package tutorial;

import com.nativelibs4java.opencl.*;

import java.io.IOException;

import java.nio.DoubleBuffer;

public class DFT2 {

final CLQueue queue;

final CLContext context;

final DiscreteFourierTransformProgram program;

public DFT2(CLQueue queue) throws IOException, CLBuildException {

this.queue = queue;

this.context = queue.getContext();

this.program = new DiscreteFourierTransformProgram(context);

}

public synchronized DoubleBuffer dft(DoubleBuffer in, boolean forward) throws CLBuildException {

assert in.capacity() % 2 == 0;

int length = in.capacity() / 2;

CLDoubleBuffer inBuf = context.createDoubleBuffer(CLMem.Usage.Input, in, true); // true = copy

CLDoubleBuffer outBuf = context.createDoubleBuffer(CLMem.Usage.Output, length * 2);

// The following call is type-safe, thanks to the JavaCL Maven generator :

// (if the OpenCL function signature changes, the generated Java definition will be updated and compilation will fail)

CLEvent dftEvt = program.dft(queue, inBuf, outBuf, length, forward ? 1 : -1, new int[]{length}, null);

return outBuf.read(queue, dftEvt);

}

public double[] dft(double[] complexValues, boolean forward) throws CLBuildException {

DoubleBuffer outBuffer = dft(DoubleBuffer.wrap(complexValues), forward);

double[] out = new double[complexValues.length];

outBuffer.get(out);

return out;

}

}