/*
* Copyright 2011, Zettabyte Storage LLC
*
* This file is part of Vash.
*
* Vash is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Vash is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with Vash. If not, see <http://www.gnu.org/licenses/>.
*/
package vash.operation;
import vash.ImageParameters;
import vash.Plane;
import vash.Seed;
import vash.value.Bounded;
import vash.value.Wrapping;
public class Sinc extends OperationNode {
private final static double MIN_FREQ = 1.0f * (float)-Math.PI;
private final static double MAX_FREQ = 1.0f * (float)Math.PI;
private final static double MIN_PHASE = 1.0f * (float)-Math.PI;
private final static double MAX_PHASE = 1.0f * (float)Math.PI;
private final Bounded frequency;
private final Wrapping phase;
private Sinc(Bounded frequency, Wrapping phase, OperationNode child) {
super(2, 1);
assert(frequency.hasBounds(MIN_FREQ, MAX_FREQ));
assert(phase.hasBounds(MIN_PHASE, MAX_PHASE));
_values[0] = this.frequency = frequency;
_values[1] = this.phase = phase;
_children[0] = child;
}
public Sinc(double freq, double phase, OperationNode child) {
this(new Bounded(freq, MIN_FREQ, MAX_FREQ), new Wrapping(phase, MIN_PHASE, MAX_PHASE), child);
}
public Sinc(Seed s) {
this(new Bounded(s, MIN_FREQ, MAX_FREQ), new Wrapping(s, MIN_PHASE, MAX_PHASE), null);
}
@Override
public OperationNode clone() {
return new Sinc(this.frequency.clone(), this.phase.clone(), _children[0].clone());
}
@Override
public Plane compute(ImageParameters ip) {
float freq = (float)this.frequency.getV();
float phase = (float)this.phase.getV();
Plane A = _children[0].compute(ip);
Plane out = ip.getPlane();
for(int j = 0; j < ip.getH(); j++ ) {
for(int i = 0; i < ip.getW(); i++) {
float denom = A.data[i][j] * freq + phase;
if(denom == 0.0f)
out.data[i][j] = 1.0f;
else
out.data[i][j] = OperationNode.clampf((float)(Math.sin(denom) / denom), -1.0f, 1.0f);
}
}
ip.putPlane(A);
return out;
}
}