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Transformer Class

Summary
Helper class used for converting physical to logical coordinates and vice versa based on a given matrix.
Syntax
C#
C++/CLI
Python
public class Transformer 
public ref class Transformer  
class Transformer: 
Requirements

Target Platforms

Example

The example shows how to use the Transformer members to convert physical to logical coordinates and vice versa. The converted coordinates are then used to zoom in the image while at the center point.

Before After
Before using Transformer to zoom in
After using Transformer to zoom in
C#
using Leadtools.Codecs; 
using Leadtools.Drawing; 
 
using Leadtools.WinForms; 
 
 
public void CenterAtPoint(RasterImageViewer viewer) 
{ 
   // Minimum and maximum scale factors allowed (change if you have to) 
   const double minimumScaleFactor = 0.05; 
   const double maximumScaleFactor = 11;          
 
   // Normalize the scale factor based on min and max 
   scaleFactor = Math.Max(minimumScaleFactor, Math.Min(maximumScaleFactor, scaleFactor)); 
 
   // Check if we need to change the scale factor for the viewer 
   if (viewer.ScaleFactor != scaleFactor) 
   { 
      viewer.BeginUpdate(); 
 
      // Get the current center in logical units 
      // We will use this point later to re-center the viewer 
 
      // Get what you see in physical coordinates 
      Rectangle rc = Rectangle.Intersect(viewer.PhysicalViewRectangle, viewer.ClientRectangle); 
 
      // Get the center of what you see in physical coordinates 
      PointF center = new PointF(rc.Left + rc.Width / 2, rc.Top + rc.Height / 2); 
 
      Transformer t = new Transformer(viewer.Transform); 
      // Get the center of what you see in logical coordinates 
      center = t.PointToLogical(center); 
 
      // Set the new scale factor 
      viewer.ScaleFactor = scaleFactor; 
 
      // Bring the original center into the view center 
 
      t = new Transformer(viewer.Transform); 
      // Get the center of what you saw before the zoom in physical coordinates 
      center = t.PointToPhysical(center); 
 
      // Bring the old center into the center of the view 
      viewer.CenterAtPoint(Point.Round(center)); 
      viewer.EndUpdate(); 
 
      //Code below is informational and only provides values for Transformer members 
      // and does not impact the image in this demo: 
 
      // Get the logical coordinates of the Rectangle 
      RectangleF recLogical = t.RectangleToLogical(rc); 
 
      // Get the physical coordinates of the Rectangle 
      RectangleF recPhysical = t.RectangleToPhysical(rc); 
 
      // Get the logical length 
      float xlengthLogical = t.LengthToLogical(center.X); 
 
      // Get the logical length 
      float xlengthPhysical = t.LengthToPhysical(center.X); 
 
      Console.WriteLine($"recLogical: {recLogical}\nrecPhysical{recPhysical}\nxlengthLogical :{xlengthLogical}\nxlengthPhysical:{xlengthPhysical}"); 
 
      // Convert input logical points to physical points 
      // Define logical points 
      PointF[] points = new PointF[2]; 
      points[0].X = 10.00F; 
      points[0].Y = 10.00F; 
      points[0].X = 20.00F; 
      points[0].Y = 20.00F; 
      // Convert to physical points 
      PointF[] physicalPoints = Transformer.TransformPoints(points, viewer.Transform); 
      for (int i = 0; i < physicalPoints.Length; i++) 
      { 
         Console.WriteLine($"Logical Points: {physicalPoints[i].X}, {physicalPoints[i].Y}"); 
         Console.WriteLine($"Physical Points:{physicalPoints[i].X}, {physicalPoints[i].Y}"); 
      } 
   } 
} 
Help Version 23.0.2024.2.29
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Leadtools.Drawing Assembly
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.