Bug 724

Summary:	Loading transparent PNG without alpha channel into Texture
Product:	[JogAmp] Jogl	Reporter:	Alan Sambol <alan.zgb>
Component:	util	Assignee:	Sven Gothel <sgothel>
Status:	RESOLVED FIXED
Severity:	major	CC:	alan.zgb
Priority:	---
Version:	2
Hardware:	All
OS:	all
Type:	---	SCM Refs:	35fcf49d1cb49e3844e7cee44f34d827d8a102ce 51427b92a2d9cd3fc619854e26536c9c6adad947 f0c8d6cf5d7f8f64cea79b3d0d27e4db6ccef41e
Workaround:	---
Attachments:	Original PNG. Contains transparent background. Created in Adobe Photoshop.

Description Alan Sambol 2013-04-24 14:56:45 CEST

Created attachment 456 [details]
Original PNG. Contains transparent background. Created in Adobe Photoshop.

Loading the texture via following command doesn't work properly:
TextureIO.newTexture(getClass().getClassLoader().getResource("original.png"), false, "png");

Result can be seen here: http://forum.jogamp.org/file/n4029016/bar-left-rendered.png (don't mind the blue line and rotation, it's from another png).
It turns out yellow instead of gray.

If I use the following command it works fine:
BufferedImage img = ImageIO.read(getClass().getClassLoader().getResource("original.png"));
TextureIO.newTexture(AWTTextureIO.newTextureData(GLProfile.getDefault(), img, false));

The problem is I can't use AWTTextureIO on Android, which is one of our target platforms.

The original image is in attachment. It's a default png image created in Adobe Photoshop - with transparent background and no alpha channel - used for web and Jogl1 with no problems.

Comment 1 Sven Gothel 2013-07-03 11:50:01 CEST

1 Add manual unit test, incr. PNGImage verbosity.

2 PNGJ: Bump to git sha1 a0b1101ba2d37de39428ed55c8189502e24a3125 
  of https://code.google.com/p/pngj/

3 Testing PNG Transparency / Fixing GLSL Shader of test case: 
   Mix texture alpha properly (pre-multiply), due to lack of ALPHA_BLENDING.

'Works for me' .. i.e. w/ fixed GLSL shader respecting texture alpha,
the GL readBuffer produced the right data.

I don't think [2] has anything todo w/ it - but I don't like to test again.

Thank you for the test case (image), it is incl. in our unit tests now [1 and 3].
You might want to tune your shader code, or enable ALPHA blending ?!