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Q145696: FIX: CDC::CreatePointFont() May Create Wrong Size Font

Article: Q145696
Product(s): Microsoft C Compiler
Version(s): 4.0
Operating System(s): 
Keyword(s): kbcode kbDocView kbFont kbGDI kbMFC kbVC400bug kbVC410fix kbNoUpdate
Last Modified: 20-OCT-2001

-------------------------------------------------------------------------------
The information in this article applies to:

- The Microsoft Foundation Classes (MFC), used with:
   - Microsoft Visual C++, 32-bit Editions, version 4.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

Calling CDC::CreatePointFont() results in a font that is not of the point size
requested. This will occur when the y component of the DC's viewport origin is
not at 0. A common place for this to occur would be in a CScrollView class where
the user has scrolled the view vertically.

CAUSE
=====

MFC uses DPtoLP() to map the given device coordinates to logical coordinates.
The case where the viewport origin is not at 0 is not taken into consideration
by this code.

RESOLUTION
==========

Set the y component of the viewport origin to 0 before calling
CreatePointFont(). The following code demonstrates the workaround. Here pDC is a
pointer to a CDC.

Sample Code
-----------

  /* Compile options needed: default
  */ 
  POINT pt;
  SetViewportOrgEx(pDC->GetSafeHdc(), 0, 0, &pt); // set origin to 0,0
  CreatePointFont(120, "Courier", pDC);
  SetViewportOrgEx(pDC->GetSafeHdc(), pt.x, pt,y, NULL); // restore origin

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug was corrected in Visual C++ 4.1.

Additional query words: kbVC400bug 4.10 4.00

======================================================================
Keywords          : kbcode kbDocView kbFont kbGDI kbMFC kbVC400bug kbVC410fix kbNoUpdate 
Technology        : kbAudDeveloper kbMFC
Version           : :4.0
Issue type        : kbbug
Solution Type     : kbfix

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