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MiniCAD Sample

Source code for MiniCAD sample is available in Samples\VC folder of the installation directory. If you are going to compile the project we suggest to copy  whole VC  directory to location outside of the installation folder. MiniCAD is an MFC dialog-based application which displays DI model using KernelCAD ActiveX control and allows to modify geometrical parameters of the model.

See also:  C# MiniCAD Sample,   Visual Basic MiniCAD Sample,    Visual Basic .NET MiniCAD Sample,    All samples

Description of MiniCAD Sample

Implementation

Almost all functionality is implemented by MiniCADDlg class. Navigation through the interface hierarchy is the most important task. InitModelInfo() function retrieves m_pIModel pointer to IModel interface.

m_pIModel = (IModel*)m_ctrlCAD.GetModel();

 Interface to the current section is kept into m_pISection. It is obtained by UpdateSectInfo() function using call

    VERIFY( m_pIModel->GetSection(m_nCurSect, &m_pISection) == S_OK );

Note the call to Release() done on the current m_pISection. This is important because this UpdateSectInfo()  call is probably switching to another section which is another object and maintains its own reference counting.

The same function MiniCADDlg::UpdateSectInfo() acquires IAxiBase interface using call

m_pISection->QueryInterface( IID_IAxiBase, (void**)&m_pIAxiBase);

Prior to that we query the section type with

m_pISection->GetSectionType(szSectType);

to check if the section is a "3DSection". Otherwise it is a Surface of Revolution, which does not have base. We could have deduce it if QueryInterface call above for m_pIAxiBase have failed.

We can query two more interfaces, namely  I3DObject and IStrip from m_pISection. This is the last job done in MiniCADDlg::UpdateSectInfo(). Note that IStrip pointer m_pIStrip is implemented by object which represents cross-section segment strip in case of Generic 3D Section and profile segment strip in case of Surface Of Revolution.

Actual geometry changes are done in OnApply() function through IElement interfaces which are kept in m_pIElemJoint and m_pIElemSegment members. These are obtained by UpdateJointInfo() and UpdateSegmentInfo().