[whatwg] Need clarification on DOM exceptions thrown by canvas 2D drawImage
ian at hixie.ch
Mon Aug 8 13:58:03 PDT 2011
On Mon, 8 Aug 2011, Justin Novosad wrote:
> This inquiry is regarding this page of the specification:
> In section 188.8.131.52.10 Images, about drawImage(), it is stated that "If
> one of the sw or sh arguments is zero, the implementation must raise an
> INDEX_SIZE_ERR exception" There are no other references to other
> circumstances under which INDEX_SIZE_ERR should be thrown, and there is
> no indication of what the correct behavior is when the source rectangle
> is completely or partially outside the bounds of the source image.
A bit lower down in the same section, the spec says: "When the filtering
algorithm requires a pixel value from outside the original image data, it
must instead use the value from the nearest edge pixel. (That is, the
filter uses 'clamp-to-edge' behavior.)"
Ian Hickson U+1047E )\._.,--....,'``. fL
http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,.
Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
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