Most CAD and drawing applications provide features that scale output created by the user. If your application requires scaling (or “zoom”) capabilities, you can use the SetWorldTransform function to set the appropriate world-space to page-space transformation. This function receives a pointer to an XFORM data structure which contains the appropriate values. The member eM11 specifies the horizontal scaling component and the member eM22 specifies the vertical scaling component.
The following illustration shows a scaled rendering of the house (The diagram was scaled to 1/2 its original size):
Scaled Front-View of House