IInkRenderer::MeasureStroke method

Calculates the rectangle on the device context that would contain a stroke if it were drawn with the InkRenderer object using the DrawStroke method.

Syntax

HRESULT MeasureStroke(
  IInkStrokeDisp        *Stroke,
  IInkDrawingAttributes *DrawingAttributes,
  IInkRectangle         **Rectangle
);

Parameters

Stroke

The stroke to measure.

DrawingAttributes

Optional. The InkDrawingAttributes to use when calculating the rectangle, which override the drawing attributes on the stroke. The default value is NULL, which means the stroke is measured by using its own drawing attributes.

Rectangle

When this method returns, contains a pointer to the rectangle on the device context that would contain the stroke if the stroke were drawn with the DrawStroke method of the InkRenderer object. The stroke must contain x- and y-coordinates to calculate the rectangle. Otherwise, the method returns an empty rectangle.

Return value

This method can return one of these values.

Return code Description
S_OK
Success.
REGDB_E_CLASSNOTREG
The InkRectangle object is not registered on the system.
E_INK_INCOMPATIBLE_OBJECT

IInkStrokeDisp does not point to a compatible InkDisp object, or drawingAttributes is an invalid input parameter.

E_INK_EXCEPTION
An exception occurred inside the method.
E_POINTER
A parameter contained an invalid pointer.
E_INVALIDARG
Invalid display handle.
E_UNEXPECTED
Unexpected parameter or property type.

Remarks

This is accurate only if you pass the same arguments to both MeasureStroke and DrawStroke.

Since the bounding box is affected by the pen width, this width is scaled appropriately for the InkRenderer's view transform. To do this, the pen width is multiplied by the square root of the determinant of the view transform. The height and width of the bounding box are expanded by half this amount in each direction, and the right and bottom sides are incremented by one.

For example, consider that the pen width is originally 53, the square root of the determinant of the view transform is 50, and the bounding box is (0, 0, 1000, 1000). The pen width adjustment to the bounding box in each direction is calculated as (53 * 50) / 2, and the right and bottom sides are incremented by one. This results in a rendered bounding box of (-1325, -1325, 2326, 2326).

Requirements

   
Minimum supported client Windows XP Tablet PC Edition [desktop apps only]
Minimum supported server None supported
Target Platform Windows
Header msinkaut.h
Library InkObj.dll

See also

Draw Method [InkRenderer Class]

DrawStroke Method

IInkRenderer

IInkStrokeDisp Interface

InkRenderer Class

Measure Method