Canvas hack

[raphaelbastide]

Should we take a decision for this kind of hack or leave it as it is ?

• http://scri.ch/eah
• http://scri.ch/eak

[bpierre]

First, this is a useful feature: it enables canvas experimentations in
the browser (I often use scri.ch to do this without saving: var ctx =
document.getElementById('drawing').getContext('2d')). So this is
not really a hack, but this is not why we made scri.ch. Also, there is
no real reason to explicitely allow the saving of a photo for example
(the problem is the save functionnality, not the drawing).

Should we, and can we, add restrictions in order to prevent this usage?

With a path system (save the mouse path instead of the resulting
drawing), the second example would not be possible, but it would still
be possible to script the path (although some crazy algorithm could
try to detect non-human behaviors). There is no 100% reliable solution
to prevent scripted drawings, we can only make them more difficult
(some technologies are more closed by nature, like Flash :-[ ).

But I think that we should actually encourage this! Why would we
prevent users to build things upon scri.ch? We could use a path system
with an explicit JS API, to allow path scripting (bookmarklets, etc.).
Canvas experimentations would still be possible, but saving them would
not work anymore.