Better alpha-transparency support in drawImage

[GoogleCodeExporter]

From

https://sourceforge.net/tracker2/?
func=detail&aid=1728895&group_id=163391&atid=827562

I have written some testcases (See attached ZIP) which shows that
alpha-transparency support of the drawImage() function is pretty bad in
current excanvas. Looks like IE is doing nasty things with rotated or
scaled vml:image tags.

So I replaced the VML tags with DIVs using the AlphaImageLoader and now all
the testcases are looking much better.

The changed excanvas.js together with a patch against the current SVN
version is also in the attached ZIP.

Here you can see the testcases in action:

With original excanvas.js:

http://www.ailis.de/~k/permdata/20070531/excanvas/testcases/drawimage/index
-orig.html

With modified excanvas.js:

http://www.ailis.de/~k/permdata/20070531/excanvas/testcases/drawimage/index
.html

Due to the lack of existing testcases I'm not sure if my changes broke some
more complex scenarios. There is some code in the drawImage() method I
don't understand so if you consider to apply my patch please do more
testing and code-cleanups.

Original issue reported on code.google.com by erik.arv...@gmail.com on 22 Mar 2009 at 12:28

[GoogleCodeExporter]

Hello, I'm facing the exact same issue.
I wanted to try your patch but it is not attached to the bug and the link to 
sourceforge is dead.
Could you upload it ?
Thanks a million !

Original comment by cedric.m...@gmail.com on 4 Oct 2010 at 10:03

[GoogleCodeExporter]

My bad...
Got it from http://www.ailis.de/~k/permdata/20070531/excanvas/excanvas.js

Original comment by cedric.m...@gmail.com on 4 Oct 2010 at 12:31