[CREATE] OpenRaster clarifications

[Calle Laakkonen]

Hello.
I am the developer of DrawPile, which is an online collaborative drawing 
program. I just added a simple implementation of OpenRaster as DrawPile's 
default format. It appears to be compatible with MyPaint, but I haven't tried 
it with Krita yet.
There are a few ambiguities in the specification I'd like to confirm, however.

First, layers and nested layer stacks have coordinates which default to 0. I 
assume these are relative to the parent element? For example if a have a 
layer stack like this:
<stack>
	<stack x="10" y="10">
		<layer x="-5" y="0"/>
	</stack>
</stack>
In this case, is (5, 10) the real position of the layer or are all coordinates 
absolute?

Second question is about the size attributes. If a size has been explicitly 
defined for a layer and it differs from the actual size of the source data, 
should the image be resized or cropped to fit the layer or should the 
manually defined size be ignored? Likewise, how should a stack whose size 
differs from the computed size of its contents be treated?

Third, what is the range of the opacity property? I assume it is 0.0 to 1.0, 
but this isn't specified anywhere in the OpenRaster docs. It would also be 
nice to have an attribute to mark a layer as hidden independant of its 
opacity.

Finally, what's the status of the text element currently? DrawPile has 
annotations, which are pretty much equivalent to text layers in other 
programs (except that DP annotations always float on top of the image), so 
naturally I'd like to be able to save those as well.

	-Calle