FOCanvas File Format
Note: the formats described on this page are highly subject to change, see /ScratchPad for random ideas that are floating around
FOCanvas will Internally Use 2 Objects, an XCF of the current state, and an XML Form of all the changes, that format will be described in the following Section
XML ChangeSet Format
Note: This is what we will use in the ["../Protocol"] to send changes.
The format allows you to recreate the drawing from a blank canvas, it consists of Many ChangeSets. lets start with an example of a ChangeSet since those are always effective at giving an overview:
<ChangeSet author="Kyle" rev="10">
<Change width="100" height="40" hpos="90" vpos="1">(base-64 encoded pixel data)</Change>
<Change ...>...</Change>
...
</ChangeSet>Pretty straight Forward, but I'll explain it too:
ChangeSet Element
a ChangeSet Element represents a set of changes (duh), it contains any number of Change Elements, as well as author and rev Attributes, which are explained below (Off-Topic Note: typically in the protocol the client will send a single ChangeSet element which contains the changes since it last synced with the server)
Attributes:
author: the Author of the changes in the changeset, can be any UTF-8 string
rev: the Revision of said change, currently how this is used is undefined
Change Element
a Change Element represents a change, currently this element is highly subject to change since I havn't thought about this yet, but heres the explaination of the current attributes:
width, height: the width and height a change covers, yes a change must be rectangular
hpos, vpos: the horizontal and vertical position of the start of the change, starts at 1,1 in the upper-left corner