Visual C concept: Transplant and Upgrade MS-Help: //ms.msdnqtr.2003feb.2052/vccore/html/_core_graphics_functions.htm Most of the Windows 3.x API functions returned to the merged X- and Y-coordinate in Windows In the 3.x, the X- and Y-coordinates are 16 bits and are combined into a 32-bit (DWORD) function returns value, which is the largest effective size. In Win32, both coordinates are 32 bits, a total of 64 bits, so too large and cannot be placed in a single return value. Each Windows 3.x function is replaced with the same name's Win32 function, but adds an EX suffix. The EX function uses additional parameters instead of the return value to deliver X- and Y-coordinates. These new functions are supported by Win32 and Windows 3.x. There are two groups of graphical functions. The first group is a function of setting coordinates, which are listed together with Win32 versions in the following table. Portable versions of Windows 3.x function function MoveTo MoveToEx OffsetViewportOrg OffsetViewportOrgEx OffsetWindowOrg OffsetWindowOrgEx ScaleViewportExt ScaleViewportExtEx ScaleWindowExt ScaleWindowExtEx SetBitmapDimension SetBitmapDimensionEx SetMetaFileBits SetMetaFileBitsEx SetViewportExt SetViewportExtEx SetWindowExt SetWindowExtEx SetWindowOrg SetWindowOrgEx the first column of each function return values, although often ignored by the program code. However, even if the return value is not concerned, the old function call must be replaced with new forms. Win32 does not support the old function. Each EX function contains an additional parameter pointing to the data receiving location. After the function is called, this data provides information as the return value of the corresponding function. If this information is not required, you can pass NULL to this parameter. Under Windows 3.x, you can write MoveTo function calls as follows: MoveTo (HDC, X, Y); MoveTo calls are rewritten in the portable versions supported by both Windows versions. Note that the information returned by MoveToEx is ignored: MoveToex (HDC, X, Y, Null); the general rule is to pass NULL as the last parameter unless you need to use the X- and Y-coordinates returned by Windows 3.x. In the latter case, the process outlined in several paragraphs of the GET function is used.
