/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @author Igor V. Stolyarov
* @version $Revision$
*/
package java.awt.image;
/**
* The RGBImageFilter class represents a filter which modifies pixels of an
* image in the default RGB ColorModel.
*
* @since Android 1.0
*/
public abstract class RGBImageFilter extends ImageFilter {
/**
* The original model is the ColorModel to be replaced by the new model when
* substituteColorModel is called.
*/
protected ColorModel origmodel;
/**
* The new model is the ColorModel with which to replace the original model
* when substituteColorModel is called.
*/
protected ColorModel newmodel;
/**
* The canFilterIndexColorModel indicates if it is acceptable to apply the
* color filtering of the filterRGB method to the color table entries of an
* IndexColorModel object.
*/
protected boolean canFilterIndexColorModel;
/**
* Instantiates a new RGBImageFilter.
*/
public RGBImageFilter() {
}
/**
* Filters an IndexColorModel object by calling filterRGB function for each
* entry of IndexColorModel.
*
* @param icm
* the IndexColorModel to be filtered.
* @return the IndexColorModel.
*/
public IndexColorModel filterIndexColorModel(IndexColorModel icm) {
int transferType = icm.getTransferType();
int bits = icm.getPixelSize();
int mapSize = icm.getMapSize();
int colorMap[] = new int[mapSize];
int filteredColorMap[] = new int[mapSize];
icm.getRGBs(colorMap);
int trans = -1;
boolean hasAlpha = false;
for (int i = 0; i < mapSize; i++) {
filteredColorMap[i] = filterRGB(-1, -1, colorMap[i]);
int alpha = filteredColorMap[i] >>> 24;
if (alpha != 0xff) {
if (!hasAlpha) {
hasAlpha = true;
}
if (alpha == 0 && trans < 0) {
trans = i;
}
}
}
return new IndexColorModel(bits, mapSize, filteredColorMap, 0, hasAlpha, trans,
transferType);
}
/**
* Replaces the original color model and the new one.
*
* @param oldcm
* the old ColorModel.
* @param newcm
* the new ColorModel.
*/
public void substituteColorModel(ColorModel oldcm, ColorModel newcm) {
origmodel = oldcm;
newmodel = newcm;
}
@Override
public void setColorModel(ColorModel model) {
if (model instanceof IndexColorModel && canFilterIndexColorModel) {
IndexColorModel icm = (IndexColorModel)model;
ColorModel filteredModel = filterIndexColorModel(icm);
substituteColorModel(model, filteredModel);
consumer.setColorModel(filteredModel);
} else {
consumer.setColorModel(ColorModel.getRGBdefault());
}
}
@Override
public void setPixels(int x, int y, int w, int h, ColorModel model, int[] pixels, int off,
int scansize) {
if (model == null || model == origmodel) {
consumer.setPixels(x, y, w, h, newmodel, pixels, off, scansize);
} else {
int rgbPixels[] = new int[w];
for (int sy = y, pixelsOff = off; sy < y + h; sy++, pixelsOff += scansize) {
for (int sx = x, idx = 0; sx < x + w; sx++, idx++) {
rgbPixels[idx] = model.getRGB(pixels[pixelsOff + idx]);
}
filterRGBPixels(x, sy, w, 1, rgbPixels, 0, w);
}
}
}
@Override
public void setPixels(int x, int y, int w, int h, ColorModel model, byte[] pixels, int off,
int scansize) {
if (model == null || model == origmodel) {
consumer.setPixels(x, y, w, h, newmodel, pixels, off, scansize);
} else {
int rgbPixels[] = new int[w];
for (int sy = y, pixelsOff = off; sy < y + h; sy++, pixelsOff += scansize) {
for (int sx = x, idx = 0; sx < x + w; sx++, idx++) {
rgbPixels[idx] = model.getRGB(pixels[pixelsOff + idx] & 0xff);
}
filterRGBPixels(x, sy, w, 1, rgbPixels, 0, w);
}
}
}
/**
* Filters a region of pixels in the default RGB ColorModel by calling the
* filterRGB method for them.
*
* @param x
* the X coordinate of region.
* @param y
* the Y coordinate of region.
* @param w
* the width of region.
* @param h
* the height of region.
* @param pixels
* the pixels array.
* @param off
* the offset of array.
* @param scansize
* the distance between rows of pixels in the array.
*/
public void filterRGBPixels(int x, int y, int w, int h, int[] pixels, int off, int scansize) {
for (int sy = y, lineOff = off; sy < y + h; sy++, lineOff += scansize) {
for (int sx = x, idx = 0; sx < x + w; sx++, idx++) {
pixels[lineOff + idx] = filterRGB(sx, sy, pixels[lineOff + idx]);
}
}
consumer.setPixels(x, y, w, h, ColorModel.getRGBdefault(), pixels, off, scansize);
}
/**
* Converts a single input pixel in the default RGB ColorModel to a single
* output pixel.
*
* @param x
* the X pixel's coordinate.
* @param y
* the Y pixel's coordinate.
* @param rgb
* a pixel in the default RGB color model.
* @return a filtered pixel in the default RGB color model.
*/
public abstract int filterRGB(int x, int y, int rgb);
}