I'm currently working on a program that stores RGB-info from two images to compare them.
I created two example images with paint.net. Both are 16x16 and one is BLUE and the other one is RED. I set the value in paint.net to (255, 0 ,0) in the RGB value for RED and in the blue image to (0,0,255).
As I loaded it into a ByteBuffer and looked inside it.
// Buffer for texture data
ByteBuffer res = BufferUtils.makeByteBufferT4(w * h);
// Convert pixel format
for (int y = 0; y != h; y++) {
for (int x = 0; x != w; x++) {
int pp = bi.getRGB(x, y);
byte a = (byte) ((pp & 0xff000000) >> 24);
byte r = (byte) ((pp & 0x00ff0000) >> 16);
byte g = (byte) ((pp & 0x0000ff00) >> 8);
byte b = (byte) (pp & 0x000000ff);
res.put((y * w + x) * 4 + 0, r);
res.put((y * w + x) * 4 + 1, g);
res.put((y * w + x) * 4 + 2, b);
res.put((y * w + x) * 4 + 3, a);
}
}
public static ByteBuffer makeByteBufferT4(int length){
// As "int" in java has 4 bytes we have to multiply our length with 4 for every single int value
ByteBuffer res = null;
return res = ByteBuffer.allocateDirect(length * 4);
}
Via res.get(0) I expected 1 as value, but got -1 I recognized that against my expectation it stores the value -1. I expected the value 1.
Why is this so, should'nt it store the value 1?
This is not problem that a affects my coding negatively, But more an understanding issue, I have.
