[Solved] PNG Alpha Transparency on SDL Android

BlitzMax Forums/Brucey's Modules/[Solved] PNG Alpha Transparency on SDL Android

RustyKristi

(Posted 2016) [#1]

This has been tested on desktop to be working but when building on android there's no transparency and it's black background instead.

Can someone confirm on this? thanks

RustyKristi

(Posted 2016) [#2]

MASKEDIMAGE works btw but it does not look good.

Derron

(Posted 2016) [#3]

Works here as intended.

- I opened up "Dig/samples/interpolation"
- copied "start_logo.png" from "Dig/samples/_res" into this directory
- opened up "interpolation.bmx" and appened after the latest import:

Import brl.ramstream
Import Brl.PNGLoader
Incbin "start_logo.png"

After "setBlend" I added:

Local img:TImage = LoadImage("incbin::start_logo.png",0)

Then I added right before the first "If KeyHit":

	For Local i:Int = 0 To 15
		SetColor i*20, i*20 + 55,i*20
		DrawRect(GraphicsWidth() - i*(img.width/15), GraphicsHeight() - img.height,(img.width/15), img.height)
	Next
	SetColor 255,255,255
	DrawImage(img, GraphicsWidth() - img.width, GraphicsHeight() - img.height)

Result was like intended: slight shadow of the text was displayed, so no simple "1 color transparency" but a real alpha channel usage.

bye
Ron

Derron

(Posted 2016) [#4]

BTW: instead of incbin, you could also copy the image to "assets" within the newly created "android-project-interpolation".

You then could load the image via:

Local img2:TImage = LoadImage("sdl::start_logo.png",0)

You might need to "import Sdl.sdl" first.

bye
Ron

RustyKristi

(Posted 2016) [#5]

Thanks Derron! :D I will try this asap..

RustyKristi

(Posted 2016) [#6]

Ok so I finally got it after doing some tests. If I'm not mistaken that for alpha png images you need to SetColor to white (255,255,255) before you load the image.

I don't know or I have yet to find a manual or online docs showing this method but I'm glad to have solved this issue so thanks again! :D