Slick TextureData

[sirK]

Hello,

I have tried to find information on this topic, but have nothing found that can directly help me.
I am playing around with RGBA manipulation of textures. Or lets say I try. I just can't seem to figure out how to use the Data that is provided by getTextureData().
I do something like:

tex = TextureLoader.getTexture("PNG", ResourceLoader.getResourceAsStream("res/test_small.png"));
byte[] texData = tex.getTextureData();

But when printing this array I cannot seem to understand the pattern behind it to unlock the information that I'm searching for (mainly the alpha channel of every pixel).
There are many negative numbers, so I fear there may be somthing wrong, since I expected to find values between 0 and 256.

Maybe one of you can help me with this problem.

Thanks,
sirK

[Fool Running]

That is actually correct. Java bytes seem to be converted as signed bytes instead of unsigned bytes. The negative values you are seeing are actually the byte values from 128-255.
See http://www.crazysquirrel.com/computing/java/basics/how-to-convert-bytes.jspx if you need to manipulate them as integers.

[sirK]

Ah ok, I see. Right, have forgotten about the signed byte thing in Java. Haven't programmed a while in java, so I obviously got confused there.
Well, thanks for the quick response. That helps a lot.