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 dialogue-based application which
displays DI model using DG Kernel 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
entity is kept into m_pIEntity. It is obtained by UpdateSectInfo() function
using call
VERIFY( m_pIModel->GetEntity(m_nCurSect, &m_pIEntity) == S_OK );
Note the call to Release() done on the current m_pIEntity. This is important
because this UpdateSectInfo() call is probably switching to another entity which is
another object and maintains its own reference counting.
The same function MiniCADDlg::UpdateSectInfo() acquires IAxiBase
interface using call
m_pIEntity->QueryInterface( IID_IAxiBase,
(void**)&m_pIAxiBase);
Prior to that we query the entity type with
m_pIEntity->GetEntityType(szSectType);
to check if the entity 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_pIEntity. This is the last job done in
MiniCADDlg::UpdateSectInfo(). Note that IStrip pointer m_pIStrip is
implemented by object which represents cross-entity segment strip in case of
Generic 3D Entity 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().
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