1 /* TexturePaintContext.java -- PaintContext impl for TexturePaint 2 Copyright (C) 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 19 02110-1301 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 gnu.java.awt.java2d; 40 41 import java.awt.AWTError; 42 import java.awt.PaintContext; 43 import java.awt.Rectangle; 44 import java.awt.TexturePaint; 45 import java.awt.geom.AffineTransform; 46 import java.awt.geom.NoninvertibleTransformException; 47 import java.awt.geom.Rectangle2D; 48 import java.awt.image.BufferedImage; 49 import java.awt.image.ColorModel; 50 import java.awt.image.Raster; 51 import java.awt.image.WritableRaster; 52 53 /** 54 * A {@link PaintContext} implementation for {@link TexturePaint}, done in 55 * pure Java. 56 * 57 * @author Roman Kennke (kennke@aicas.com) 58 */ 59 public class TexturePaintContext 60 implements PaintContext 61 { 62 63 /** 64 * The TexturePaint object. 65 */ 66 private BufferedImage image; 67 68 /** 69 * The Raster that holds the texture. 70 */ 71 private WritableRaster paintRaster; 72 73 /** 74 * The transform from userspace into device space. 75 */ 76 private AffineTransform transform; 77 78 /** 79 * Creates a new TexturePaintContext for the specified TexturePaint object. 80 * This initializes the Raster which is returned by 81 * {@link #getRaster(int, int, int, int)}. 82 * 83 * @param t the texture paint object 84 * @param db the bounds of the target raster in device space 85 * @param ub the bounds of the target raster in user space 86 * @param xform the transformation from user space to device space 87 */ TexturePaintContext(TexturePaint t, Rectangle db, Rectangle2D ub, AffineTransform xform)88 public TexturePaintContext(TexturePaint t, Rectangle db, 89 Rectangle2D ub, AffineTransform xform) 90 { 91 image = t.getImage(); 92 93 try 94 { 95 // Prepare transform for mapping from device space into image space. 96 // In order to achieve this we take the transform for userspace-> 97 // devicespace, append the correct scale and translation according 98 // to the anchor (which gives us the image->userspace->devicespace 99 // transform), and invert that (which gives use the device->user->image 100 // transform). 101 Rectangle2D anchor = t.getAnchorRect(); 102 BufferedImage image = t.getImage(); 103 double scaleX = anchor.getWidth() / image.getWidth(); 104 double scaleY = anchor.getHeight() / image.getHeight(); 105 transform = (AffineTransform) xform.clone(); 106 transform.scale(scaleX, scaleY); 107 transform.translate(-anchor.getMinX(), -anchor.getMinY()); 108 transform = transform.createInverse(); 109 } 110 catch (NoninvertibleTransformException ex) 111 { 112 AWTError err = 113 new AWTError("Unexpected NoninvertibleTransformException"); 114 err.initCause(ex); 115 throw err; 116 } 117 } 118 119 /** 120 * Disposes the PaintContext. Nothing is to do here, since we don't use 121 * any native resources in that implementation. 122 */ dispose()123 public void dispose() 124 { 125 // Nothing to do here. 126 } 127 128 /** 129 * Returns the color model of this PaintContext. This implementation returnes 130 * the color model used by the BufferedImage in the TexturePaint object, 131 * this avoids costly color model transformations (at least at this point). 132 * 133 * @return the color model of this PaintContext 134 */ getColorModel()135 public ColorModel getColorModel() 136 { 137 return image.getColorModel(); 138 } 139 140 /** 141 * Returns the Raster that is used for painting. 142 * 143 * @param x1 the x location of the raster inside the user bounds of this paint 144 * context 145 * @param y1 the y location of the raster inside the user bounds of this paint 146 * context 147 * @param w the width 148 * @param h the height 149 * 150 * @return the Raster that is used for painting 151 * 152 */ getRaster(int x1, int y1, int w, int h)153 public Raster getRaster(int x1, int y1, int w, int h) 154 { 155 ensureRasterSize(w, h); 156 int x2 = x1 + w; 157 int y2 = y1 + h; 158 float[] src = new float[2]; 159 float[] dest = new float[2]; 160 Raster source = image.getData(); 161 int minX = source.getMinX(); 162 int width = source.getWidth(); 163 int minY = source.getMinY(); 164 int height = source.getHeight(); 165 Object pixel = null; 166 for (int y = y1; y < y2; y++) 167 { 168 for (int x = x1; x < x2; x++) 169 { 170 // Transform the coordinates from device space into image space. 171 src[0] = x; 172 src[1] = y; 173 transform.transform(src, 0, dest, 0, 1); 174 int dx = (int) dest[0]; 175 int dy = (int) dest[1]; 176 177 // The modulo operation gives us the replication effect. 178 dx = ((dx - minX) % width) + minX; 179 dy = ((dy - minY) % height) + minY; 180 181 // Handle possible negative values (replicating above the top-left) 182 if (dx < 0) 183 dx += width; 184 if (dy < 0) 185 dy += height; 186 187 // Copy the pixel. 188 pixel = source.getDataElements(dx, dy, pixel); 189 paintRaster.setDataElements(x - x1, y - y1, pixel); 190 } 191 } 192 return paintRaster; 193 } 194 195 /** 196 * Ensures that the target raster exists and has at least the specified 197 * size. 198 * 199 * @param w the requested target width 200 * @param h the requested target height 201 */ ensureRasterSize(int w, int h)202 private void ensureRasterSize(int w, int h) 203 { 204 if (paintRaster == null || paintRaster.getWidth() < w 205 || paintRaster.getHeight() < h) 206 { 207 Raster s = image.getData(); 208 paintRaster = s.createCompatibleWritableRaster(w, h); 209 } 210 } 211 } 212