DynaPDF Manual - Page 180

Previous Page 179   Index   Next Page 181

Function Reference
Page 180 of 839
pdfEndTemplate(pdf, ...);
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.
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

Previous topic: Isolated and Non-Isolated Groups, Knockout Groups, Color Spaces, How to use a Transparency Group?

Next topic: Bezier_1_2_3