I'm working on a new project that requires a few layers of blending (It's an OpenGL app), and I'm discovering that the PNG loader used by Bitmap seems to always load the PNG with premultiplied alpha. I've spent all evening confirming the values being saved out are correct, and the PNG spec itself declares that alpha should never be premultiplied.
I need to mask out background elements with a blend function like GL_ONE GL_ONE_MINUS_SRC_ALPHA, but the color math can't be done with premultiplied alpha... a lot of very useful blends go away in this case actually, and none of the other formats support a full alpha channel. I found a thread about this from over a year ago that pretty quickly reduced to an argument of the merits of premultiplied alpha vs non- premultiplied alpha. Is there any way to load a PNG file into an OpenGL texture without modifying the colors like this? -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
