A couple of points that are unclear and are causing differences between current implementations (which is presumably a bad thing):
"interface HTMLCanvasElement" says "attribute long width;". #reflect says "If a reflecting DOM attribute is a signed integer type (long) then the content attribute must be parsed according to the rules for parsing signed integers first", which seems to apply in this case. But the canvas section says of width/height, "The rules for parsing non-negative integers must be used to obtain their numeric values". Hence, conflict. Also, "canvas.width = -1" is acceptable for a signed long, but doesn't make sense here. (After setting that, Firefox gives canvas.width==0, Opera gives 300, Safari gives -1.) What should happen when Infinity or -Infinity or NaN are passed as float arguments? I assume there shouldn't be a type exception since they're perfectly valid floats (under the usual models of floating point arithmetic), though I don't know where/if that's defined. In some cases there is a logical behaviour (e.g. when translating a finite-sized object by infinity, or scaling an object like rect(-10,-10,20,20) by infinity then clipping it to the viewable area), but in most cases there isn't (e.g. rotating by infinity, or doing anything with NaN, when the output depends on those values). My experience with some 3d canvas code is that infinities come up in naturally harmless places, e.g. having a function that scales by x then translates by 1/x and wanting it to work when x=0 (which ought to draw nothing, since anything it draws is zero pixels wide), and it's a bit annoying to track down and fix those issues, so I'd probably like it if they were harmless in canvas methods. Opera appears to silently not draw anything if the transformation matrix is not finite, but Firefox throws exceptions when passing in non-finite arguments. And some minor issues with the text: "DOMString toDataURL();" has the link stretching across the brackets. In "interface CanvasRenderingContext2D", it looks like "HTMLCanvasElement canvas;" should be "readonly attribute HTMLCanvasElement canvas;" (because everything else has "attribute", and the comment says it's readonly). "When the context is created, the transformation matrix must initially be the identity transform. It may then be adjusted using the three transformation methods" - but there are now five (not three) transformation methods (scale, rotate, translate, transform, setTransform). In Compositing, "darker" says "destination images" while all the others say "destination image". -- Philip Taylor [EMAIL PROTECTED]
