ambassador at fourthworld.com
Sun Sep 20 14:48:14 EDT 2009
Graham Samuel wrote:
> However Richard your other point:
>> The rect option can be useful at times, but since v2.7 we've had a
>> much easier and more robust method of exporting images of objects
>> by specifying the object itself rather than a rect:
>> import snapshot from img "MyImage"
>> The object needn't be an image; it can be anything other than a stack
>> (referencing the card will work for those), even groups.
>> The big difference is how the image is generated:
>> Using the rect option cips a portion of the display buffer, so if
>> your image is out of bounds there won't be anything to get.
>> But using an object reference causes the engine to render the object
>> into a private buffer for you, much like it would do when rendering
>> the image on a card, and then hands that buffer back to you in the
>> resulting image.
> Is not so easy to follow if you're trying to build up a composite
> image: say for the sake of argument one has a picture (an image)
> occupying some part of a card, and one imposes on top of it another
> image, with the intention of snapshotting the combined image so as to
> create a new picture that can be exported: it might be a jpg of a
> membership card with the member's picture imposed on it, or something
> like that. Then if I import a snapshot of my background image (the
> card design), won't my foreground image (the member's picture) be
> ignored? That's how I read the docs - so what I did in the end was to
> use a rect based on the background image, something like:
> import snapshot from rect (the rect of of img "MembershipCard")
> This worked, but it appeared to me that I had to have a window (card,
> stack) as big as the whole background image if nothing is to be
> clipped, which was inconvenient.
If you can put the objects you want into a group, this needn't affect
anything in your user experience and requires only small changes to your
script, but would let you use the robust one-liner to get the snapshot
of the group image even if outside of the clipping region of the window:
import snapshot from grp "MyCompositeThang"
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