[whatwg] More random comments on the putImageData definition
Oliver Hunt
oliver at apple.com
Wed Jan 23 02:07:29 PST 2008
Yet more commentary:
I noticed that the behaviour is undefined if putImagedata is provided
an ImageData object on which the width, height, or data member is a
getter that throws an exception.
A quick check shows that FFX3 throws a type mismatch -- eg. acts as
though the field was invalid.
Ooh, and a request for a feature. It would be great if putImageData
could take a source region, in addition to the destination. One of
the primary reasons for using get/putImageData is to allow JS to
rapidly blit data to the screen, however without an ability to blit
only a subregion of the image data the only available options are to
either re-blit the entire imagedata region (which can be expensive due
to the need for [un]premultiplying in some (all?) implementations), or
create and populate a new ImageData object which still requires more
work than would ideally be necessary.
--Oliver
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