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Gear Sample

Source code for Gear 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. Gear is an MFC dialog-based application which displays simplified model of a gear using KernelCAD ActiveX control and allows to modify geometrical parameters of the model.

Gear is rather advanced sample. It demonstrates usage of tree-tier design which includes Geometry layer. This sample differs form Turbine  sample by more realistic and hence more complicated geometry of the model.

Implementation

While analyzing the implementation it is recommended to keep the Gear.glm model open in 3D Debugger to compare. It is even better to use the debugger to watch actual sequence and logic of the application and the parameters returned by the KernelCAD interfaces.

Roles of classes:

CGearDlg - implements the GUI layer. CGearDlg does not know anything about the geometry of the model. It just displays parameters, takes their new values and passes it to the Geometry layer. This work is done in CGearDlg::UpdateObject() method. It also takes display parameters from the geometrical layer and updates the dialog. This is done by CGearDlg::UpdatePage().

Gear class. Gear class implements geometrical layer of the application. It keeps most important parameters of the geometry, which are familiar and useful to the End User . It also knows how to converts these parameters into calls to KernelCAD software interfaces. Another role of the geometry layer is to validate and handle invalid user input.

Note that for simplicity there is no extensive validation of user input. In a real application assertions in implementation should be replaced with more comprehensive input validation and error handling.

See also: All C++ Samples,   All samples