The METAFILEPICT structure defines the metafile picture format used for exchanging metafile data through the clipboard.
typedef struct tagMETAFILEPICT { // mfp LONG mm; LONG xExt; LONG yExt; HMETAFILE hMF; } METAFILEPICT;
For MM_ISOTROPIC and MM_ANISOTROPIC modes, which can be scaled, the xExt
and yExt members contain an optional suggested size in MM_HIMETRIC
units. For MM_ANISOTROPIC pictures, xExt and yExt can be zero
when no suggested size is supplied. For MM_ISOTROPIC pictures, an aspect ratio
must be supplied even when no suggested size is given. (If a suggested size is
given, the aspect ratio is implied by the size.) To give an aspect ratio
without implying a suggested size, set xExt and yExt to negative
values whose ratio is the appropriate aspect ratio. The magnitude of the
negative xExt and yExt values is ignored; only the ratio is
used.