Roku Developer Program

Join our online forum to talk to Roku developers and fellow channel creators. Ask questions, share tips with the community, and find helpful resources.
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
xtr33me
Visitor

Any requirements for images drawn on screen?

I have not had luck finding this and was wondering if there was some documentation somewhere describing what can and cant be rendered to screen. The reason I ask is I am displaying data in a tabular fashion using roCanvas. I wanted a graphical background to display behind the text I am printing to screen but when I use the png image I created in photoshop with a size of 1280x720 and a transparency layer, I get nothing. However if I use a smaller graphic, that does not have transparency, the image shows up. I am assumign this is a restriction onthe device and was hoping I could better find what is allowed. Any help would be great. Thanks!

pics = []
pics.Push({
url: "pkg:/artwork/travel.png"
targetRect: m.canvas.GetCanvasRect()
})
m.canvas.ClearLayer(3)
m.canvas.SetLayer(2,pics)
m.canvas.SetLayer(3, m.decodedText["sid"])
0 Kudos
3 REPLIES 3
TheEndless
Channel Surfer

Re: Any requirements for images drawn on screen?

What does "m.decodedText["sid"]" look like? Presumably, it's not just a string, as that's not the correct format for a text layer on roImageCanvas.

Also, for your pics, if you want transparency, try setting the CompositionMode to "Source_Over" to enable alpha blending (http://sdkdocs.roku.com/display/sdkdoc/ ... +Meta-Data).
My Channels: http://roku.permanence.com - Twitter: @TheEndlessDev
Instant Watch Browser (NetflixIWB), Aquarium Screensaver (AQUARIUM), Clever Clocks Screensaver (CLEVERCLOCKS), iTunes Podcasts (ITPC), My Channels (MYCHANNELS)
0 Kudos
xtr33me
Visitor

Re: Any requirements for images drawn on screen?

"TheEndless" wrote:
What does "m.decodedText["sid"]" look like? Presumably, it's not just a string, as that's not the correct format for a text layer on roImageCanvas.

Also, for your pics, if you want transparency, try setting the CompositionMode to "Source_Over" to enable alpha blending (http://sdkdocs.roku.com/display/sdkdoc/ ... +Meta-Data).


Thanks for the reply. First off, the decodedText["sid"] is pointing to an AA as shown below. I appologize as that wasn't supposed to make the copy and paste, as the issue I am having right now is with the pics portion 🙂 Regardless, I did try using sourc_over as well yesterday and wasn't having any luck with my image coming up. Is it ok if my image has a transparency layer to begin with? I have no problem getting a black square to be transparent by changing the alpha in the color, but have not had luck with this image. I am going to be playing with this some more today so I will post here anything new I find.

arr["sid"] = CreateObject("roAssociativeArray")
arr["sid"]["targetRect"] = {x: decodedTextStartPoint.x, y: decodedTextStartPoint.y, w: tableWidths.wCol1, h: tableHeight}
arr["sid"]["textAttrs"] = textAttr
arr["sid"]["text"] = ""
0 Kudos
xtr33me
Visitor

Re: Any requirements for images drawn on screen?

All this time on this thing, tryin to get it to work and a simple clean and rebuild seems to have fixed it. I should have tried the simple things first 😛 Anyways, thanks for the help. Using "Source_Over" does work and something must have just not been getting packaged right.
0 Kudos
Need Assistance?
Welcome to the Roku Community! Feel free to search our Community for answers or post your question to get help.

Become a Roku Streaming Expert!

Share your expertise, help fellow streamers, and unlock exclusive rewards as part of the Roku Community. Learn more.