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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>1: My bad.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>2: Fair enough.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>3: Thanks, I had totally skipped the extra parameters available
on the drawImage function... oops. I think I’ll blog it so anyone else
who skim-reads the MDC will find my mistake on google when they search!<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:
"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;
font-family:"Tahoma","sans-serif"'> Oliver Hunt [mailto:oliver@apple.com] <br>
<b>Sent:</b> 04 June 2010 18:40<br>
<b>To:</b> Rob Evans<br>
<b>Cc:</b> whatwg@lists.whatwg.org<br>
<b>Subject:</b> Re: [whatwg] Canvas putImageData - Can we scale?<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>On Jun 4, 2010, at 10:05 AM, Rob Evans wrote:<o:p></o:p></p>
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<br>
<o:p></o:p></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Hi,<o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> <o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>
I wonder if this is the correct place to post this but I cannot find any
resources online as canvas is so new.<o:p></o:p></span></p>
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<p class=MsoNormal>Canvas isn't new -- it's at least 4 or 5 years old, and has
been in the html5 spec for at least 2 or 3 of those years -- I believe the MDC
has some of the best API documentation (at least in terms of providing examples
of how the APIs are used.)<o:p></o:p></p>
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<p class=MsoNormal><br>
<br>
<o:p></o:p></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> <o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>
After grabbing some image data from a canvas with the getImageData call, I
cannot find a way to put the image data onto a canvas scaled down.<o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> <o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>
If I use the canvas scale function and then put the image data, no scaling
occurs. Is there any way to scale with putImageData?<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>No. The ImageData API documentation is very clear on this,
and has not changed substantively in a few years now. get/putImageData
are not effected by the current CTM.<o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal><br>
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<o:p></o:p></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>
If not I think it would be a useful addition to the specification. I can
imagine many situations where copying a section of the canvas and applying
scaling before pasting it back to the canvas would be useful!<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>You shouldn't be using ImageData to do this --
CanvasRenderingContext2D.drawImage supports canvas elements, and has well
defined semantics for drawing the contents of a canvas element into its own
context -- in addition to supporting non-identity CTMs this is also likely
quite a bit faster in the identity case than an imagedata based approach.
Is there some specific reason you want to use the ImageData API?<o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>--Oliver<br>
<br>
<o:p></o:p></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> <o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Thanks,<o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> <o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Rob
Evans<o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>CTO<o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>mtn-i
LTD<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
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