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  3. FCanvas

FCanvas

Encapsulates the canvas state.

API > API/Runtime > API/Runtime/Engine

Encapsulates the canvas state.

   
Name FCanvas
Type class
Header File /Engine/Source/Runtime/Engine/Public/CanvasTypes.h
Include Path #include "CanvasTypes.h"

Syntax

class FCanvas

Constructors

Name Remarks Include Path Unreal Specifiers

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

 Constructor. CanvasTypes.h  

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 CanvasTypes.h  

Destructors

Name Remarks Include Path Unreal Specifiers

~FCanvas()

 Destructor. CanvasTypes.h  

Classes

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

Enums

Public

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

Variables

Public

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

Protected

Name Type Remarks Include Path Unreal Specifiers
AllowedModes uint32 Toggles for various canvas rendering functionality CanvasTypes.h  
bRenderTargetDirty bool True if the render target has been rendered to since last calling SetRenderTarget() CanvasTypes.h  
bScaledToRenderTarget bool True, if Canvas should be scaled to whole render target CanvasTypes.h  
bStereoRendering bool True, if Canvas should be rendered in stereo CanvasTypes.h  
bUseInternalTexture bool True, if Canvas is being rendered in its own texture CanvasTypes.h  
bWriteDestinationAlpha bool True, if the destination alpha channel must be written CanvasTypes.h  
CurrentHitProxy TRefCountPtr< HHitProxy > Current hit proxy object CanvasTypes.h  
DepthSortKeyStack TArray< int32 > Stack of SortKeys. All rendering is done using the top most sort key CanvasTypes.h  
DPIScale float   CanvasTypes.h  
DrawMode ECanvasDrawMode   CanvasTypes.h  
FeatureLevel ERHIFeatureLevel::Type Feature level that we are currently rendering with CanvasTypes.h  
HitProxyConsumer FHitProxyConsumer * Current hit proxy consumer CanvasTypes.h  
ParentSize FIntPoint   CanvasTypes.h  
RenderTarget FRenderTarget * Current render target used by the canvas CanvasTypes.h  
Scene FSceneInterface * Optional scene for rendering. CanvasTypes.h  
ScissorRect FIntRect Scissor rect for the render target CanvasTypes.h  
Time FGameTime Current gameplay time CanvasTypes.h  
TransformStack TArray< FTransformEntry > Stack of matrices. Bottom most entry is the canvas projection CanvasTypes.h  
ViewRect FIntRect View rect for the render target CanvasTypes.h  

Functions

Public

Name Remarks Include Path Unreal Specifiers

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 CanvasTypes.h  

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 CanvasTypes.h  

void Clear ( const FLinearColor& Color
)

 Clear the canvas CanvasTypes.h  

void ClearBatchesToRender()

 Clear the list of dirty batches that need to be rendered by the canvas CanvasTypes.h  

void CopyTransformStack ( const FCanvas& Copy
)

 Copy the conents of the TransformStack from an existing canvas CanvasTypes.h  

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

 Draw a CanvasItem at the given coordinates CanvasTypes.h  

void DrawItem ( FCanvasItem& Item,
const FVector2D& InPosition
)

 Draw a CanvasItem at the given coordinates CanvasTypes.h  

void DrawItem ( FCanvasItem& Item
)

 Draw a CanvasItem CanvasTypes.h  

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

   CanvasTypes.h  

int32 DrawShadowedString ( double StartX,
double StartY,
FStringView Text,
const UFont* Font,
const FLinearColor& Color,
const FLinearColor& ShadowColor
)

 Draw an string centered on given location. CanvasTypes.h  

int32 DrawShadowedText ( double StartX,
double StartY,
const FText& Text,
const UFont* Font,
const FLinearColor& Color,
const FLinearColor& ShadowColor
)

   CanvasTypes.h  

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
)

   CanvasTypes.h  

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. CanvasTypes.h  

void Flush_GameThread ( bool bForce
)

 Sends a message to the rendering thread to draw the batched elements. CanvasTypes.h  

void Flush_RenderThread ( FRHICommandListImmediate& RHICmdList,
bool bForce
)

 Sends a message to the rendering thread to draw the batched elements. CanvasTypes.h  

void Flush_RenderThread ( FRDGBuilder& GraphBuilder,
bool bForce
)

   CanvasTypes.h  

uint32 GetAllowedModes()

 Accessor for allowed canvas modes CanvasTypes.h  

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. CanvasTypes.h  

const FMatrix & GetBottomTransform()

 Get the bottom-most element of the transform stack. CanvasTypes.h  

float GetDPIScale()

   CanvasTypes.h  

ERHIFeatureLevel::Type GetFeatureLevel()

 Access current feature level CanvasTypes.h  

const FMatrix & GetFullTransform()

 Get the current top-most transform entry CanvasTypes.h  

FHitProxyConsumer * GetHitProxyConsumer()

   CanvasTypes.h  

FHitProxyId GetHitProxyId()

   CanvasTypes.h  

FIntPoint GetParentCanvasSize()

   CanvasTypes.h  

FRenderTarget * GetRenderTarget()

 Get the current render target for the canvas CanvasTypes.h  

FSceneInterface * GetScene()

   CanvasTypes.h  

EShaderPlatform GetShaderPlatform()

 Access current shader platform CanvasTypes.h  

FCanvasSortElement & GetSortElement ( int32 DepthSortKey
)

 Get the sort element for the given sort key. Allocates a new entry if one does not exist CanvasTypes.h  

const FGameTime & GetTime()

 Access gameplay time CanvasTypes.h  

FMatrix GetTransform()

 Get the current top-most transform entry without the canvas projection CanvasTypes.h  

const TArray< FTransformEntry > & GetTransformStack()

 Returns the transform stack CanvasTypes.h  

const FIntRect & GetViewRect()

   CanvasTypes.h  

bool HasBatchesToRender()

 Determine if the canvas has dirty batches that need to be rendered CanvasTypes.h  

bool IsHitTesting()

   CanvasTypes.h  

bool IsScaledToRenderTarget()

   CanvasTypes.h  

bool IsStereoRendering()

   CanvasTypes.h  

bool IsUsingInternalTexture()

   CanvasTypes.h  

bool IsWriteDestinationAlphaSet()

   CanvasTypes.h  

int32 PopDepthSortKey()

 Pop sort key off of the stack. CanvasTypes.h  

void PopTransform()

 Removes the top transform from the canvas's transform stack. CanvasTypes.h  

void PushAbsoluteTransform ( const FMatrix& Transform
)

 Pushes a transform onto the canvas's transform stack. CanvasTypes.h  

void PushDepthSortKey ( int32 InSortKey
)

 Push sort key onto the stack. Rendering is done with the current sort key stack entry. CanvasTypes.h  

void PushRelativeTransform ( const FMatrix& Transform
)

 Pushes a transform onto the canvas's transform stack, multiplying it with the current top of the stack. CanvasTypes.h  

void SetAllowedModes ( uint32 InAllowedModes
)

 Toggle allowed canvas modes CanvasTypes.h  

void SetBaseTransform ( const FMatrix& Transform
)

 Replace the base (ie. TransformStack(0)) transform for the canvas with the given matrix CanvasTypes.h  

void SetHitProxy ( HHitProxy* HitProxy
)

 Sets the hit proxy which will be used for subsequent canvas primitives. CanvasTypes.h  

void SetParentCanvasSize ( FIntPoint InParentSize
)

   CanvasTypes.h  

void SetRenderTarget_GameThread ( FRenderTarget* NewRenderTarget
)

 Sets the render target which will be used for subsequent canvas primitives. CanvasTypes.h  

void SetRenderTargetDirty ( bool bDirty
)

 Marks render target as dirty so that it will be resolved to texture CanvasTypes.h  

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 CanvasTypes.h  

void SetRenderTargetScissorRect ( const FIntRect& ScissorRect
)

 The clipping rectangle used when rendering this canvas CanvasTypes.h  

void SetScaledToRenderTarget ( bool bScale
)

   CanvasTypes.h  

void SetStereoRendering ( bool bStereo
)

   CanvasTypes.h  

void SetUseInternalTexture ( const bool bInUseInternalTexture
)

   CanvasTypes.h  

void SetWriteDestinationAlpha ( const bool bInForceWriteAlpha
)

   CanvasTypes.h  

int32 TopDepthSortKey()

 Return top sort key of the stack. CanvasTypes.h  

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

   CanvasTypes.h  

Static

Name Remarks Include Path Unreal Specifiers

static ESimpleElementBlendMode BlendToSimpleElementBlend ( EBlendMode BlendMode
)

 Translate EBlendMode into ESimpleElementBlendMode used by tiles CanvasTypes.h  

static FMatrix CalcBaseTransform2D ( uint32 ViewSizeX,
uint32 ViewSizeY
)

 Generate a 2D projection for the canvas. CanvasTypes.h  

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 CanvasTypes.h  

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

 Generate a projection matrix for the canvas. Used for CalcBaseTransform3D CanvasTypes.h  

static FMatrix CalcViewMatrix ( uint32 ViewSizeX,
uint32 ViewSizeY,
float fFOV
)

 Generate a view matrix for the canvas. Used for CalcBaseTransform3D CanvasTypes.h  

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

   CanvasTypes.h  

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