Xojo Conferences
MBSOct2019CologneDE

DynaPDF Manual - Page 159

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Function Reference
Page 159 of 767
pdfSetExtGState(pdf, gsHandle);
// Activate the wished settings
pdfPlaceTemplate(pdf, grp, ...); // Insert the group
pdfSetExtGState(pdf, defGState); // Restore the changes made before
When entering a transparency group a viewer initialized the fill and stroke alpha to 1.0 and sets the
blend mode to bmNormal so that the transparency is not applied twice (one time on the entire group
and one time on the objects in it). If the group represents a soft mask, the current soft mask is also
explicitly deactivated before the group will be drawn.
If a soft mask should be applied on the group then the group should disable the current soft mask as
the first command or before drawing the first object. Otherwise the mask is applied twice, one time
on the entire group and another time on the objects in it.
Remarks:
It is bad practice to place a transparency group into an active clipping path or to activate a soft mask
in a clipping path. Clip the contents inside the group but don't clip the group itself! A viewer must
mostly adjust the clipping path so that it remains valid. This operation can be very computation
intensive and should be avoided.
Return values:
If the function succeeds the return value is the template handle, a value greater or equal zero (a
transparency group is an extended template). If the function fails the return value is a negative error
code.
 

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