Zoom Extents in .Net

CSharpBoy

Zoom Extents in .Net

Issue
Do you have any .Net sample code that illustrates how to perform a zoom extents in model space and ** space from .Net?

Solution
The two following C# samples illustrate how to do zoom extents for both model and ** space using pure .Net AutoCAD API:

1. public void SetViewportToExtents(Database db, ViewportTableRecord viewportTableRec)
   
2. {
   
3.     //lets update the database extents first
   
4.     //true gives the best fit but will take time
   
5.     db.UpdateExt(true);
   
6. 
   
7.     //get the screen aspect ratio to calculate the height and width
   
8.     double scrRatio = (viewportTableRec.Width / viewportTableRec.Height);
   
9. 
   
10.     //prepare Matrix for DCS to WCS transformation
    
11.     Matrix3d matWCS2DCS = Matrix3d.PlaneToWorld(viewportTableRec.ViewDirection);
    
12. 
    
13.     //for DCS target point is the origin
    
14.     matWCS2DCS = Matrix3d.Displacement(viewportTableRec.Target-Point3d.Origin) * matWCS2DCS;
    
15. 
    
16.     //WCS Xaxis is twisted by twist angle
    
17.     matWCS2DCS = Matrix3d.Rotation(-viewportTableRec.ViewTwist,
    
18.                                     viewportTableRec.ViewDirection,
    
19.                                     viewportTableRec.Target)
    
20.                                     * matWCS2DCS;
    
21. 
    
22.     matWCS2DCS = matWCS2DCS.Inverse();
    
23. 
    
24.     //tranform the extents to the DCS defined by the viewdir
    
25.     Extents3d extents = new Extents3d(db.Extmin, db.Extmax);
    
26.     extents.TransformBy(matWCS2DCS);
    
27. 
    
28.     //width of the extents in current view
    
29.     double width = (extents.MaxPoint.X - extents.MinPoint.X);
    
30. 
    
31.     //height of the extents in current view
    
32.     double height = (extents.MaxPoint.Y - extents.MinPoint.Y);
    
33. 
    
34.     //get the view center point
    
35.     Point2d center = new Point2d((extents.MaxPoint.X  + extents.MinPoint.X)*0.5,
    
36.                                  (extents.MaxPoint.Y  + extents.MinPoint.Y)*0.5);
    
37. 
    
38.     //check if the width 'fits' in current window
    
39.     //if not then get the new height as per the viewports aspect ratio
    
40.     if (width > (height * scrRatio))
    
41.         height = width / scrRatio;
    
42. 
    
43.     viewportTableRec.Height = height;
    
44.     viewportTableRec.Width = height * scrRatio;
    
45.     viewportTableRec.CenterPoint = center;
    
46. }
    
47. 
    
48. [CommandMethod("ModelZoomExtents")]
    
49. public void ModelZoomExtents()
    
50. {
    
51.     Document doc = Application.DocumentManager.MdiActiveDocument;
    
52.     Database db = doc.Database;
    
53.     Editor ed = doc.Editor;
    
54. 
    
55.     using (Transaction Tx = db.TransactionManager.StartTransaction())
    
56.     {
    
57.         ed.UpdateTiledViewportsInDatabase();
    
58. 
    
59.         ViewportTableRecord viewportTableRec = Tx.GetObject(ed.ActiveViewportId, OpenMode.ForWrite) as ViewportTableRecord;
    
60. 
    
61.         SetViewportToExtents(db, viewportTableRec);
    
62. 
    
63.         ed.UpdateTiledViewportsFromDatabase();
    
64. 
    
65.         Tx.Commit();
    
66.     }
    
67. }
    
68. 
    
69. [CommandMethod("**ZoomExtents")]
    
70. static public void **ZoomExtents()
    
71. {
    
72.     Document doc = Application.DocumentManager.MdiActiveDocument;
    
73.     Database db = doc.Database;
    
74.     Editor ed = doc.Editor;
    
75. 
    
76.     PromptEntityOptions peo = new PromptEntityOptions("\nSelect a viewport: ");
    
77.     peo.SetRejectMessage("\nMust be a viewport...");
    
78.     peo.AddAllowedClass(typeof(Viewport), true);
    
79. 
    
80.     PromptEntityResult per = ed.GetEntity(peo);
    
81. 
    
82.     if (per.Status != PromptStatus.OK) return;
    
83. 
    
84.     using (Transaction Tx = db.TransactionManager.StartTransaction())
    
85.     {
    
86.         Viewport vp = Tx.GetObject(per.ObjectId, OpenMode.ForWrite) as Viewport;
    
87. 
    
88. 
    
89.         db.UpdateExt(true);
    
90. 
    
91.         double scrRatio = (vp.Width / vp.Height);
    
92. 
    
93.         Matrix3d matWCS2DCS = Matrix3d.PlaneToWorld(vp.ViewDirection);
    
94. 
    
95.         matWCS2DCS = Matrix3d.Displacement(vp.ViewTarget-Point3d.Origin) * matWCS2DCS;
    
96. 
    
97.         matWCS2DCS = Matrix3d.Rotation(-vp.TwistAngle,
    
98.                                         vp.ViewDirection,
    
99.                                         vp.ViewTarget)
    
100.                                         * matWCS2DCS;
     
101. 
     
102.         matWCS2DCS = matWCS2DCS.Inverse();
     
103. 
     
104.         Extents3d extents = new Extents3d(db.Extmin, db.Extmax);
     
105.         extents.TransformBy(matWCS2DCS);
     
106. 
     
107.         double width = (extents.MaxPoint.X - extents.MinPoint.X);
     
108. 
     
109.         double height = (extents.MaxPoint.Y - extents.MinPoint.Y);
     
110. 
     
111.         Point2d center = new Point2d((extents.MaxPoint.X  + extents.MinPoint.X)*0.5,
     
112.                                      (extents.MaxPoint.Y  + extents.MinPoint.Y)*0.5);
     
113. 
     
114.         if (width > (height * scrRatio))
     
115.             height = width / scrRatio;
     
116. 
     
117.         vp.ViewHeight = height;
     
118.         vp.ViewCenter = center;
     
119. 
     
120.         Tx.Commit();
     
121.     }
     
122. }
     

public void SetViewportToExtents(Database db, ViewportTableRecord viewportTableRec)<br /> {<br />     //lets update the database extents first<br />     //true gives the best fit but will take time<br />     db.UpdateExt(true);<br /> <br />     //get the screen aspect ratio to calculate the height and width<br />     double scrRatio = (viewportTableRec.Width / viewportTableRec.Height);<br /> <br />     //prepare Matrix for DCS to WCS transformation<br />     Matrix3d matWCS2DCS = Matrix3d.PlaneToWorld(viewportTableRec.ViewDirection);<br /> <br />     //for DCS target point is the origin<br />     matWCS2DCS = Matrix3d.Displacement(viewportTableRec.Target-Point3d.Origin) * matWCS2DCS;<br /> <br />     //WCS Xaxis is twisted by twist angle<br />     matWCS2DCS = Matrix3d.Rotation(-viewportTableRec.ViewTwist,<br />                                     viewportTableRec.ViewDirection,<br />                                     viewportTableRec.Target)<br />                                     * matWCS2DCS;<br /> <br />     matWCS2DCS = matWCS2DCS.Inverse();<br /> <br />     //tranform the extents to the DCS defined by the viewdir<br />     Extents3d extents = new Extents3d(db.Extmin, db.Extmax);<br />     extents.TransformBy(matWCS2DCS);<br /> <br />     //width of the extents in current view<br />     double width = (extents.MaxPoint.X - extents.MinPoint.X);<br /> <br />     //height of the extents in current view<br />     double height = (extents.MaxPoint.Y - extents.MinPoint.Y);<br /> <br />     //get the view center point<br />     Point2d center = new Point2d((extents.MaxPoint.X  + extents.MinPoint.X)*0.5,<br />                                  (extents.MaxPoint.Y  + extents.MinPoint.Y)*0.5);<br /> <br />     //check if the width 'fits' in current window<br />     //if not then get the new height as per the viewports aspect ratio<br />     if (width > (height * scrRatio))<br />         height = width / scrRatio;<br /> <br />     viewportTableRec.Height = height;<br />     viewportTableRec.Width = height * scrRatio;<br />     viewportTableRec.CenterPoint = center;<br /> }<br /> <br /> [CommandMethod("ModelZoomExtents")]<br /> public void ModelZoomExtents()<br /> {<br />     Document doc = Application.DocumentManager.MdiActiveDocument;<br />     Database db = doc.Database;<br />     Editor ed = doc.Editor;<br /> <br />     using (Transaction Tx = db.TransactionManager.StartTransaction())<br />     {<br />         ed.UpdateTiledViewportsInDatabase();<br /> <br />         ViewportTableRecord viewportTableRec = Tx.GetObject(ed.ActiveViewportId, OpenMode.ForWrite) as ViewportTableRecord;<br /> <br />         SetViewportToExtents(db, viewportTableRec);<br /> <br />         ed.UpdateTiledViewportsFromDatabase();<br /> <br />         Tx.Commit();<br />     }<br /> }<br /> <br /> [CommandMethod("**ZoomExtents")]<br /> static public void **ZoomExtents()<br /> {<br />     Document doc = Application.DocumentManager.MdiActiveDocument;<br />     Database db = doc.Database;<br />     Editor ed = doc.Editor;<br /> <br />     PromptEntityOptions peo = new PromptEntityOptions("\nSelect a viewport: ");<br />     peo.SetRejectMessage("\nMust be a viewport...");<br />     peo.AddAllowedClass(typeof(Viewport), true);<br /> <br />     PromptEntityResult per = ed.GetEntity(peo);<br /> <br />     if (per.Status != PromptStatus.OK) return;<br /> <br />     using (Transaction Tx = db.TransactionManager.StartTransaction())<br />     {<br />         Viewport vp = Tx.GetObject(per.ObjectId, OpenMode.ForWrite) as Viewport;<br /> <br /> <br />         db.UpdateExt(true);<br /> <br />         double scrRatio = (vp.Width / vp.Height);<br /> <br />         Matrix3d matWCS2DCS = Matrix3d.PlaneToWorld(vp.ViewDirection);<br /> <br />         matWCS2DCS = Matrix3d.Displacement(vp.ViewTarget-Point3d.Origin) * matWCS2DCS;<br /> <br />         matWCS2DCS = Matrix3d.Rotation(-vp.TwistAngle,<br />                                         vp.ViewDirection,<br />                                         vp.ViewTarget)<br />                                         * matWCS2DCS;<br /> <br />         matWCS2DCS = matWCS2DCS.Inverse();<br /> <br />         Extents3d extents = new Extents3d(db.Extmin, db.Extmax);<br />         extents.TransformBy(matWCS2DCS);<br /> <br />         double width = (extents.MaxPoint.X - extents.MinPoint.X);<br /> <br />         double height = (extents.MaxPoint.Y - extents.MinPoint.Y);<br /> <br />         Point2d center = new Point2d((extents.MaxPoint.X  + extents.MinPoint.X)*0.5,<br />                                      (extents.MaxPoint.Y  + extents.MinPoint.Y)*0.5);<br /> <br />         if (width > (height * scrRatio))<br />             height = width / scrRatio;<br /> <br />         vp.ViewHeight = height;<br />         vp.ViewCenter = center;<br /> <br />         Tx.Commit();<br />     }<br /> }<br />

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