PRB: PlayMetaFile() Not as Fast as More Complex Technique

Last reviewed: July 22, 1997
Article ID: Q28344

3.00 3.10 WINDOWS kbprb kbprb

The information in this article applies to:

Microsoft Windows Software Development Kit (SDK) for Windows, versions 3.0 and 3.1

SYMPTOMS

The PlayMetaFile() function is slower than using a loop that contains the EnumMetaFile() and PlayMetaFileRecord() commands.

CAUSE

PlayMetaFile() takes longer because it plays the metafile records, and it also performs several additional steps:

Verifies that its handle parameter points to a valid metafile.
Locks the metafile.
Saves all objects in the device context (pens, brushes, regions, etc.).
Plays the metafile records.
Restores all objects in the display context. PlayMetaFile() will restore default objects if other restoration fails.
Unlocks the metafiles.
Deletes all objects created while playing the metafile.

To achieve this speed advantage, the callback function specified in EnumMetaFile() would call only PlayMetaFileRecord(). The actual speed of execution is determined by the amount of processing done in the EnumMetaFile() callback function.

Additional reference words: 3.00 3.10
KBCategory: kbprg kbprb
KBSubcategory: GdiMeta
Keywords : kb16bitonly

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Last reviewed: July 22, 1997
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