DOC: List of Functions That Are Valid in Metafiles

Pages 2-41 and 2-42 of the "Microsoft Windows Software Development Kit (SDK) Reference Volume 1" for version 3.0 list the subset of Windows GDI functions that an application can use in a metafile under Windows 3.0. The list printed in the manual is incorrect.

Page 107 of the "Microsoft Windows Software Development Kit: Programmer's Reference, Volume 1: Overview," lists the functions that are valid in a metafile for Windows 3.1. This list is incomplete.

This article provides a corrected list of functions that an application can use in a metafile under Windows 3.1.

The following list of functions that are valid in a Windows 3.1 metafile is taken from page 107 of the "Windows SDK: Programmer's Reference, Volume 1: Overview": The following table lists additional functions that are valid in a metafile under Windows 3.1: Although the following functions might function correctly in a metafile, they should not be used in a metafile: Windows has a number of functions that are not supported in metafiles directly because they are used to put an object into a metafile. The region functions are a common example of this function category. An application can create an arbitrary region, either directly or by combining existing regions. When an application selects the handle to the region into a metafile DC (display context), Windows records a CREATEREGION record into the metafile.

An application can select a bitmap into a memory DC that is compatible with the display (not directly into the metafile), and then then call the BitBlt function to move the bitmap from the memory DC into the metafile DC. Windows saves the bitmap image in the metafile as a Device-Independent Bitmap(DIB).

For more information, please refer to the online documentation for the Windows SDK or pages 106-109 of the "Windows SDK: Programmer's Reference, Volume 1: Overview" for version 3.1 manual.

* As a general rule, a metafile should be as device-independent as possible. Therefore, an application should not record into a metafile a GDI function that requires device units. Such functions include BitBlt, FillRgn, SetViewportExt, and SetViewportOrg.