IInkRenderer::Measure method

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

Syntax

HRESULT Measure(
  IInkStrokes   *Strokes,
  IInkRectangle **Rectangle
);

Parameters

Strokes

The collection of strokes to measure.

Rectangle

When this method returns, contains a pointer to the rectangle on the device context that would contain the strokes if they were drawn with the DrawStroke method of the InkRenderer object. The strokes 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.
E_POINTER
A parameter contained an invalid pointer.
E_INVALIDARG
Invalid display handle.
E_INK_INCOMPATIBLE_OBJECT
The strokes parameter does not point to a valid object.
E_INK_MISMATCHED_INK_OBJECT
The strokes parameter is associated with a different InkDisp object.
E_INK_EXCEPTION
An exception occurred inside the method.
E_UNEXPECTED
Unexpected parameter or property type.

Remarks

This is accurate only if you pass the same arguments to both Measure 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]

IInkRenderer

IInkStrokeDisp Interface

InkRenderer Class

MeasureStroke Method