TLazCanvas

type TLazCanvas = class(TFPImageCanvas)

protected

  procedure SetColor(); override;

Sets the color for the pixel at the specified coordinates.

  function DoCreateDefaultFont; override;

Creates the custom font used as the default for the canvas.

  procedure DoRectangle(); override;

Adjusts the fcl-image coordinate system to be compatible with coordinates used in TCanvas.

  procedure DoRectangleFill(); override;

Adjusts the FCL image rectangle to be LCL compatible and draws a filled rectangle on the canvas.

  procedure DoPolygonFill(); override;

Implements a polygon fill algorithm not present in fcl-image prior to FPC version 3.2.3.

  procedure DoLine(); override;

Draws a line using the specified coordinates and Pen for the canvas.

  procedure DoCopyRect(); override;

Performs actions needed to copy a source rectangle from the specified canvas.

  procedure DoDraw(); override;

Performs actions needed to draws the specified image at the given coordinates using AlphaBlending.

public

  HasNoImage: Boolean;

Indicates if a valid image was provided in the constructor.

  NativeDC: PtrInt;

Native device context for the canvas.

  ExtraFontData: TObject;

Member with extra FreeType font data from the canvas or device context.

  ImageFormat: TLazCanvasImageFormat;

Member with the TLazCanvasImageFormat instance used to speed up drawing.

  SelectedBitmap: TObject;

Member with the GDI Handle for an image.

  constructor create();

Constructor for the class instance.

  destructor destroy; override;

Destructor for the class instance.

  procedure SetLazClipRegion();

Sets the value in the ClipRegion property.

  function SaveState;

Saves the current canvas state in the GraphicStateList member.

  procedure RestoreState();

Restores the canvas to the state stored at the specified position.

  procedure ResetCanvasState;

Sets the canvas to the default values/state used in the LCL TCanvas class.

  procedure AlphaBlend();

Alpha blends the specified content from the source canvas onto the canvas instance.

  procedure AlphaBlendIgnoringDestPixels();

Performs an AlphaBlend operation assuming a white background.

  procedure AlphaBlend_Image();

AlphaBlends the specified image onto the canvas.

  procedure DoDrawImage();

Calls DoDraw for the specified image and coordinates.

  procedure CanvasCopyRect();

Copies the contents of a supported image format in ASource to the canvas.

  procedure FillColor();

Fills the entire drawing area with the specified color.

  procedure Polygon(); overload;

Overloaded method which adds support for the non-zero winding rule.

  procedure AssignPenData();

Sets the Pen data for the canvas.

  procedure AssignBrushData();

Sets the Brush data for the canvas.

  procedure AssignFontData();

Sets the Font data for the canvas.

  property AssignedPen: TFPCustomPen; [rw]

Pen assigned to the canvas.

  property AssignedBrush: TFPCustomBrush; [rw]

Brush assigned to the canvas.

  property AssignedFont: TFPCustomFont; [rw]

Font assigned to the canvas.

  property BaseWindowOrg: TPoint; [rw]

Base window origin for the canvas.

  property WindowOrg: TPoint; [rw]

Window origin for the canvas.

end;

TLazCanvas

Implements a canvas which masks differences between FCL and LCL canvas classes.

TFPImageCanvas

TObject

TCanvas

Implements a drawing surface for a visual control or bitmap image.