System Window Mask Stack (Keyhole effect for stack with Windowshape)

[David Bovill]

I’m trying to create a stack which I place in front of stacks which contain browser objects and camera controls in order to mask them and create more interesting shapes for the video and browser content. The only way to do this I believe is to have a stack - let’s call it a “System Window Mask” stack - and punch holes though it. A stack level keyhole effect.

Scott if you are there I need your help :)

This stack of Scotts shows the result:

• go url "http://www.tactilemedia.com/download/animated_mask.livecode"

And I’d like a way to generate those masks from graphic objects that I place on the “System Window Mask” stack - then export a snapshot - my experiments so far are failing.

I can get a polygon to make the stack with code like this:

• export snapshot from graphicObject with effects to img”mask” of me as PNG
• set the windowshape of stack stackName to imageID

But I’d like to reverse the effect - so I get a hole in the shape of the graphic. Code like this:

-- set the ink of graphicObject to "blendDstIn"
-- set the ink of myGroup to "blendSrcOver"

Before taking the snapshot is not cutting it?