package org.limewire.ui.swing.util;
/*
* $Id: GraphicsUtilities.java,v 1.11 2009/06/08 19:52:44 dsullivan Exp $
*
* Dual-licensed under LGPL (Sun and Romain Guy) and BSD (Romain Guy).
*
* Copyright 2005 Sun Microsystems, Inc., 4150 Network Circle,
* Santa Clara, California 95054, U.S.A. All rights reserved.
*
* Copyright (c) 2006 Romain Guy <romain.guy@mac.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;
import java.awt.GraphicsConfiguration;
import java.awt.Transparency;
import java.awt.Graphics;
import java.awt.GraphicsEnvironment;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
/**
* <p><code>GraphicsUtilities</code> contains a set of tools to perform
* common graphics operations easily. These operations are divided into
* several themes, listed below.</p>
*
* <h2>Compatible Images</h2>
*
* <p>Compatible images can, and should, be used to increase drawing
* performance. This class provides a number of methods to load compatible
* images directly from files or to convert existing images to compatibles
* images.</p>
*
* <h2>Creating Thumbnails</h2>
*
* <p>This class provides a number of methods to easily scale down images.
* Some of these methods offer a trade-off between speed and result quality and
* shouuld be used all the time. They also offer the advantage of producing
* compatible images, thus automatically resulting into better runtime
* performance.</p>
*
* <p>All these methodes are both faster than
* {@link java.awt.Image#getScaledInstance(int, int, int)} and produce
* better-looking results than the various <code>drawImage()</code> methods
* in {@link java.awt.Graphics}, which can be used for image scaling.</p>
* <h2>Image Manipulation</h2>
*
* <p>This class provides two methods to get and set pixels in a buffered image.
* These methods try to avoid unmanaging the image in order to keep good
* performance.</p>
*
* @author Romain Guy <romain.guy@mac.com>
* @author rbair
*/
public class GraphicsUtilities {
private GraphicsUtilities() {
}
// Returns the graphics configuration for the primary screen
private static GraphicsConfiguration getGraphicsConfiguration() {
return GraphicsEnvironment.getLocalGraphicsEnvironment().
getDefaultScreenDevice().getDefaultConfiguration();
}
private static boolean isHeadless() {
return GraphicsEnvironment.isHeadless();
}
/**
* <p>Returns a new <code>BufferedImage</code> using the same color model
* as the image passed as a parameter. The returned image is only compatible
* with the image passed as a parameter. This does not mean the returned
* image is compatible with the hardware.</p>
*
* @param image the reference image from which the color model of the new
* image is obtained
* @return a new <code>BufferedImage</code>, compatible with the color model
* of <code>image</code>
*/
public static BufferedImage createColorModelCompatibleImage(BufferedImage image) {
ColorModel cm = image.getColorModel();
return new BufferedImage(cm,
cm.createCompatibleWritableRaster(image.getWidth(),
image.getHeight()),
cm.isAlphaPremultiplied(), null);
}
/**
* <p>Returns a new compatible image with the same width, height and
* transparency as the image specified as a parameter. That is, the
* returned BufferedImage will be compatible with the graphics hardware.
* If this method is called in a headless environment, then
* the returned BufferedImage will be compatible with the source
* image.</p>
*
* @see java.awt.Transparency
* @see #createCompatibleImage(int, int)
* @see #createCompatibleImage(java.awt.image.BufferedImage, int, int)
* @see #createCompatibleTranslucentImage(int, int)
* @see #loadCompatibleImage(java.net.URL)
* @see #toCompatibleImage(java.awt.image.BufferedImage)
* @param image the reference image from which the dimension and the
* transparency of the new image are obtained
* @return a new compatible <code>BufferedImage</code> with the same
* dimension and transparency as <code>image</code>
*/
public static BufferedImage createCompatibleImage(BufferedImage image) {
return createCompatibleImage(image, image.getWidth(), image.getHeight());
}
/**
* <p>Returns a new compatible image of the specified width and height, and
* the same transparency setting as the image specified as a parameter.
* That is, the returned <code>BufferedImage</code> is compatible with
* the graphics hardware. If the method is called in a headless
* environment, then the returned BufferedImage will be compatible with
* the source image.</p>
*
* @see java.awt.Transparency
* @see #createCompatibleImage(java.awt.image.BufferedImage)
* @see #createCompatibleImage(int, int)
* @see #createCompatibleTranslucentImage(int, int)
* @see #loadCompatibleImage(java.net.URL)
* @see #toCompatibleImage(java.awt.image.BufferedImage)
* @param width the width of the new image
* @param height the height of the new image
* @param image the reference image from which the transparency of the new
* image is obtained
* @return a new compatible <code>BufferedImage</code> with the same
* transparency as <code>image</code> and the specified dimension
*/
public static BufferedImage createCompatibleImage(BufferedImage image,
int width, int height) {
return isHeadless() ?
new BufferedImage(width, height, image.getType()) :
getGraphicsConfiguration().createCompatibleImage(width, height,
image.getTransparency());
}
/**
* <p>Returns a new opaque compatible image of the specified width and
* height. That is, the returned <code>BufferedImage</code> is compatible with
* the graphics hardware. If the method is called in a headless
* environment, then the returned BufferedImage will be compatible with
* the source image.</p>
*
* @see #createCompatibleImage(java.awt.image.BufferedImage)
* @see #createCompatibleImage(java.awt.image.BufferedImage, int, int)
* @see #createCompatibleTranslucentImage(int, int)
* @see #loadCompatibleImage(java.net.URL)
* @see #toCompatibleImage(java.awt.image.BufferedImage)
* @param width the width of the new image
* @param height the height of the new image
* @return a new opaque compatible <code>BufferedImage</code> of the
* specified width and height
*/
public static BufferedImage createCompatibleImage(int width, int height) {
return isHeadless() ?
new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB) :
getGraphicsConfiguration().createCompatibleImage(width, height);
}
/**
* <p>Returns a new translucent compatible image of the specified width and
* height. That is, the returned <code>BufferedImage</code> is compatible with
* the graphics hardware. If the method is called in a headless
* environment, then the returned BufferedImage will be compatible with
* the source image.</p>
*
* @see #createCompatibleImage(java.awt.image.BufferedImage)
* @see #createCompatibleImage(java.awt.image.BufferedImage, int, int)
* @see #createCompatibleImage(int, int)
* @see #loadCompatibleImage(java.net.URL)
* @see #toCompatibleImage(java.awt.image.BufferedImage)
* @param width the width of the new image
* @param height the height of the new image
* @return a new translucent compatible <code>BufferedImage</code> of the
* specified width and height
*/
public static BufferedImage createCompatibleTranslucentImage(int width,
int height) {
return isHeadless() ?
new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB) :
getGraphicsConfiguration().createCompatibleImage(width, height,
Transparency.TRANSLUCENT);
}
/**
* <p>Returns a new compatible image from a URL. The image is loaded from the
* specified location and then turned, if necessary into a compatible
* image.</p>
*
* @see #createCompatibleImage(java.awt.image.BufferedImage)
* @see #createCompatibleImage(java.awt.image.BufferedImage, int, int)
* @see #createCompatibleImage(int, int)
* @see #createCompatibleTranslucentImage(int, int)
* @see #toCompatibleImage(java.awt.image.BufferedImage)
* @param resource the URL of the picture to load as a compatible image
* @return a new translucent compatible <code>BufferedImage</code> of the
* specified width and height
* @throws java.io.IOException if the image cannot be read or loaded
*/
public static BufferedImage loadCompatibleImage(URL resource)
throws IOException {
BufferedImage image = ImageIO.read(resource);
return toCompatibleImage(image);
}
/**
* <p>Return a new compatible image that contains a copy of the specified
* image. This method ensures an image is compatible with the hardware,
* and therefore optimized for fast blitting operations.</p>
*
* <p>If the method is called in a headless environment, then the returned
* <code>BufferedImage</code> will be the source image.</p>
*
* @see #createCompatibleImage(java.awt.image.BufferedImage)
* @see #createCompatibleImage(java.awt.image.BufferedImage, int, int)
* @see #createCompatibleImage(int, int)
* @see #createCompatibleTranslucentImage(int, int)
* @see #loadCompatibleImage(java.net.URL)
* @param image the image to copy into a new compatible image
* @return a new compatible copy, with the
* same width and height and transparency and content, of <code>image</code>
*/
public static BufferedImage toCompatibleImage(BufferedImage image) {
if (isHeadless()) {
return image;
}
if (image.getColorModel().equals(
getGraphicsConfiguration().getColorModel())) {
return image;
}
BufferedImage compatibleImage =
getGraphicsConfiguration().createCompatibleImage(
image.getWidth(), image.getHeight(),
image.getTransparency());
Graphics g = compatibleImage.getGraphics();
g.drawImage(image, 0, 0, null);
g.dispose();
return compatibleImage;
}
/**
* <p>Returns a thumbnail of a source image. <code>newSize</code> defines
* the length of the longest dimension of the thumbnail. The other
* dimension is then computed according to the dimensions ratio of the
* original picture.</p>
* <p>This method favors speed over quality. When the new size is less than
* half the longest dimension of the source image,
* {@link #createThumbnail(BufferedImage, int)} or
* {@link #createThumbnail(BufferedImage, int, int)} should be used instead
* to ensure the quality of the result without sacrificing too much
* performance.</p>
*
* @see #createThumbnailFast(java.awt.image.BufferedImage, int, int)
* @see #createThumbnail(java.awt.image.BufferedImage, int)
* @see #createThumbnail(java.awt.image.BufferedImage, int, int)
* @param image the source image
* @param newSize the length of the largest dimension of the thumbnail
* @return a new compatible <code>BufferedImage</code> containing a
* thumbnail of <code>image</code>
* @throws IllegalArgumentException if <code>newSize</code> is larger than
* the largest dimension of <code>image</code> or <= 0
*/
public static BufferedImage createThumbnailFast(BufferedImage image,
int newSize) {
float ratio;
int width = image.getWidth();
int height = image.getHeight();
if (width > height) {
if (newSize >= width) {
throw new IllegalArgumentException("newSize must be lower than" +
" the image width");
} else if (newSize <= 0) {
throw new IllegalArgumentException("newSize must" +
" be greater than 0");
}
ratio = (float) width / (float) height;
width = newSize;
height = (int) (newSize / ratio);
} else {
if (newSize >= height) {
throw new IllegalArgumentException("newSize must be lower than" +
" the image height");
} else if (newSize <= 0) {
throw new IllegalArgumentException("newSize must" +
" be greater than 0");
}
ratio = (float) height / (float) width;
height = newSize;
width = (int) (newSize / ratio);
}
BufferedImage temp = createCompatibleImage(image, width, height);
Graphics2D g2 = temp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2.drawImage(image, 0, 0, temp.getWidth(), temp.getHeight(), null);
g2.dispose();
return temp;
}
/**
* <p>Returns a thumbnail of a source image.</p>
* <p>This method favors speed over quality. When the new size is less than
* half the longest dimension of the source image,
* {@link #createThumbnail(BufferedImage, int)} or
* {@link #createThumbnail(BufferedImage, int, int)} should be used instead
* to ensure the quality of the result without sacrificing too much
* performance.</p>
*
* @see #createThumbnailFast(java.awt.image.BufferedImage, int)
* @see #createThumbnail(java.awt.image.BufferedImage, int)
* @see #createThumbnail(java.awt.image.BufferedImage, int, int)
* @param image the source image
* @param newWidth the width of the thumbnail
* @param newHeight the height of the thumbnail
* @return a new compatible <code>BufferedImage</code> containing a
* thumbnail of <code>image</code>
* @throws IllegalArgumentException if <code>newWidth</code> is larger than
* the width of <code>image</code> or if code>newHeight</code> is larger
* than the height of <code>image</code> or if one of the dimensions
* is <= 0
*/
public static BufferedImage createThumbnailFast(BufferedImage image,
int newWidth, int newHeight) {
if (newWidth >= image.getWidth() ||
newHeight >= image.getHeight()) {
throw new IllegalArgumentException("newWidth and newHeight cannot" +
" be greater than the image" +
" dimensions");
} else if (newWidth <= 0 || newHeight <= 0) {
throw new IllegalArgumentException("newWidth and newHeight must" +
" be greater than 0");
}
BufferedImage temp = createCompatibleImage(image, newWidth, newHeight);
Graphics2D g2 = temp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2.drawImage(image, 0, 0, temp.getWidth(), temp.getHeight(), null);
g2.dispose();
return temp;
}
/**
* Creates a thumbnail of the source image. This scales the image in a single pass, resulting in
* a low quality thumbnail but the aspect ratio of the image is still preserved.
*
* @param image image to create a thumbnail of
* @param maxTargetWidth max width the thumbnail can be
* @param maxTargetHeight max height the thumbnail ca
*/
public static BufferedImage createRatioPreservedThumbnailFast(BufferedImage image, int maxWidth, int maxHeight) {
int width = image.getWidth();
int height = image.getHeight();
boolean isWidthGreater = width > height;
float ratioWH = (float) width / (float) height;
float ratioHW = (float) height / (float) width;
int newWidth;
int newHeight;
if (isWidthGreater) {
newWidth = maxWidth;
newHeight = (int) (newWidth / ratioWH);
} else {
newHeight = maxHeight;
newWidth = (int) (newHeight / ratioHW);
}
BufferedImage temp = createCompatibleImage(image, newWidth, newHeight);
Graphics2D g2 = temp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BICUBIC);
g2.drawImage(image, 0, 0, temp.getWidth(), temp.getHeight(), null);
g2.dispose();
return temp;
}
/**
* Returns a thumbnail of the source image. This preserves the aspect ratio of the image. All images will
* always be scaled to fit within the targetWidth and the taretHeight of the image.
*
* @param image image to create a thumbnail of
* @param maxTargetWidth max width the thumbnail can be
* @param maxTargetHeight max height the thumbnail can be
*/
@SuppressWarnings("null")
public static BufferedImage createRatioPreservedThumbnail(BufferedImage image, int maxTargetWidth, int maxTargetHeight) {
int width = image.getWidth();
int height = image.getHeight();
boolean isTranslucent = image.getTransparency() != Transparency.OPAQUE;
if (maxTargetWidth <= 0 || maxTargetHeight <= 0) {
throw new IllegalArgumentException("newSize must" +
" be greater than 0");
}
float ratioWH = (float) width / (float) height;
float ratioHW = (float) height / (float) width;
BufferedImage thumb = image;
BufferedImage temp = null;
Graphics2D g2 = null;
int previousWidth = width;
int previousHeight = height;
try {
do {
if (width > maxTargetWidth) {
width /= 2;
if (width < maxTargetWidth) {
width = maxTargetWidth;
}
height = (int) (width / ratioWH);
} else if (height > maxTargetHeight) {
height /= 2;
if (height < maxTargetHeight) {
height = maxTargetHeight;
}
width = (int) (height / ratioHW);
}
if (temp == null || isTranslucent) {
try {
temp = createCompatibleImage(image, width, height);
} catch(Throwable e) {
temp = new BufferedImage(width, height, image.getType());
}
if(g2 != null)
g2.dispose();
g2 = temp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
}
g2.drawImage(thumb, 0, 0, width, height,
0, 0, previousWidth, previousHeight, null);
previousWidth = width;
previousHeight = height;
thumb = temp;
} while ( (width > maxTargetWidth) || (height > maxTargetHeight));
} finally {
temp.flush();
g2.dispose();
image.flush();
}
if (width != thumb.getWidth() || height != thumb.getHeight()) {
try {
temp = createCompatibleImage(thumb, width, height);
g2 = temp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2.drawImage(thumb, 0, 0, width, height, 0, 0, width, height, null);
thumb = temp;
} finally {
g2.dispose();
temp.flush();
}
}
return thumb;
}
/**
* <p>Returns a thumbnail of a source image. <code>newSize</code> defines
* the length of the longest dimension of the thumbnail. The other
* dimension is then computed according to the dimensions ratio of the
* original picture.</p>
* <p>This method offers a good trade-off between speed and quality.
* The result looks better than
* {@link #createThumbnailFast(java.awt.image.BufferedImage, int)} when
* the new size is less than half the longest dimension of the source
* image, yet the rendering speed is almost similar.</p>
*
* @see #createThumbnailFast(java.awt.image.BufferedImage, int, int)
* @see #createThumbnailFast(java.awt.image.BufferedImage, int)
* @see #createThumbnail(java.awt.image.BufferedImage, int, int)
* @param image the source image
* @param newSize the length of the largest dimension of the thumbnail
* @return a new compatible <code>BufferedImage</code> containing a
* thumbnail of <code>image</code>
* @throws IllegalArgumentException if <code>newSize</code> is larger than
* the largest dimension of <code>image</code> or <= 0
*/
@SuppressWarnings("null")
public static BufferedImage createThumbnail(BufferedImage image, int newSize) {
int width = image.getWidth();
int height = image.getHeight();
boolean isTranslucent = image.getTransparency() != Transparency.OPAQUE;
boolean isWidthGreater = width > height;
if (isWidthGreater) {
if (newSize >= width) {
throw new IllegalArgumentException("newSize must be lower than" +
" the image width");
}
} else if (newSize >= height) {
throw new IllegalArgumentException("newSize must be lower than" +
" the image height");
}
if (newSize <= 0) {
throw new IllegalArgumentException("newSize must" +
" be greater than 0");
}
float ratioWH = (float) width / (float) height;
float ratioHW = (float) height / (float) width;
BufferedImage thumb = image;
BufferedImage temp = null;
Graphics2D g2 = null;
int previousWidth = width;
int previousHeight = height;
do {
if (isWidthGreater) {
width /= 2;
if (width < newSize) {
width = newSize;
}
height = (int) (width / ratioWH);
} else {
height /= 2;
if (height < newSize) {
height = newSize;
}
width = (int) (height / ratioHW);
}
if (temp == null || isTranslucent) {
temp = createCompatibleImage(image, width, height);
if(g2 != null)
g2.dispose();
g2 = temp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
}
g2.drawImage(thumb, 0, 0, width, height,
0, 0, previousWidth, previousHeight, null);
previousWidth = width;
previousHeight = height;
thumb = temp;
} while (newSize != (isWidthGreater ? width : height));
g2.dispose();
if (width != thumb.getWidth() || height != thumb.getHeight()) {
temp = createCompatibleImage(thumb, width, height);
g2 = temp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2.drawImage(thumb, 0, 0, width, height, null);
g2.dispose();
thumb = temp;
}
return thumb;
}
/**
* <p>Returns a thumbnail of a source image.</p>
* <p>This method offers a good trade-off between speed and quality.
* The result looks better than
* {@link #createThumbnailFast(java.awt.image.BufferedImage, int)} when
* the new size is less than half the longest dimension of the source
* image, yet the rendering speed is almost similar.</p>
*
* @see #createThumbnailFast(java.awt.image.BufferedImage, int)
* @see #createThumbnailFast(java.awt.image.BufferedImage, int, int)
* @see #createThumbnail(java.awt.image.BufferedImage, int)
* @param image the source image
* @param newWidth the width of the thumbnail
* @param newHeight the height of the thumbnail
* @return a new compatible <code>BufferedImage</code> containing a
* thumbnail of <code>image</code>
* @throws IllegalArgumentException if <code>newWidth</code> is larger than
* the width of <code>image</code> or if code>newHeight</code> is larger
* than the height of <code>image or if one the dimensions is not > 0</code>
*/
@SuppressWarnings("null")
public static BufferedImage createThumbnail(BufferedImage image,
int newWidth, int newHeight) {
int width = image.getWidth();
int height = image.getHeight();
boolean isTranslucent = image.getTransparency() != Transparency.OPAQUE;
if (newWidth >= width || newHeight >= height) {
throw new IllegalArgumentException("newWidth and newHeight cannot" +
" be greater than the image" +
" dimensions");
} else if (newWidth <= 0 || newHeight <= 0) {
throw new IllegalArgumentException("newWidth and newHeight must" +
" be greater than 0");
}
BufferedImage thumb = image;
BufferedImage temp = null;
Graphics2D g2 = null;
int previousWidth = width;
int previousHeight = height;
do {
if (width > newWidth) {
width /= 2;
if (width < newWidth) {
width = newWidth;
}
}
if (height > newHeight) {
height /= 2;
if (height < newHeight) {
height = newHeight;
}
}
if (temp == null || isTranslucent) {
temp = createCompatibleImage(image, width, height);
if(g2 != null)
g2.dispose();
g2 = temp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
}
g2.drawImage(thumb, 0, 0, width, height,
0, 0, previousWidth, previousHeight, null);
previousWidth = width;
previousHeight = height;
thumb = temp;
} while (width != newWidth || height != newHeight);
g2.dispose();
if (width != thumb.getWidth() || height != thumb.getHeight()) {
temp = createCompatibleImage(thumb, width, height);
g2 = temp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2.drawImage(thumb, 0, 0, width, height, null);
g2.dispose();
thumb = temp;
}
return thumb;
}
/**
* <p>Returns an array of pixels, stored as integers, from a
* <code>BufferedImage</code>. The pixels are grabbed from a rectangular
* area defined by a location and two dimensions. Calling this method on
* an image of type different from <code>BufferedImage.TYPE_INT_ARGB</code>
* and <code>BufferedImage.TYPE_INT_RGB</code> will unmanage the image.</p>
*
* @param img the source image
* @param x the x location at which to start grabbing pixels
* @param y the y location at which to start grabbing pixels
* @param w the width of the rectangle of pixels to grab
* @param h the height of the rectangle of pixels to grab
* @param pixels a pre-allocated array of pixels of size w*h; can be null
* @return <code>pixels</code> if non-null, a new array of integers
* otherwise
* @throws IllegalArgumentException is <code>pixels</code> is non-null and
* of length < w*h
*/
public static int[] getPixels(BufferedImage img,
int x, int y, int w, int h, int[] pixels) {
if (w == 0 || h == 0) {
return new int[0];
}
if (pixels == null) {
pixels = new int[w * h];
} else if (pixels.length < w * h) {
throw new IllegalArgumentException("pixels array must have a length" +
" >= w*h");
}
int imageType = img.getType();
if (imageType == BufferedImage.TYPE_INT_ARGB ||
imageType == BufferedImage.TYPE_INT_RGB) {
Raster raster = img.getRaster();
return (int[]) raster.getDataElements(x, y, w, h, pixels);
}
// Unmanages the image
return img.getRGB(x, y, w, h, pixels, 0, w);
}
/**
* <p>Writes a rectangular area of pixels in the destination
* <code>BufferedImage</code>. Calling this method on
* an image of type different from <code>BufferedImage.TYPE_INT_ARGB</code>
* and <code>BufferedImage.TYPE_INT_RGB</code> will unmanage the image.</p>
*
* @param img the destination image
* @param x the x location at which to start storing pixels
* @param y the y location at which to start storing pixels
* @param w the width of the rectangle of pixels to store
* @param h the height of the rectangle of pixels to store
* @param pixels an array of pixels, stored as integers
* @throws IllegalArgumentException is <code>pixels</code> is non-null and
* of length < w*h
*/
public static void setPixels(BufferedImage img,
int x, int y, int w, int h, int[] pixels) {
if (pixels == null || w == 0 || h == 0) {
return;
} else if (pixels.length < w * h) {
throw new IllegalArgumentException("pixels array must have a length" +
" >= w*h");
}
int imageType = img.getType();
if (imageType == BufferedImage.TYPE_INT_ARGB ||
imageType == BufferedImage.TYPE_INT_RGB) {
WritableRaster raster = img.getRaster();
raster.setDataElements(x, y, w, h, pixels);
} else {
// Unmanages the image
img.setRGB(x, y, w, h, pixels, 0, w);
}
}
}