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prajwalshetty
Visitor
‎07-08-2015 07:39 AM

How can we achieve a transparent background in image canvas

Hi All,

Is there a way we can achieve transparent background in image canvas using opacity or something like that when we draw a rectangle.

Regards,
Prajwal
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3 REPLIES 3
EnTerr
Roku Guru
‎07-16-2015 11:38 AM

Re: How can we achieve a transparent background in image can

This is hopelessly undocumented - but i will take a guess you can use color attribute for the rectangle?
If so, it is likely RGBA and by varying the Alpha channel between 0 and 255 you can get levels of transparency.
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TheEndless
Channel Surfer
‎07-23-2015 03:13 AM

Re: How can we achieve a transparent background in image can

"EnTerr" wrote:
This is hopelessly undocumented - but i will take a guess you can use color attribute for the rectangle?
If so, it is likely RGBA and by varying the Alpha channel between 0 and 255 you can get levels of transparency.

roImageCanvas colors are actually ARGB, but you are correct. Set the color to an ARGB value and set the CompositionMode to "Source_Over" and that will alpha blend the TargetRect over the underlying layers.
My Channels: http://roku.permanence.com - Twitter: @TheEndlessDev
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EnTerr
Roku Guru
‎08-13-2015 08:57 PM

Re: How can we achieve a transparent background in image can

"EnTerr" wrote:
This is hopelessly undocumented -

Documented 7/31 - thanks, RokuKC!
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