Albert Strasheim wrote:
Unless I'm mistaken, ByteBuffer#asFloatBuffer() returns a FloatBuffer
that throws UnsupportedOperationException when you call array(), so
there's no way for me to get a float[] from this kind of buffer without
copying.
There's no way to get a float[] without copying.
The JVM doesn't appear to support mapping a region of native memory to
primitive arrays - it all has to go through a DirectByteBuffer, and be
accessed via ByteBuffer.get(), ByteBuffer.asFloatBuffer() and friends.
Thus, it would be useful if I could pass these kinds of buffers directly
to JNA.
The best I can do is make something like this work:
interface Foo extends Library {
void some_function(FloatBuffer fb);
}
which would be equivalent to:
interface Foo extends Library {
void some_function(float[] fb);
}
That _should_ pass the array directly to JNI - depending on whether the
VM supports/can pin the array. If not it will copy to/from a native
buffer and pass that on. If your native code depends on the address of
the array not changing, that will break, but otherwise it should be fine.
12 messages in net.java.dev.jna.usersRe: [jna-users] Buffer arguments as p...
