[whatwg] Canvas "coordinate space units"

Oliver Hunt oliver at apple.com
Wed Jul 14 17:49:44 PDT 2010


On Jul 14, 2010, at 5:29 PM, David Flanagan wrote:

> Aryeh Gregor wrote:
>> On Wed, Jul 14, 2010 at 3:03 PM, David Flanagan <david at davidflanagan.com> wrote:
>>> I'm confused by the term "coordinate space units" as applied to the canvas
>>> spec.  It does not seem to be defined.
>> It seems clear to me.  
> 
> Even if clear, it is still undefined.  And the words "coordinate space" are so generic as to be meaningless here.  "canvas units" or something would make more sense.
> 
> The 2D context represents a Cartesian plane,
>> and the units for everything are units within that plane.  One
>> coordinate space unit might correspond to any number of pixels,
>> depending
<snip>
> As an aside, do you think any implementations actually do that?  It seems to me that it would cause real problems with drawImage(): images would look bad compared to drawn graphics...

WebKit supports device != css coordinates in its canvas implementation -- if you use QuartzDebug on Mac to change the resolution multiplier it causes a higher resolution backing buffer to be used.

--Oliver




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