Magnifying Glass - demonstrates different ways to obtain or create proper DC and use BitBlt - StretchBlt functions

Environment:VC5/VC6

Generally the sample demonstrates different ways to obtain or create proper DC and use BitBlt - StretchBlt functions.

It is another ZoomIn demo application created with doc-view architecture. CView derived class experienced minimum changes from AppWizard generated one.

CImageWnd window covers CView derived class window. CImageWnd contains a copy (mirror) of CView derived class window bitmap to draw. CImageWnd window becomes transparent when magnifying glass is inactive and draws a "lens" over the bitmap when active. The "lens" is a small zoom window. Magnifying Glass doesn't depend on a view contents. It is easy to modify CMgnView::OnDraw or CMgnView::OnEraseBkgnd and Magnifying Glass still will work with another contents.

To activate or deactivate magnifying glass - press button on a toolbar.

To magnify a portion of a view - activate magnifying glass, press left mouse button and move "lens" around a view.

To change magnifying glass size, shape or zoom - activate magnifying and click a view with right mouse button. It is possible to create several views just use file - new command. Note that for each view magnify glass keeps its own properties.

It is easy enough to make a "lens" astigmatic (cylinder) or add another "optical effects".

I couldn't remove some "optical side effects". When magnifying glass is slowly moved from outside a frame inside it over a border you see a "diffraction grid".

Download source - 27 Kb



Comments

  • There are no comments yet. Be the first to comment!

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Live Event Date: December 11, 2014 @ 1:00 p.m. ET / 10:00 a.m. PT Market pressures to move more quickly and develop innovative applications are forcing organizations to rethink how they develop and release applications. The combination of public clouds and physical back-end infrastructures are a means to get applications out faster. However, these hybrid solutions complicate DevOps adoption, with application delivery pipelines that span across complex hybrid cloud and non-cloud environments. Check out this …

  • VMware vCloud® Government Service provided by Carpathia® is an enterprise-class hybrid cloud service that delivers the tried and tested VMware capabilities widely used by government organizations today, with the added security and compliance assurance of FedRAMP authorization. The hybrid cloud is becoming more and more prevalent – in fact, nearly three-fourths of large enterprises expect to have hybrid deployments by 2015, according to a recent Gartner analyst report. Learn about the benefits of …

Most Popular Programming Stories

More for Developers

RSS Feeds