RSurface Class Reference

Abstraction for rendering into an RImage. More...

#include <RSurface.h>

Inheritance diagram for RSurface:

Public Member Functions
std::shared_ptr< RPass >	beginPass (CZBitset< RPassCap > caps=RPassCap_Painter|RPassCap_SkCanvas, RDevice *device=nullptr) const noexcept
	Begins a rendering pass.
std::shared_ptr< RImage >	image () const noexcept
	Returns the backing image used by the surface.
bool	setGeometry (const RSurfaceGeometry &geometry) noexcept
	Updates the viewport -> (transform) -> dst mapping.
const RSurfaceGeometry &	geometry () const noexcept
	Returns the current viewport -> (transform) -> dst mapping.
bool	resize (SkISize size, SkScalar scale, bool shrink=false) noexcept
	Resizes the surface and optionally shrinks the backing image to fit the new destination size.
	~RSurface () noexcept
	Destructor.
Public Member Functions inherited from RObject
	RObject ()=default
	Constructs a default RObject.

Static Public Member Functions
static std::shared_ptr< RSurface >	Make (SkISize size, SkScalar scale, bool alpha) noexcept
	Creates a new surface with an internal image.
static std::shared_ptr< RSurface >	WrapImage (std::shared_ptr< RImage > image) noexcept
	Creates a surface from an existing RImage.

Detailed Description

Abstraction for rendering into an RImage.

RSurface wraps an RImage and provides convenience APIs to render using either RPainter or Skia SkCanvas. It maintains a virtual viewport and pixel destination rectangle to control coordinate mapping.

Constructor & Destructor Documentation

~RSurface()

~RSurface ( )

noexcept

Destructor.

Member Function Documentation

Make()

static std::shared_ptr< RSurface > Make ( SkISize  size, SkScalar  scale, bool  alpha  )

staticnoexcept

Creates a new surface with an internal image.

The created image will have at least the following caps for the main device:

• RImageCap_Src
• RImageCap_Dst
• RImageCap_SkImage
• RImageCap_SkSurface

Parameters

size	Viewport size (unscaled).
scale	Scale factor.
alpha	Whether the RImage format has alpha.

Returns

A shared pointer to the new RSurface, or nullptr on failure.

Note

If additional caps are needed, create an RImage manually and use WrapImage().

WrapImage()

static std::shared_ptr< RSurface > WrapImage ( std::shared_ptr< RImage >  image )

staticnoexcept

Creates a surface from an existing RImage.

Wraps an existing image without copying it.

Note

The alphaType() of the backing storage/destination image is ignored and always considered premultiplied alpha.

Parameters

image

An existing image with suitable caps.

Returns

A new surface wrapping the image, or nullptr on failure.

beginPass()

std::shared_ptr< RPass > beginPass ( CZBitset< RPassCap >  caps = RPassCap_Painter|RPassCap_SkCanvas, RDevice *  device = nullptr  ) const

noexcept

Begins a rendering pass.

Parameters

device

Optional device to use. If nullptr, the main device is used.

Returns

A valid RPass object on success, or an invalid RPass on failure.

image()

std::shared_ptr< RImage > image ( ) const

inlinenoexcept

Returns the backing image used by the surface.

Returns

Shared pointer to the underlying RImage. Always valid.

setGeometry()

bool setGeometry ( const RSurfaceGeometry &  geometry )

noexcept

Updates the viewport -> (transform) -> dst mapping.

Unlike resize(), it never allocates a new image, even if the destination exceeds image bounds.

Parameters

viewport	Portion of the world to capture.
dst	Pixel area within the image to render into.
transform	Optional transform to apply (defaults to CZTransform::Normal).

Returns

true if geometry was successfully set, false if invalid.

geometry()

const RSurfaceGeometry & geometry ( ) const

inlinenoexcept

Returns the current viewport -> (transform) -> dst mapping.

resize()

bool resize ( SkISize  size, SkScalar  scale, bool  shrink = false  )

noexcept

Resizes the surface and optionally shrinks the backing image to fit the new destination size.

Parameters

size	Unscaled image size (viewport size).
scale	Scale factor.
shrink	If true, a new image will be allocated if the new dst size is different than the current image. If false, the existing image is reused as long as it is large enough.

Returns

true if a new image was allocated, false if the current image was reused.