I have written a .obj parser in java to modelize 3D objects on iPhone. I would like to export the data as a binary file, which must be as small as possible. I have plenty of indices that would fit a unsigned short, but they are represented as int in java.
I would like to use the ByteBuffer class to do the conversion just before writing the data in a file. I suppose I will开发者_Go百科 have to manipulate bytes before pushing them into the ByteBuffer but I have no idea how to do so.
Thank you in advance if you can help me.
In Java, an unsigned short can be represented as a char
. Just cast the int to char and use putChar()
on the ByteBuffer.
myBuffer.putChar((char) my16BitInt);
short toUint16(int i)
{
return (short) i;
}
int toUint32(short s)
{
return s & 0xFFFF;
}
You can extract single bytes from your integers with
int i;
byte b1 = i & 0xFF;
byte b2 = (i >> 8) & 0xFF;
Use http://download.oracle.com/javase/6/docs/api/java/io/DataOutputStream.html
dos.writeShort(value & 0xFFFF);
精彩评论