devil help needed

[g666]

Ok all i want to do is load images into textures for a 2d game using devil, i want the origin of the images to be at the top left.

My problems are:

Why on earth do some image formats get loaded upside down when others dont?

How do i make alpha work?

[anarchotron]

To flip the image, use ILU.iluFlipImage() after your IL.ilBindImage() call.

To get alpha, just make sure you have the right format in IL.ilCopyPixels, e.g.:

ByteBuffer data = BufferUtils.createByteBuffer(numPixels * 4);
IL.ilCopyPixels(0, 0, 0, width, height, 1, IL.IL_RGBA, IL.IL_BYTE, data);

[g666]

How can i find out if i need to flip the image?

Games published by our own members! Check 'em out!

[anarchotron]

You just have to know what kind of data is incoming.  In my experience, artists & their tools like to think of the texture UVS at the bottom left & top right as 0,0 & 1,1, respectively.  OpenGL image space is flipped from this (0,1 & 1,0)... I flip all my incoming textures as a matter of course.  I also flip my modelview matrix into a left-handed coordinate system to be consistent with what most artists are used to.