

AddTileRenderItem ( float X,
float Y,
float SizeX,
float SizeY,
float U,
float V,
float SizeU,
float SizeV,
const FMaterialRenderProxy* MaterialRenderProxy,
FHitProxyId HitProxyId,
bool bFreezeTime,
FColor InColor
)

 Generates a new FCanvasTileRendererItem for the current sortkey and adds it to the sortelement list of items to render
Public function void

AddTriangleRenderItem ( const FCanvasUVTri& Tri,
const FMaterialRenderProxy* MaterialRenderProxy,
FHitProxyId HitProxyId,
bool bFreezeTime
)

 Generates a new FCanvasTriangleRendererItem for the current sortkey and adds it to the sortelement list of items to render
Public function Static ESimpleElementBlendMode Translate EBlendMode into ESimpleElementBlendMode used by tiles
Public function Static FMatrix

CalcBaseTransform2D ( uint32 ViewSizeX,
uint32 ViewSizeY
)

 Generate a 2D projection for the canvas.
Public function Static FMatrix

CalcBaseTransform3D ( uint32 ViewSizeX,
uint32 ViewSizeY,
float fFOV,
float NearPlane
)

 Generate a 3D projection for the canvas. Use this if you want to transform in 3D
Public function Static FMatrix

CalcProjectionMatrix ( uint32 ViewSizeX,
uint32 ViewSizeY,
float fFOV,
float NearPlane
)

 Generate a projection matrix for the canvas. Used for CalcBaseTransform3D
Public function Static FMatrix

CalcViewMatrix ( uint32 ViewSizeX,
uint32 ViewSizeY,
float fFOV
)

 Generate a view matrix for the canvas. Used for CalcBaseTransform3D
Public function void

Clear ( const FLinearColor& Color
)

 Clear the canvas
Public function void Clear the list of dirty batches that need to be rendered by the canvas
Public function void

CopyTransformStack ( const FCanvas& Copy
)

 Copy the conents of the TransformStack from an existing canvas
Public function Static FCanvas *

Create ( FRDGBuilder& GraphBuilder,
FRDGTextureRef InRenderTarget,
FHitProxyConsumer* InHitProxyConsumer,
const FGameTime& Time,
ERHIFeatureLevel::Type InFeatureLevel,
float InDPIScale
)

  
Public function Static FORCEINLINE_DEBUGGABLEFCanvas *

Create ( FRDGBuilder& GraphBuilder,
FRDGTextureRef InRenderTarget,
FHitProxyConsumer* InHitProxyConsumer,
float InRealTime,
float InWorldTime,
float InWorldDeltaTime,
ERHIFeatureLevel::Type InFeatureLevel,
float InDPIScale
)

  
Public function void

DrawItem ( FCanvasItem& Item
)

 Draw a CanvasItem
Public function void

DrawItem ( FCanvasItem& Item,
const FVector2D& InPosition
)

 Draw a CanvasItem at the given coordinates
Public function void

DrawItem ( FCanvasItem& Item,
float X,
float Y
)

 Draw a CanvasItem at the given coordinates
Public function void

DrawNGon ( const FVector2D& Center,
const FColor& Color,
int32 NumSides,
float Radius
)

  
Public function int32

DrawShadowedString ( double StartX,
double StartY,
FStringView Text,
const UFont* Font,
const FLinearColor& Color,
const FLinearColor& ShadowColor
)

 Draw an string centered on given location.
Public function int32

DrawShadowedText ( double StartX,
double StartY,
const FText& Text,
const UFont* Font,
const FLinearColor& Color,
const FLinearColor& ShadowColor
)

  
Public function void

DrawTile ( double X,
double Y,
double SizeX,
double SizeY,
float U,
float V,
float SizeU,
float SizeV,
const FLinearColor& Color,
const FTexture* Texture,
ESimpleElementBlendMode BlendMode
)

  
Public function void

DrawTile ( double X,
double Y,
double SizeX,
double SizeY,
float U,
float V,
float SizeU,
float SizeV,
const FLinearColor& Color,
const FTexture* Texture,
bool AlphaBlend
)

 Draw arbitrary aligned rectangle.
Public function void

Flush_GameThread ( bool bForce
)

 Sends a message to the rendering thread to draw the batched elements.
Public function void

Flush_RenderThread ( FRHICommandListImmediate& RHICmdList,
bool bForce
)

 Sends a message to the rendering thread to draw the batched elements.
Public function void

Flush_RenderThread ( FRDGBuilder& GraphBuilder,
bool bForce
)

  
Public function Const uint32 Accessor for allowed canvas modes
Public function FBatchedElements *

GetBatchedElements ( EElementType InElementType,
FBatchedElementParameters* InBatchedElementParameters,
const FTexture* Texture,
ESimpleElementBlendMode BlendMode,
const FDepthFieldGlowInfo& GlowInfo,
bool bApplyDPIScale
)

 Returns a FBatchedElements pointer to be used for adding vertices and primitives for rendering.
Public function Const const FMatrix & Get the bottom-most element of the transform stack.
Public function Const float  
Public function Const float  
Public function Const float  
Public function Const float  
Public function Const ERHIFeatureLevel::Type Access current feature level
Public function Const const FMatrix & Get the current top-most transform entry
Public function Const FHitProxyConsumer *  
Public function Const FHitProxyId  
Public function Const FIntPoint  
Public function Const FRenderTarget * Get the current render target for the canvas
Public function Const FSceneInterface *  
Public function Const EShaderPlatform Access current shader platform
Public function FCanvasSortElement &

GetSortElement ( int32 DepthSortKey
)

 Get the sort element for the given sort key. Allocates a new entry if one does not exist
Public function Const const FGameTime &

GetTime ()

 Access gameplay time
Public function Const FMatrix Get the current top-most transform entry without the canvas projection
Public function Const const TArray< FTransformEntry > & Returns the transform stack
Public function Const const FIntRect &  
Public function Const bool Determine if the canvas has dirty batches that need to be rendered
Public function Const bool  
Public function Const bool  
Public function Const bool  
Public function Const bool  
Public function int32 Pop sort key off of the stack.
Public function void Removes the top transform from the canvas's transform stack.
Public function void

PushAbsoluteTransform ( const FMatrix& Transform
)

 Pushes a transform onto the canvas's transform stack.
Public function void

PushDepthSortKey ( int32 InSortKey
)

 Push sort key onto the stack. Rendering is done with the current sort key stack entry.
Public function void

PushRelativeTransform ( const FMatrix& Transform
)

 Pushes a transform onto the canvas's transform stack, multiplying it with the current top of the stack.
Public function void

SetAllowedModes ( uint32 InAllowedModes
)

 Toggle allowed canvas modes
Public function void

SetBaseTransform ( const FMatrix& Transform
)

 Replace the base (ie. TransformStack(0)) transform for the canvas with the given matrix
Public function void

SetHitProxy ( HHitProxy* HitProxy
)

 Sets the hit proxy which will be used for subsequent canvas primitives.
Public function void

SetParentCanvasSize ( FIntPoint InParentSize
)

  
Public function void Sets the render target which will be used for subsequent canvas primitives.
Public function void

SetRenderTargetDirty ( bool bDirty
)

 Marks render target as dirty so that it will be resolved to texture
Public function void

SetRenderTargetRect ( const FIntRect& ViewRect
)

 Sets a rect that should be used to offset rendering into the viewport render target If not set the canvas will render to the full target
Public function void

SetRenderTargetScissorRect ( const FIntRect& ScissorRect
)

 The clipping rectangle used when rendering this canvas
Public function void

SetScaledToRenderTarget ( bool bScale
)

  
Public function void

SetStereoRendering ( bool bStereo
)

  
Public function void

SetUseInternalTexture ( const bool bInUseInternalTexture
)

  
Public function int32 Return top sort key of the stack.
Public function void

WrapString ( FTextSizingParameters& Parameters,
const float InCurX,
FStringView Text,
TArray< FWrappedStringElement >& out_Lines,
FCanvasWordWrapper::FWrappedLineData*const OutWrappedLineData
)

  

Classes

  Type Name Description
Public class FCanvasSortElement Contains all of the batched elements that need to be rendered at a certain depth sort key  
Public class FTransformEntry Entry for the transform stack which stores a matrix and its CRC for faster comparisons  

Enums

  Type Name Description
Public enum ECanvasAllowModes Enum for canvas features that are allowed  
Public enum ECanvasDrawMode    
Public enum EElementType Enum that describes what type of element we are currently batching.  

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