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AppGameKit Classic Chat / SaveImage results in png image without alpha?

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Naphier
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Location: St Petersburg, Florida
Posted: 11th Jul 2014 21:11
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So if I create an image with GetImage the resulting sprite has an alpha channel, but when I save the image the alpha channel is black.
Am I missing a setting?


Thanks!

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Marl
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Location: Bradford, UK
Posted: 12th Jul 2014 17:05
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This probably one for Paul, but you could double check the sprite alpha is coming from the image alpha channel (rather than just being a transparent colour) by making a second image from the alpha channel and saving that.
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Van B
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Posted: 17th Jul 2014 09:53
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To get alpha on bitmaps (which your reading the image from), try using BITMAP FORMAT 21 at the start of your program.

A bit obscure I know, but I think that will do the trick.

I am the one who knocks...
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Naphier
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Posted: 17th Jul 2014 10:06
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Thanks but just gave that a go and the compiler doesn't understand it. Looks like a DBPro command.

No worries though, I just decided not to save the image to the drive. I really only need it for a single image in my current project so it's not a big deal.

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Van B
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Posted: 17th Jul 2014 13:42
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Ach, for some reason I thought this was DBPro, sorry about that.

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MASTER OF PUPPETS
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Posted: 18th Jul 2014 14:11 Edited at: 18th Jul 2014 14:14
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Perhaps you won't use it, but maybe we can solve the issue on this thread. That way, anyone that stumbles across this thread while searching for a solution, may find the answer here. I placed this modified code at the beginning of a program:



In "Document/AGK/[-project name here-]", I find that it creates a white 32*32 pixel box in a 64*64 pixel image. The alpha channel appears as it should (in quadrants 1 , 3 ,and 4). Are these results repeated with you guys?

|,,|, (Dead Knot Broken) ,|,,|
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Naphier
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Location: St Petersburg, Florida
Posted: 18th Jul 2014 18:33
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Thanks for getting me to stab at this again.
So here's what happens:
Your code works just fine, but if you introduce any other sprites, like a background sprite it also gets caught in the image.
Why? Apparently, Render()...
So all we need is
CreateSprite
ClearScreen
DrawSprite
GetImage

Then it works like a charm no matter what other sprites you already have. I've still decided to not save my image because the image created is non-power of 2 and to ensure that it is AND generate a subimages.txt file just isn't worth the extra work for a single image. Maybe someday I'll work up a nice API for doing something like this with multiple images being packed into an atlas in the future.

Cheers!

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