CRenderTarget Class
A wrapper for ID2D1RenderTarget.
class CRenderTarget : public CObject;
| Name | Description |
|---|---|
| CRenderTarget::CRenderTarget | Constructs a CRenderTarget object. |
| CRenderTarget::~CRenderTarget | The destructor. Called when a render target object is being destroyed. |
| Name | Description |
|---|---|
| CRenderTarget::Attach | Attaches existing render target interface to the object |
| CRenderTarget::BeginDraw | Initiates drawing on this render target. |
| CRenderTarget::Clear | Clears the drawing area to the specified color. |
| CRenderTarget::COLORREF_TO_D2DCOLOR | Converts GDI color and alpha values to the D2D1_COLOR_F object. |
| CRenderTarget::CreateCompatibleRenderTarget | Creates a new bitmap render target for use during intermediate offscreen drawing that is compatible with the current render target . |
| CRenderTarget::Destroy | Deletes one or more resources |
| CRenderTarget::Detach | Detaches render target interface from the object |
| CRenderTarget::DrawBitmap | Draws the formatted text described by the specified IDWriteTextLayout object. |
| CRenderTarget::DrawEllipse | Draws the outline of the specified ellipse using the specified stroke style. |
| CRenderTarget::DrawGeometry | Draws the outline of the specified geometry using the specified stroke style. |
| CRenderTarget::DrawGlyphRun | Draws the specified glyphs. |
| CRenderTarget::DrawLine | Draws a line between the specified points using the specified stroke style. |
| CRenderTarget::DrawRectangle | Draws the outline of a rectangle that has the specified dimensions and stroke style. |
| CRenderTarget::DrawRoundedRectangle | Draws the outline of the specified rounded rectangle using the specified stroke style. |
| CRenderTarget::DrawText | Draws the specified text using the format information provided by an IDWriteTextFormat object. |
| CRenderTarget::DrawTextLayout | Draws the formatted text described by the specified IDWriteTextLayout object. |
| CRenderTarget::EndDraw | Ends drawing operations on the render target and indicates the current error state and associated tags. |
| CRenderTarget::FillEllipse | Paints the interior of the specified ellipse. |
| CRenderTarget::FillGeometry | Paints the interior of the specified geometry. |
| CRenderTarget::FillMesh | Paints the interior of the specified mesh. |
| CRenderTarget::FillOpacityMask | Applies the opacity mask described by the specified bitmap to a brush and uses that brush to paint a region of the render target. |
| CRenderTarget::FillRectangle | Paints the interior of the specified rectangle. |
| CRenderTarget::FillRoundedRectangle | Paints the interior of the specified rounded rectangle. |
| CRenderTarget::Flush | Executes all pending drawing commands. |
| CRenderTarget::GetAntialiasMode | Retrieves the current antialiasing mode for nontext drawing operations. |
| CRenderTarget::GetDpi | Returns the render target's dots per inch (DPI) |
| CRenderTarget::GetMaximumBitmapSize | Gets the maximum size, in device-dependent units (pixels), of any one bitmap dimension supported by the render target |
| CRenderTarget::GetPixelFormat | Retrieves the pixel format and alpha mode of the render target |
| CRenderTarget::GetPixelSize | Returns the size of the render target in device pixels |
| CRenderTarget::GetRenderTarget | Returns ID2D1RenderTarget interface |
| CRenderTarget::GetSize | Returns the size of the render target in device-independent pixels |
| CRenderTarget::GetTags | Gets the label for subsequent drawing operations. |
| CRenderTarget::GetTextAntialiasMode | Gets the current antialiasing mode for text and glyph drawing operations. |
| CRenderTarget::GetTextRenderingParams | Retrieves the render target's current text rendering options. |
| CRenderTarget::GetTransform | Applies the specified transform to the render target, replacing the existing transformation. All subsequent drawing operations occur in the transformed space. |
| CRenderTarget::IsSupported | Indicates whether the render target supports the specified properties |
| CRenderTarget::IsValid | Checks resource validity |
| CRenderTarget::PopAxisAlignedClip | Removes the last axis-aligned clip from the render target. After this method is called, the clip is no longer applied to subsequent drawing operations. |
| CRenderTarget::PopLayer | Stops redirecting drawing operations to the layer that is specified by the last PushLayer call. |
| CRenderTarget::PushAxisAlignedClip | Removes the last axis-aligned clip from the render target. After this method is called, the clip is no longer applied to subsequent drawing operations. |
| CRenderTarget::PushLayer | Adds the specified layer to the render target so that it receives all subsequent drawing operations until PopLayer is called. |
| CRenderTarget::RestoreDrawingState | Sets the render target's drawing state to that of the specified ID2D1DrawingStateBlock. |
| CRenderTarget::SaveDrawingState | Saves the current drawing state to the specified ID2D1DrawingStateBlock. |
| CRenderTarget::SetAntialiasMode | Sets the antialiasing mode of the render target. The antialiasing mode applies to all subsequent drawing operations, excluding text and glyph drawing operations. |
| CRenderTarget::SetDpi | Sets the dots per inch (DPI) of the render target. |
| CRenderTarget::SetTags | Specifies a label for subsequent drawing operations. |
| CRenderTarget::SetTextAntialiasMode | Specifies the antialiasing mode to use for subsequent text and glyph drawing operations. |
| CRenderTarget::SetTextRenderingParams | Specifies text rendering options to be applied to all subsequent text and glyph drawing operations. |
| CRenderTarget::SetTransform | Overloaded. Applies the specified transform to the render target, replacing the existing transformation. All subsequent drawing operations occur in the transformed space. |
| Name | Description |
|---|---|
| CRenderTarget::VerifyResource | Verifies CD2DResource object validity; creates the object if it didn't already exist. |
| Name | Description |
|---|---|
| CRenderTarget::operator ID2D1RenderTarget* | Returns ID2D1RenderTarget interface |
| Name | Description |
|---|---|
| CRenderTarget::m_lstResources | A list of pointers to CD2DResource objects. |
| CRenderTarget::m_pRenderTarget | A pointer to an ID2D1RenderTarget object. |
| CRenderTarget::m_pTextFormatDefault | A pointer to CD2DTextFormat object that contains a default text format. |
Header: afxrendertarget.h
The destructor. Called when a render target object is being destroyed.
virtual ~CRenderTarget();
Attaches existing render target interface to the object
void Attach(ID2D1RenderTarget* pRenderTarget);
pRenderTarget
Existing render target interface. Cannot be NULL
Initiates drawing on this render target.
void BeginDraw();
Clears the drawing area to the specified color.
void Clear(D2D1_COLOR_F color);
color
The color to which the drawing area is cleared.
Converts GDI color and alpha values to the D2D1_COLOR_F object.
static D2D1_COLOR_F COLORREF_TO_D2DCOLOR(
COLORREF color,
int nAlpha = 255);
color
RGB value.
nAlpha
D2D1_COLOR_F value.
Creates a new bitmap render target for use during intermediate offscreen drawing that is compatible with the current render target .
BOOL CreateCompatibleRenderTarget(
CBitmapRenderTarget& bitmapTarget,
CD2DSizeF sizeDesired = CD2DSizeF(0., 0.),
CD2DSizeU sizePixelDesired = CD2DSizeU(0, 0),
D2D1_PIXEL_FORMAT* desiredFormat = NULL,
D2D1_COMPATIBLE_RENDER_TARGET_OPTIONS options = D2D1_COMPATIBLE_RENDER_TARGET_OPTIONS_NONE);
bitmapTarget
When this method returns, contains the address of a pointer to a new bitmap render target. This parameter is passed uninitialized.
sizeDesired
The desired size of the new render target in device-independent pixels if it should be different from the original render target, or NULL. For more information, see the Remarks section.
sizePixelDesired
The desired size of the new render target in pixels if it should be different from the original render target, or NULL. For more information, see the Remarks section.
desiredFormat
The desired pixel format and alpha mode of the new render target, or NULL. If the pixel format is set to DXGI_FORMAT_UNKNOWN or if this parameter is null, the new render target uses the same pixel format as the original render target. If the alpha mode is D2D1_ALPHA_MODE_UNKNOWN or this parameter is NULL, the alpha mode of the new render target defaults to D2D1_ALPHA_MODE_PREMULTIPLIED. For information about supported pixel formats, see Supported Pixel Formats and Alpha Modes.
options
A value that specifies whether the new render target must be compatible with GDI.
If the method succeeds, it returns TRUE. Otherwise, it returns FALSE.
Constructs a CRenderTarget object.
CRenderTarget();
Deletes one or more resources
BOOL Destroy(BOOL bDeleteResources = TRUE);
bDeleteResources
If bDeleteResources is TRUE, all resources located in m_lstResources will be automatically destroyed.
If the method succeeds, it returns TRUE. Otherwise, it returns FALSE
Detaches render target interface from the object
ID2D1RenderTarget* Detach ();
Pointer to detached render target interface.
Draws the formatted text described by the specified IDWriteTextLayout object.
void DrawBitmap(
CD2DBitmap* pBitmap,
const CD2DRectF& rectDest,
float fOpacity = 1.0,
D2D1_BITMAP_INTERPOLATION_MODE interpolationMode = D2D1_BITMAP_INTERPOLATION_MODE_LINEAR,
const CD2DRectF* pRectSrc = NULL);
pBitmap
The bitmap to render.
rectDest
The size and position, in device-independent pixels in the render target's coordinate space, of the area to which the bitmap is drawn. If the rectangle is not well-ordered, nothing is drawn, but the render target does not enter an error state.
fOpacity
A value between 0.0f and 1.0f, inclusive, that specifies an opacity value to apply to the bitmap; this value is multiplied against the alpha values of the bitmap's contents.
interpolationMode
The interpolation mode to use if the bitmap is scaled or rotated by the drawing operation.
pRectSrc
The size and position, in device-independent pixels in the bitmap's coordinate space, of the area within the bitmap to draw.
Draws the outline of the specified ellipse using the specified stroke style.
void DrawEllipse(
const CD2DEllipse& ellipse,
CD2DBrush* pBrush,
FLOAT fStrokeWidth = 1.0,
ID2D1StrokeStyle* strokeStyle = NULL);
ellipse
The position and radius of the ellipse to draw, in device-independent pixels.
pBrush
The brush used to paint the ellipse's outline.
fStrokeWidth
The thickness of the ellipse's stroke. The stroke is centered on the ellipse's outline.
strokeStyle
The style of stroke to apply to the ellipse's outline, or NULL to paint a solid stroke.
Draws the outline of the specified geometry using the specified stroke style.
void DrawGeometry(
CD2DGeometry* pGeometry,
CD2DBrush* pBrush,
FLOAT fStrokeWidth = 1.0,
ID2D1StrokeStyle* strokeStyle = NULL);
pGeometry
The geometry to draw.
pBrush
The brush used to paint the geometry's stroke.
fStrokeWidth
The thickness of the geometry's stroke. The stroke is centered on the geometry's outline.
strokeStyle
The style of stroke to apply to the geometry's outline, or NULL to paint a solid stroke.
Draws the specified glyphs.
void DrawGlyphRun(
const CD2DPointF& ptBaseLineOrigin,
const DWRITE_GLYPH_RUN& glyphRun,
CD2DBrush* pForegroundBrush,
DWRITE_MEASURING_MODE measuringMode = DWRITE_MEASURING_MODE_NATURAL);
ptBaseLineOrigin
The origin, in device-independent pixels, of the glyphs' baseline.
glyphRun
The glyphs to render.
pForegroundBrush
The brush used to paint the specified glyphs.
measuringMode
A value that indicates how glyph metrics are used to measure text when it is formatted. The default value is DWRITE_MEASURING_MODE_NATURAL.
Draws a line between the specified points using the specified stroke style.
void DrawLine(
const CD2DPointF& ptFrom,
const CD2DPointF& ptTo,
CD2DBrush* pBrush,
FLOAT fStrokeWidth = 1.0,
ID2D1StrokeStyle* strokeStyle = NULL);
ptFrom
The start point of the line, in device-independent pixels.
ptTo
The end point of the line, in device-independent pixels.
pBrush
The brush used to paint the line's stroke.
fStrokeWidth
A value greater than or equal to 0.0f that specifies the width of the stroke. If this parameter isn't specified, it defaults to 1.0f. The stroke is centered on the line.
strokeStyle
The style of stroke to paint, or NULL to paint a solid line.
Draws the outline of a rectangle that has the specified dimensions and stroke style.
void DrawRectangle(
const CD2DRectF& rectangle,
CD2DBrush* pBrush,
FLOAT fStrokeWidth = 1.0,
ID2D1StrokeStyle* strokeStyle = NULL);
rectangle
The dimensions of the rectangle to draw, in device-independent pixels
pBrush
The brush used to paint the rectangle's stroke
fStrokeWidth
A value greater than or equal to 0.0f that specifies the width of the rectangle's stroke. The stroke is centered on the rectangle's outline.
strokeStyle
The style of stroke to paint, or NULL to paint a solid stroke.
Draws the outline of the specified rounded rectangle using the specified stroke style.
void DrawRoundedRectangle(
const CD2DRoundedRect& rectRounded,
CD2DBrush* pBrush,
FLOAT fStrokeWidth = 1.0,
ID2D1StrokeStyle* strokeStyle = NULL);
rectRounded
The dimensions of the rounded rectangle to draw, in device-independent pixels.
pBrush
The brush used to paint the rounded rectangle's outline.
fStrokeWidth
The width of the rounded rectangle's stroke. The stroke is centered on the rounded rectangle's outline. The default value is 1.0f.
strokeStyle
The style of the rounded rectangle's stroke, or NULL to paint a solid stroke. The default value is NULL.
Draws the specified text using the format information provided by an IDWriteTextFormat object.
void DrawText(
const CString& strText,
const CD2DRectF& rectangle,
CD2DBrush* pForegroundBrush,
CD2DTextFormat* textFormat = NULL,
D2D1_DRAW_TEXT_OPTIONS options = D2D1_DRAW_TEXT_OPTIONS_NONE,
DWRITE_MEASURING_MODE measuringMode = DWRITE_MEASURING_MODE_NATURAL);
strText
A pointer to an array of Unicode characters to draw.
rectangle
The size and position of the area in which the text is drawn.
pForegroundBrush
The brush used to paint the text.
textFormat
An object that describes formatting details of the text to draw, such as the font, the font size, and flow direction.
options
A value that indicates whether the text should be snapped to pixel boundaries and whether the text should be clipped to the layout rectangle. The default value is D2D1_DRAW_TEXT_OPTIONS_NONE, which indicates that text should be snapped to pixel boundaries and it should not be clipped to the layout rectangle.
measuringMode
A value that indicates how glyph metrics are used to measure text when it is formatted. The default value is DWRITE_MEASURING_MODE_NATURAL.
Draws the formatted text described by the specified IDWriteTextLayout object.
void DrawTextLayout(
const CD2DPointF& ptOrigin,
CD2DTextLayout* textLayout,
CD2DBrush* pBrushForeground,
D2D1_DRAW_TEXT_OPTIONS options = D2D1_DRAW_TEXT_OPTIONS_NONE);
ptOrigin
The point, described in device-independent pixels, at which the upper-left corner of the text described by textLayout is drawn.
textLayout
The formatted text to draw. Any drawing effects that do not inherit from ID2D1Resource are ignored. If there are drawing effects that inherit from ID2D1Resource that are not brushes, this method fails and the render target is put in an error state.
pBrushForeground
The brush used to paint any text in textLayout that does not already have a brush associated with it as a drawing effect (specified by the IDWriteTextLayout::SetDrawingEffect method).
options
A value that indicates whether the text should be snapped to pixel boundaries and whether the text should be clipped to the layout rectangle. The default value is D2D1_DRAW_TEXT_OPTIONS_NONE, which indicates that text should be snapped to pixel boundaries and it should not be clipped to the layout rectangle.
Ends drawing operations on the render target and indicates the current error state and associated tags.
HRESULT EndDraw();
If the method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.
Paints the interior of the specified ellipse.
void FillEllipse(
const CD2DEllipse& ellipse,
CD2DBrush* pBrush);
ellipse
The position and radius, in device-independent pixels, of the ellipse to paint.
pBrush
The brush used to paint the interior of the ellipse.
Paints the interior of the specified geometry.
void FillGeometry(
CD2DGeometry* pGeometry,
CD2DBrush* pBrush,
CD2DBrush* pOpacityBrush = NULL);
pGeometry
The geometry to paint.
pBrush
The brush used to paint the geometry's interior.
pOpacityBrush
The opacity mask to apply to the geometry;NULL for no opacity mask. If an opacity mask (the opacityBrush parameter) is specified, brush must be an ID2D1BitmapBrush that has its x- and y-extend modes set to D2D1_EXTEND_MODE_CLAMP. For more information, see the Remarks section.
Paints the interior of the specified mesh.
void FillMesh(
CD2DMesh* pMesh,
CD2DBrush* pBrush);
pMesh
The mesh to paint.
pBrush
The brush used to paint the mesh.
Applies the opacity mask described by the specified bitmap to a brush and uses that brush to paint a region of the render target.
void FillOpacityMask(
CD2DBitmap* pOpacityMask,
CD2DBrush* pBrush,
D2D1_OPACITY_MASK_CONTENT content,
const CD2DRectF& rectDest,
const CD2DRectF& rectSrc);
pOpacityMask
The position and radius, in device-independent pixels, of the ellipse to paint.
pBrush
The brush used to paint the region of the render target specified by destinationRectangle.
content
The type of content the opacity mask contains. The value is used to determine the color space in which the opacity mask is blended.
rectDest
The region of the render target to paint, in device-independent pixels.
rectSrc
The region of the bitmap to use as the opacity mask, in device-independent pixels.
Paints the interior of the specified rectangle.
void FillRectangle(
const CD2DRectF& rectangle,
CD2DBrush* pBrush);
rectangle
The dimension of the rectangle to paint, in device-independent pixels.
pBrush
The brush used to paint the rectangle's interior.
Paints the interior of the specified rounded rectangle.
void FillRoundedRectangle(
const CD2DRoundedRect& rectRounded,
CD2DBrush* pBrush);
rectRounded
The dimensions of the rounded rectangle to paint, in device independent pixels.
pBrush
The brush used to paint the interior of the rounded rectangle.
Executes all pending drawing commands.
void Flush(
D2D1_TAG* tag1 = NULL,
D2D1_TAG* tag2 = NULL);
tag1
Contains the tag for drawing operations that caused errors or 0 if there were no errors. This parameter is passed uninitialized.
tag2
Contains the tag for drawing operations that caused errors or 0 if there were no errors. This parameter is passed uninitialized.
Retrieves the current antialiasing mode for nontext drawing operations.
D2D1_ANTIALIAS_MODE GetAntialiasMode() const;
Current antialiasing mode for nontext drawing operations.
Returns the render target's dots per inch (DPI)
CD2DSizeF GetDpi() const;
The render target's dots per inch (DPI).
Gets the maximum size, in device-dependent units (pixels), of any one bitmap dimension supported by the render target
UINT32 GetMaximumBitmapSize() const;
The maximum size, in pixels, of any one bitmap dimension supported by the render target
Retrieves the pixel format and alpha mode of the render target
D2D1_PIXEL_FORMAT GetPixelFormat() const;
The pixel format and alpha mode of the render target
Returns the size of the render target in device pixels
CD2DSizeU GetPixelSize() const;
The size of the render target in device pixels
Returns ID2D1RenderTarget interface
ID2D1RenderTarget* GetRenderTarget();
Pointer to an ID2D1RenderTarget interface or NULL if object is not initialized yet.
Returns the size of the render target in device-independent pixels
CD2DSizeF GetSize() const;
The current size of the render target in device-independent pixels
Gets the label for subsequent drawing operations.
void GetTags(
D2D1_TAG* tag1 = NULL,
D2D1_TAG* tag2 = NULL) const;
tag1
Contains the first label for subsequent drawing operations. This parameter is passed uninitialized. If NULL is specified, no value is retrieved for this parameter.
tag2
Contains the second label for subsequent drawing operations. This parameter is passed uninitialized. If NULL is specified, no value is retrieved for this parameter.
Gets the current antialiasing mode for text and glyph drawing operations.
D2D1_TEXT_ANTIALIAS_MODE GetTextAntialiasMode() const;
Current antialiasing mode for text and glyph drawing operations.
Retrieves the render target's current text rendering options.
void GetTextRenderingParams(IDWriteRenderingParams** textRenderingParams);
textRenderingParams
When this method returns, textRenderingParamscontains the address of a pointer to the render target's current text rendering options.
Gets the current transform of the render target.
void GetTransform(D2D1_MATRIX_3X2_F* transform);
transform
When this returns, contains the current transform of the render target. This parameter is passed uninitialized.
Indicates whether the render target supports the specified properties
BOOL IsSupported(const D2D1_RENDER_TARGET_PROPERTIES& renderTargetProperties) const;
renderTargetProperties
The render target properties to test
TRUE if the specified render target properties are supported by this render target; otherwise, FALSE
Checks resource validity
BOOL IsValid() const;
TRUE if resource is valid; otherwise FALSE.
A list of pointers to CD2DResource objects.
CObList m_lstResources;
A pointer to an ID2D1RenderTarget object.
ID2D1RenderTarget* m_pRenderTarget;
A pointer to CD2DTextFormat object that contains a default text format.
CD2DTextFormat* m_pTextFormatDefault;
Returns ID2D1RenderTarget interface
operator ID2D1RenderTarget*();
Pointer to an ID2D1RenderTarget interface or NULL if object is not initialized yet.
Removes the last axis-aligned clip from the render target. After this method is called, the clip is no longer applied to subsequent drawing operations.
void PopAxisAlignedClip();
Stops redirecting drawing operations to the layer that is specified by the last PushLayer call.
void PopLayer();
Removes the last axis-aligned clip from the render target. After this method is called, the clip is no longer applied to subsequent drawing operations.
void PushAxisAlignedClip(
const CD2DRectF& rectClip,
D2D1_ANTIALIAS_MODE mode = D2D1_ANTIALIAS_MODE_PER_PRIMITIVE);
rectClip
The size and position of the clipping area, in device-independent pixels.
mode
The antialiasing mode that is used to draw the edges of clip rectangles that have subpixel boundaries, and to blend the clip with the scene contents. The blending is performed once when the PopAxisAlignedClip method is called, and does not apply to each primitive within the layer.
Adds the specified layer to the render target so that it receives all subsequent drawing operations until PopLayer is called.
void PushLayer(
const D2D1_LAYER_PARAMETERS& layerParameters,
CD2DLayer& layer);
layerParameters
The content bounds, geometric mask, opacity, opacity mask, and antialiasing options for the layer.
layer
The layer that receives subsequent drawing operations.
Sets the render target's drawing state to that of the specified ID2D1DrawingStateBlock.
void RestoreDrawingState(ID2D1DrawingStateBlock& drawingStateBlock);
drawingStateBlock
The new drawing state of the render target.
Saves the current drawing state to the specified ID2D1DrawingStateBlock.
void SaveDrawingState(ID2D1DrawingStateBlock& drawingStateBlock) const;
drawingStateBlock
When this method returns, contains the current drawing state of the render target. This parameter must be initialized before passing it to the method.
Sets the antialiasing mode of the render target. The antialiasing mode applies to all subsequent drawing operations, excluding text and glyph drawing operations.
void SetAntialiasMode(D2D1_ANTIALIAS_MODE antialiasMode);
antialiasMode
The antialiasing mode for future drawing operations.
Sets the dots per inch (DPI) of the render target.
void SetDpi(const CD2DSizeF& sizeDPI);
sizeDPI
A value greater than or equal to zero that specifies the horizontal/verticalDPI of the render target.
Specifies a label for subsequent drawing operations.
void SetTags(
D2D1_TAG tag1,
D2D1_TAG tag2);
tag1
A label to apply to subsequent drawing operations.
tag2
A label to apply to subsequent drawing operations.
Specifies the antialiasing mode to use for subsequent text and glyph drawing operations.
void SetTextAntialiasMode(D2D1_TEXT_ANTIALIAS_MODE textAntialiasMode);
textAntialiasMode
The antialiasing mode to use for subsequent text and glyph drawing operations.
Specifies text rendering options to be applied to all subsequent text and glyph drawing operations.
void SetTextRenderingParams(IDWriteRenderingParams* textRenderingParams = NULL);
textRenderingParams
The text rendering options to be applied to all subsequent text and glyph drawing operations; NULL to clear current text rendering options.
Applies the specified transform to the render target, replacing the existing transformation. All subsequent drawing operations occur in the transformed space.
void SetTransform(const D2D1_MATRIX_3X2_F* transform);
void SetTransform(const D2D1_MATRIX_3X2_F& transform);
transform
The transform to apply to the render target.
Verifies CD2DResource object validity; creates the object if it didn't already exist.
BOOL VerifyResource(CD2DResource* pResource);
pResource
Pointer to CD2DResource object.
TRUE is object if valid; otherwise FALSE.