如何获取AUTOCAD图形边界坐标

By Xiaodong Liang

Issue

I can set image’s clip by AcadRasterImage.ClipBoundary, but how do I get the AcadRasterImage's clip boundary coordinates? I know if it is

rectangular, I can get its bounding box, width and height. But, if the clip boundary is of a irregular shape, I can't find any exposed methods to get such data.

Solution

The ObjectARXAcDbRasterImage::clipBoundary() equivalent functionality is not exposed in the current ActiveX Automation Model.

We can work around this limitation by exposing an interface that does exactly that. The whole project is attached: Download ImgClipBoundary

STDMETHODIMP CClipBoundaryObj::GetImageClipBoundary( VARIANT* pVarDblArray, VARIANT acadImage) {

// TODO: Add your implementation code here try {

CComQIPtr

pAcadImage(acadImage.punkVal); if(!pAcadImage) throw E_POINTER; CComQIPtr pBaseObj(pAcadImage); if(!pBaseObj)

throw E_POINTER; AcDbObjectId id;

pBaseObj->GetObjectId(&id);

AcDbObjectPointer pImage(id, AcDb::kForRead);

if(pImage.openStatus() != Acad::eOk) throw E_UNEXPECTED; AcGePoint2dArray array = pImage->clipBoundary();

int len = array.length(); if(len == 0) throw E_FAIL;

AcGeMatrix3d mat;

pImage->getPixelToModelTransform(mat); mat.inverse();

AcAxPoint2dArray pts; for(int i=0; iAcGePoint3d pt(array[i].x, array[i].y, 0); pt.transformBy(mat);

pts.append(AcGePoint2d(pt.x, pt.y)); }

pts.setVariant(pVarDblArray); }

catch(const HRESULT h) {

// for now

acutPrintf(_T(\"\\nSomething is wrong.\")); return h; }

return S_OK; }

To use the ability above,

1.build the attached project, load it in AutoCAD 2. open VBA IDE

3. Tools >> Reference: select ARX. now you can see one library is available in the list.

4. Run the VBA code below. It creates an image and set its clip, and gets its clip boundary by the method provided in asdkImgClipBoundary.

Sub Example_ClipBoundary()

' This example adds a raster image in model space. ' It then clips the image based on a clip boundary.

' This example uses the \"downtown.jpg\" found in the sample ' directory. If you do not have the image, or it is located ' in a different directory, insert a valid path and name for the ' imageName variable below. Dim insertionPoint(0 To 2) As Double Dim scalefactor As Double Dim rotationAngle As Double Dim imageName As String

Dim rasterObj As AcadRasterImage

imageName = \"C:\\01_SDK\\ObjectARX 2012\\samples\\graphics\\AsdkTransientGraphicsSampFolder\\Airport-Image.jpg\" insertionPoint(0) = 5#: insertionPoint(1) = 5#: insertionPoint(2) = 0# scalefactor = 2# rotationAngle = 0 On Error Resume Next

' Creates a raster image in model space

Set rasterObj = ThisDrawing.ModelSpace.AddRaster(imageName, insertionPoint, scalefactor, rotationAngle) If Err.Description = \"Filer error\" Then

MsgBoximageName& \" could not be found.\" Exit Sub End If ZoomAll

MsgBox \"Clip the image?\ ' Establish the clip boundary with an array of points Dim clipPoints(0 To 9) As Double clipPoints(0) = 6: clipPoints(1) = 6.75 clipPoints(2) = 7: clipPoints(3) = 6

clipPoints(4) = 6: clipPoints(5) = 5 clipPoints(6) = 5: clipPoints(7) = 6 clipPoints(8) = 6: clipPoints(9) = 6.75 ' Clip the image

rasterObj.ClipBoundaryclipPoints ' Enable the display of the clip

rasterObj.ClippingEnabled = True ThisDrawing.RegenacActiveViewport

'MsgBox \"The image has been clipped.\ On Error GoTo 0

Dim xObj As asdkImgClipBoundaryLib.ClipBoundaryObj

Set xObj = ThisDrawing.Application.GetInterfaceObject(\"ImgClipBoundary.ClipBoundaryObj.1\") Dim boundary As Variant

xObj.GetImageClipBoundary boundary, rasterObj End Sub

Posted at 11:13 PM

in .NET, 2010, 2011, 2012, 2013, ActiveX, AutoCAD, ObjectARX, Xiaodong Liang | Permalink |Comments (2)