Double Buffering technique in MFC for Flicker Free drawing

Visual Programming

Flickering is caused in a window,  by painting,  in two steps.

(1) Erasing the window contents in OnEraseBkgnd.  By default MFC does this.

(2) Painting new contents in OnPaint or OnDraw.

Double buffering eliminates this two-step process by overriding OnEraseBkgnd and including the erase in OnPaint/OnDraw to an off-screen image.

1. Overriding the OnEraseBkgnd function:

  • Add a message handler for WM_ERASEBKGND in your Windows application.
  • Once added it looks like the below one:
  • BOOL CExampleView::OnEraseBkgnd(CDC* pDC) 
    {
          // TODO: Add your message handler code here and/or call default
          return CView::OnEraseBkgnd(pDC);
    }
    
    Now change the return value to any non-zero value and comment the default proced-ure.
    BOOL CExampleView::OnEraseBkgnd(CDC* pDC) 
    {
          return TRUE;
    }

2. Now In the OnPaint/OnDraw do the following steps:

1.  Create a Memory DC for the View DC as below:

               CreateCompatibleDC(pDC);

2.   Create the bitmap in memory…

View original post 78 more words

Advertisements

About Khuram Ali

Programming... Programming and Programming...!!!

Posted on August 22, 2013, in Windows Programming. Bookmark the permalink. Leave a comment.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: