Leadtools Send comments on this topic. | Back to Introduction - All Topics | Help Version 15.3.5
RasterRegionXForm Class
See Also  Members  
Leadtools Namespace : RasterRegionXForm Class




Provides data for translating between region coordinates and external representations of those coordinates.

Syntax

Visual Basic (Declaration) 
Public Class RasterRegionXForm
Visual Basic (Usage)Copy Code
Dim instance As RasterRegionXForm
C# 
public class RasterRegionXForm
Managed Extensions for C++ 
public __gc class RasterRegionXForm
C++/CLI 
public ref class RasterRegionXForm

Example

For an example, refer to RegionToGdiPlusRegion.

Remarks

All region methods accept a null reference (Nothing in Visual Basic). In that case, no transformation occurs. The scalar fields default to 1, the offsets default to 0, and the view perspective defaults to the image view perspective.

Several of the LEADTOOLS methods for creating and working with an image region use coordinates from an external representation of the region, such as a shape drawn in a device context. To compensate for possible differences in view perspective, scaling, and display offsets, these LEADTOOLS methods require that you provide translation information in an RasterRegionXForm object.

In most cases, the external representation of an image region is scaled and positioned relative to the display coordinates of a LEADTOOLS painting method. Therefore, the following table describes the fields to set in the RasterRegionXForm object, based on the parameters of the display methods.

When assigning an external representation to an image, every point (Xa, Ya) in the an external representation is transformed (by RasterRegionXForm) to point (Xc, Yc) in the image region as follows:


1. Add offsets:
     Xb = Xa + XForm.XOffset
     Yb = Ya + XForm.YOffset

2. Multiply by scalars:
     Xc = (Xb * XForm.XScalarNumerator) / XForm.XScalarDenominator
     Yc = (Yb * XForm.YScalarNumerator) / XForm.YScalarDenominator

3. Compensate for view perspective (updating Xc and Yc in place):
     PointToImage(XForm.ViewPerspective, Xc, Yc)

When retrieving an external representation from an image, every point (Xa, Ya) in the image region is transformed (by RasterRegionXForm) to point (Xc, Yc) in the external region as follows:


1. Compensate for view perspective (updating Xa and Ya in place):
     PointFromImage(XForm.ViewPerspective, Xa, Ya)

2. Mulitply by scalars:
     Xb = (Xa * XForm.XScalarNumerator) / XForm.XScalarDenominator
     Yb = (Ya * XForm.YScalarNumerator) / XForm.YScalarDenominator

3. Add offsets:
     Xc = Xb + XForm.XOffset
     Yc = Yb + XForm.YOffset

For more information, refer to Translating Coordinates for a Region..

Inheritance Hierarchy

System.Object
   Leadtools.RasterRegionXForm

Requirements

Target Platforms: Microsoft .NET Framework 2.0, Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also