Canvas (ImageKit Control/ Effect Method)

The Canvas method produces a canvas effect on the raster image.

[C++Builder] [ bool = ]imagekitcontrolname->Effect->Canvas(const TPoint * Points, const int Points_Size, short Direction, short Depth)

[C++Builder] [ bool = ]imagekitcontrolname->Effect->Canvas(short Direction, short Depth)

[Delphi] [ Boolean = ]imagekitcontrolname.Effect.Canvas(const Points: array of TPoint; Direction: Smallint; Depth: Smallint)

[Delphi] [ Boolean = ]imagekitcontrolname.Effect.Canvas(Direction: Smallint; Depth: Smallint)

Parameters

Name	Explanation
Points	An array of x and y coordinate values defining points of a polygonal area on the image. (in pixels) In C++Builder, the size of the Points array is given by Points_Size - 1
Direction	The direction of the canvas pattern (0:From top to right, 1: From top to left, 2: From bottom to left, 3: From bottom to right)
Depth	Depth of the canvas pattern. (From 0 to 255). As the Depth value increases the canvas effect becomes stronger

Return Value

Returns True if successful, otherwise returns False.

Explanation

The Canvas method produces a canvas effect on the raster image. To execute the Canvas method, set the image handle of the image in the ImageHandle property or the Layer(LayerNo).ImageHandle property. The Canvas method supports 8-bit grayscale, 16, 24, and 32 bit images.

Before executing the Canvas method, you must set the area on the image that will be affected. There are 4 ways to do this.

To use a mask image, set the SelectMode property to vikEffectMask. Set the mask image handle in the MaskImageHandle property
To process the total image, set the SelectMode property to vikEffectAll.
To process the polygonal area on the image, set the SelectMode property to vikEffectPolygon. Select the polygon by setting the appropriate coordinate values for the points of the polygon in the Points array. The number of points defining the polygon must be 3 or more.
To process an elliptical area on the image, set the SelectMode property to vikEffectEllipse. Select the ellipse by setting the appropriate values for the bounding rectangle in the RectLeft, RectTop, RectRight, and RectBottom properties

When the SelectMode property is set to vikEffectPolygon or vikEffectEllipse, the InOut property should be set. When the SelectMode property is set to values other than vikEffectPolygon, please set the Points parameter to a dummy array or to NULL.

If successful, the resulting raster image data is set in the LayerNo property (the ImageHandle property or the Layer(LayerNo).ImageHandle property. If unsuccessful, 0 is returned.

When the Caption, Message, and ButtonName properties are blank, the progress dialog box will not be displayed. When the progress dialog box is displayed, the percentage that the processing has completed will be shown in the dialog box.

Differences from the ImageKit 7/8/9/10 ActiveX

The parameters x, y have been changed to type TPoint
In Delphi, it is not necessary to pass the size of the array of x, y points.