com.sun.javafx.iio.common.RoughScaler Maven / Gradle / Ivy
/*
* Copyright (c) 2009, 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.sun.javafx.iio.common;
import java.nio.ByteBuffer;
public class RoughScaler implements PushbroomScaler {
protected int numBands; // number of bands
protected int destWidth; // destination width
protected int destHeight; // destination height
protected double scaleY;
protected ByteBuffer destBuf; // destination image buffer
protected int[] colPositions; // source column positions (non-smooth only)
protected int sourceLine; // current scanline in the source
protected int nextSourceLine; // next source line which generates a non-smooth output
protected int destLine; // current scanline in the destination
/**
* Instantiates a new RoughScaler object.
*
* @param sourceWidth The source image width
* @param sourceHeight The source image height
* @param numBands The number of components per pixel in the images
* @param destWidth The destination image width
* @param destHeight The destination image height
* @throws IllegalArgumentException if any of the parameters is non-positive.
*/
public RoughScaler(int sourceWidth, int sourceHeight, int numBands,
int destWidth, int destHeight) {
if (sourceWidth <= 0 || sourceHeight <= 0 || numBands <= 0 ||
destWidth <= 0 || destHeight <= 0) {
throw new IllegalArgumentException();
}
// save parameters to instance variables
this.numBands = numBands;
this.destWidth = destWidth;
this.destHeight = destHeight;
// allocate the destination
this.destBuf = ByteBuffer.wrap(new byte[destHeight * destWidth * numBands]);
// calculate the destination-to-source scale factors
double scaleX = (double) sourceWidth / (double) destWidth;
this.scaleY = (double) sourceHeight / (double) destHeight;
this.colPositions = new int[destWidth];
for (int i = 0; i < destWidth; i++) {
int pos = (int) ((i + 0.5) * scaleX);
colPositions[i] = pos * numBands;
}
// initialize line numbers to track source and destination lines
this.sourceLine = 0;
this.destLine = 0;
// find nearest source line
this.nextSourceLine = (int) (0.5 * scaleY);
}
/**
* Retrieves the destination buffer.
*
* @return The destination buffer.
*/
public ByteBuffer getDestination() {
return this.destBuf;
}
/**
* Push one scanline of source pixels into the scaling engine. A nearest
* neighbor interpolation algorithm is used.
*
* @param scanline One scanline of source data.
* @param off The offset into the buffer.
* @throws IllegalArgumentException if off < 0.
* @return Whether the destination image is complete.
*/
public boolean putSourceScanline(byte[] scanline, int off) {
if (off < 0) {
throw new IllegalArgumentException("off < 0!");
}
if (destLine < destHeight) {
if (sourceLine == nextSourceLine) {
assert destBuf.hasArray() : "destBuf.hasArray() == false => destBuf is direct";
byte[] dest = destBuf.array();
int destOffset = destLine * destWidth * numBands;
int doff = destOffset;
for (int i = 0; i < destWidth; i++) {
int sourceOffset = off + this.colPositions[i];
for (int j = 0; j < numBands; j++) {
dest[doff++] = scanline[sourceOffset + j];
}
}
while ((int) ((++destLine + 0.5) * scaleY) == sourceLine)
{
System.arraycopy(dest, destOffset, dest, doff, destWidth * numBands);
doff += destWidth * numBands;
}
nextSourceLine = (int) ((destLine + 0.5) * scaleY);
}
++sourceLine;
}
return destLine == destHeight;
}
}