1 /* RGBImageFilter.java -- Java class for filtering Pixels by RGB values
2    Copyright (C) 1999 Free Software Foundation, Inc.
3 
4 This file is part of GNU Classpath.
5 
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10 
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 General Public License for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING.  If not, write to the
18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19 02111-1307 USA.
20 
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library.  Thus, the terms and
23 conditions of the GNU General Public License cover the whole
24 combination.
25 
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module.  An independent module is a module which is not derived from
33 or based on this library.  If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so.  If you do not wish to do so, delete this
36 exception statement from your version. */
37 
38 
39 package java.awt.image;
40 
41 /**
42  * A filter designed to filter images in the default RGBColorModel regardless of
43  * the ImageProducer's ColorModel.
44  *
45  * @author Mark Benvenuto <mcb54@columbia.edu>
46  */
47 public abstract class RGBImageFilter extends ImageFilter
48 {
49     protected ColorModel origmodel = ColorModel.getRGBdefault();
50 
51     protected ColorModel newmodel;
52 
53     /**
54        Specifies whether to apply the filter to the index entries of the
55        IndexColorModel. Subclasses should set this to true if the filter
56        does not depend on the pixel's coordinate.
57      */
58     protected boolean canFilterIndexColorModel = false;
59 
60     /**
61        Construct new RGBImageFilter.
62      */
RGBImageFilter()63     public RGBImageFilter()
64     {
65     }
66 
67     /**
68      * Sets the ColorModel used to filter with. If the specified ColorModel is IndexColorModel
69      * and canFilterIndexColorModel is true, we subsitute the ColorModel for a filtered one
70      * here and in setPixels whenever the original one appears. Otherwise overrides the default
71      * ColorModel of ImageProducer and specifies the default RGBColorModel
72      *
73      * @param model the color model to be used most often by setPixels
74      * @see ColorModel */
setColorModel(ColorModel model)75     public void setColorModel(ColorModel model)
76     {
77 	origmodel = model;
78 	newmodel = model;
79 
80 	if( ( model instanceof IndexColorModel) && canFilterIndexColorModel  ) {
81 		newmodel = filterIndexColorModel( (IndexColorModel) model );
82 	    }
83     }
84 
85     /**
86        Registers a new ColorModel to subsitute for the old ColorModel when
87        setPixels encounters the a pixel with the old ColorModel. The pixel
88        remains unchanged except for a new ColorModel.
89 
90        @param oldcm the old ColorModel
91        @param newcm the new ColorModel
92      */
substituteColorModel(ColorModel oldcm, ColorModel newcm)93     public void substituteColorModel(ColorModel oldcm,
94 				     ColorModel newcm)
95     {
96 	origmodel = oldcm;
97 	newmodel = newcm;
98     }
99 
100     /**
101        Filters an IndexColorModel through the filterRGB function. Uses
102        coordinates of -1 to indicate its filtering an index and not a pixel.
103 
104        @param icm an IndexColorModel to filter
105      */
filterIndexColorModel(IndexColorModel icm)106     public IndexColorModel filterIndexColorModel(IndexColorModel icm)
107     {
108 	int len = icm.getMapSize(), rgb;
109 	byte reds[] = new byte[len], greens[] = new byte[len], blues[] = new byte[len], alphas[]  = new byte[len];
110 
111 	icm.getAlphas( alphas );
112 	icm.getReds( reds );
113 	icm.getGreens( greens );
114 	icm.getBlues( blues );
115 
116 	for( int i = 0; i < len; i++ )
117 	    {
118 		rgb = filterRGB( -1, -1, makeColor ( alphas[i], reds[i], greens[i], blues[i] ) );
119 		alphas[i] = (byte)(( 0xff000000 & rgb ) >> 24);
120 		reds[i] = (byte)(( 0xff0000 & rgb ) >> 16);
121 		greens[i] = (byte)(( 0xff00 & rgb ) >> 8);
122 		blues[i] = (byte)(0xff & rgb);
123 	    }
124 	return new IndexColorModel( icm.getPixelSize(), len, reds, greens, blues, alphas );
125     }
126 
makeColor( byte a, byte r, byte g, byte b )127     private int makeColor( byte a, byte r, byte g, byte b )
128     {
129 	return ( 0xff000000 & (a << 24) | 0xff0000 & (r << 16) | 0xff00 & (b << 8) | 0xff & g );
130     }
131 
132     /**
133        This functions filters a set of RGB pixels through filterRGB.
134 
135        @param x the x coordinate of the rectangle
136        @param y the y coordinate of the rectangle
137        @param w the width of the rectangle
138        @param h the height of the rectangle
139        @param model the <code>ColorModel</code> used to translate the pixels
140        @param pixels the array of pixel values
141        @param offset the index of the first pixels in the <code>pixels</code> array
142        @param scansize the width to use in extracting pixels from the <code>pixels</code> array
143     */
filterRGBPixels(int x, int y, int w, int h, int[] pixels, int off, int scansize)144     public void filterRGBPixels(int x,
145 				int y,
146 				int w,
147 				int h,
148 				int[] pixels,
149 				int off,
150 				int scansize)
151     {
152 	int xp, yp;
153 
154 	for( xp = x; xp < ( x + w); xp++ )
155 	    for( yp = y; yp < (y + h); yp++ )
156 		 pixels[ off + yp * scansize + xp ] = filterRGB( xp, yp, pixels[ off + yp * scansize + xp ] );
157     }
158 
159 
160     /**
161      * If the ColorModel is the same ColorModel which as already converted
162      * then it converts it the converted ColorModel. Otherwise it passes the
163      * array of pixels through filterRGBpixels.
164      *
165      * @param x the x coordinate of the rectangle
166      * @param y the y coordinate of the rectangle
167      * @param w the width of the rectangle
168      * @param h the height of the rectangle
169      * @param model the <code>ColorModel</code> used to translate the pixels
170      * @param pixels the array of pixel values
171      * @param offset the index of the first pixels in the <code>pixels</code> array
172      * @param scansize the width to use in extracting pixels from the <code>pixels</code> array
173      */
setPixels(int x, int y, int w, int h, ColorModel model, byte[] pixels, int offset, int scansize)174     public void setPixels(int x, int y, int w, int h,
175 	   ColorModel model, byte[] pixels, int offset, int scansize)
176     {
177 	if( model == origmodel ) {
178 	    consumer.setPixels(x, y, w, h, newmodel, pixels, offset, scansize);
179 	} else {
180 	    //FIXME
181 	    //convert to proper CM
182 	    int pixelsi[] = new int[ pixels.length / 4 ];
183 	    filterRGBPixels( x, y, w, h, pixelsi, offset, scansize );
184 	}
185     }
186 
187     /**
188      * This function delivers a rectangle of pixels where any
189      * pixel(m,n) is stored in the array as an <code>int</code> at
190      * index (n * scansize + m + offset).
191      *
192      * @param x the x coordinate of the rectangle
193      * @param y the y coordinate of the rectangle
194      * @param w the width of the rectangle
195      * @param h the height of the rectangle
196      * @param model the <code>ColorModel</code> used to translate the pixels
197      * @param pixels the array of pixel values
198      * @param offset the index of the first pixels in the <code>pixels</code> array
199      * @param scansize the width to use in extracting pixels from the <code>pixels</code> array
200      */
setPixels(int x, int y, int w, int h, ColorModel model, int[] pixels, int offset, int scansize)201     public void setPixels(int x, int y, int w, int h,
202            ColorModel model, int[] pixels, int offset, int scansize)
203     {
204 	if( model == origmodel ) {
205 	    consumer.setPixels(x, y, w, h, newmodel, pixels, offset, scansize);
206 	} else {
207 	    convertColorModelToDefault( x, y, w, h, model, pixels, offset, scansize );
208 	    filterRGBPixels( x, y, w, h, pixels, offset, scansize );
209 	}
210     }
211 
convertColorModelToDefault( int x, int y, int w, int h, ColorModel model, int pixels[], int offset, int scansize)212     private void convertColorModelToDefault( int x, int y, int w, int h,
213 	    ColorModel model, int pixels[], int offset, int scansize)
214 	{
215 	int xp, yp;
216 
217 	for( xp = x; xp < ( x + w); xp++ )
218 	    for( yp = y; yp < (y + h); yp++ )
219 		 pixels[ offset + yp * scansize + xp ] =  makeColorbyDefaultCM( pixels[ offset + yp * scansize + xp ] );
220 
221 	}
makeColorbyDefaultCM( int rgb )222     private int makeColorbyDefaultCM( int rgb )
223 	{
224 	    return makeColor( origmodel.getRed( rgb ), origmodel.getGreen( rgb ), origmodel.getGreen( rgb ), origmodel.getBlue( rgb ) );
225 	}
226 
227 
makeColor( int a, int r, int g, int b )228     private int makeColor( int a, int r, int g, int b )
229     {
230 	return (int)( 0xff000000 & (a << 24) | 0xff0000 & (r << 16) | 0xff00 & (b << 8) | 0xff & g );
231     }
232 
233 
234     /**
235        Filters a single pixel from the default ColorModel.
236 
237        @param x x-coordinate
238        @param y y-coordinate
239        @param rgb color
240      */
filterRGB(int x, int y, int rgb)241     public abstract int filterRGB(int x,
242 				  int y,
243 				  int rgb);
244 }
245