Direct2D API Reference
This section provides detailed information on the Direct2D interfaces, functions, structures, and enumerations used for hardware-accelerated 2D graphics rendering on Windows.
Interfaces
Direct2D uses COM interfaces to expose its functionality. Key interfaces include:
HRESULT D2D1CreateFactory( D2D1_FACTORY_TYPE factoryType, REFIID riid, CONST D2D1_FACTORY_OPTIONS *pFactoryOptions, void **ppvFactory );
D2D1CreateFactory
Creates an instance of the Direct2D factory. The factory is used to create other Direct2D objects, such as render targets, geometries, and brushes.
Parameters
factoryType: A D2D1_FACTORY_TYPE value that specifies the threading model of the factory.riid: A reference to the GUID of the desired factory interface.pFactoryOptions: A pointer to a D2D1_FACTORY_OPTIONS structure that contains optional features for the factory. Can be NULL.ppvFactory: A pointer to a variable that receives a pointer to the new Direct2D factory.
Return Value
- An HRESULT indicating whether the factory was created successfully.
void DrawLine( D2D1_POINT_2F point1, D2D1_POINT_2F point2, CONST D2D1_COLOR_F &color, FLOAT strokeWidth, CONST ID2D1StrokeStyle *strokeStyle );
ID2D1DeviceContext::DrawLine
Draws a line using the specified color and stroke style.
Parameters
point1: The starting point of the line.point2: The ending point of the line.color: The color of the line.strokeWidth: The width of the line.strokeStyle: An optional pointer to a stroke style object that defines the appearance of the line's stroke.
HRESULT CreateBitmap( D2D1_SIZE_U size, CONST void *pSourceData, UINT32 pitch, CONST D2D1_BITMAP_PROPERTIES &bitmapProperties, ID2D1Bitmap **ppBitmap );
ID2D1DeviceContext::CreateBitmap
Creates a Direct2D bitmap from source data.
Parameters
size: The dimensions of the bitmap.pSourceData: Pointer to the bitmap data.pitch: The byte pitch of the bitmap data.bitmapProperties: Properties of the bitmap, including pixel format and DPI.ppBitmap: Pointer to the created bitmap object.
Return Value
- An HRESULT indicating success or failure.
void SetColor( CONST D2D1_COLOR_F &color );
ID2D1SolidColorBrush::SetColor
Sets the color of the solid color brush.
Parameters
color: The new color for the brush.
Functions
HRESULT D2D1CreateFactory( D2D1_FACTORY_TYPE factoryType, REFIID riid, CONST D2D1_FACTORY_OPTIONS *pFactoryOptions, void **ppvFactory );
D2D1CreateFactory
Creates an instance of the Direct2D factory. This is the entry point for using Direct2D.
Parameters
factoryType: A D2D1_FACTORY_TYPE value that specifies the threading model of the factory.riid: A reference to the GUID of the desired factory interface (e.g., IID_ID2D1Factory).pFactoryOptions: A pointer to a D2D1_FACTORY_OPTIONS structure that contains optional features for the factory. Can be NULL.ppvFactory: A pointer to a variable that receives a pointer to the new Direct2D factory.
Return Value
- An HRESULT indicating whether the factory was created successfully.
Structures
Commonly used structures include:
- D2D1_POINT_2F: Represents a 2D point with float coordinates.
- D2D1_COLOR_F: Represents an RGBA color with float components.
- D2D1_RECT_F: Represents a rectangle with float coordinates.
- D2D1_MATRIX_4X4_F: Represents a 4x4 transformation matrix.
Enumerations
Key enumerations for configuring Direct2D objects:
- D2D1_DRAW_TEXT_OPTIONS: Options for drawing text.
- D2D1_RENDER_TARGET_USAGE: Usage flags for render targets.
- D2D1_ANTIALIAS_MODE: Antialiasing modes.