Nearest Point
Posted: 20 Oct 2005, 07:56
When the user clicks the mouse button, how can I calculate the nearest point or intersection? I basically need to figure out snapping the mouse like in AutoCad.
Step 1.
Call <b>TsgDXFImage.GetCADCoords</b> function for obtaining real coordinates of entities.
For example:
Code: Select all
<b>var</b>
vRect: TRect;
<b>begin</b>
...
vRect := FImage.PictureRect;
RealPoint := TsgDXFImage(FImage.Picture.Graphic).GetCADCoords(X / (vRect.Right - vRect.Left), (FImage.Height - Y) / (vRect.Bottom - vRect.Top))
<i>RealPoint</i> is an instance of <i>TFPoint</i>;
FImage is an instance of <i>TImage</i> or <i>TsgDXFImage</i>;
<i>X</i>, <i>Y</i> are the mouse coordinates above <i>FImage</i> obgect in pixels.
Step 2.
Call <i>TsgDXFConverter.Iterate(Proc: TsgCADEntityProc; var Params: TsgCADIterate)</i> for getting access to every entity and its data.
<b><i>procedure</b> ReadCADEntities(Entity: TsgDXFEntity);</i> - this is a user's procedure which gets entities one by one while iterating. There is an example in in SimpleImport demo in CADImportVCL\Delphi\Demos\SimpleImport folder(http://www.cadsofttools.com/download/CADImportVCL.zip).
<i>FCADParams: TsgCADIterate;</i> - returned iteration parameters
<i>Converter.Iterate(ReadCADEntities, FCADParams);</i> - call this procedure to start iteration.
Sergey.
please post questions to the forum or write to support@cadsofttools.com