J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package java.awt; |
| 27 | |
| 28 | import java.awt.image.Raster; |
| 29 | import sun.awt.image.IntegerComponentRaster; |
| 30 | import java.awt.image.ColorModel; |
| 31 | import java.awt.image.DirectColorModel; |
| 32 | import java.awt.geom.Point2D; |
| 33 | import java.awt.geom.AffineTransform; |
| 34 | import java.awt.geom.NoninvertibleTransformException; |
| 35 | import java.lang.ref.WeakReference; |
| 36 | |
| 37 | class GradientPaintContext implements PaintContext { |
| 38 | static ColorModel xrgbmodel = |
| 39 | new DirectColorModel(24, 0x00ff0000, 0x0000ff00, 0x000000ff); |
| 40 | static ColorModel xbgrmodel = |
| 41 | new DirectColorModel(24, 0x000000ff, 0x0000ff00, 0x00ff0000); |
| 42 | |
| 43 | static ColorModel cachedModel; |
| 44 | static WeakReference cached; |
| 45 | |
| 46 | static synchronized Raster getCachedRaster(ColorModel cm, int w, int h) { |
| 47 | if (cm == cachedModel) { |
| 48 | if (cached != null) { |
| 49 | Raster ras = (Raster) cached.get(); |
| 50 | if (ras != null && |
| 51 | ras.getWidth() >= w && |
| 52 | ras.getHeight() >= h) |
| 53 | { |
| 54 | cached = null; |
| 55 | return ras; |
| 56 | } |
| 57 | } |
| 58 | } |
| 59 | return cm.createCompatibleWritableRaster(w, h); |
| 60 | } |
| 61 | |
| 62 | static synchronized void putCachedRaster(ColorModel cm, Raster ras) { |
| 63 | if (cached != null) { |
| 64 | Raster cras = (Raster) cached.get(); |
| 65 | if (cras != null) { |
| 66 | int cw = cras.getWidth(); |
| 67 | int ch = cras.getHeight(); |
| 68 | int iw = ras.getWidth(); |
| 69 | int ih = ras.getHeight(); |
| 70 | if (cw >= iw && ch >= ih) { |
| 71 | return; |
| 72 | } |
| 73 | if (cw * ch >= iw * ih) { |
| 74 | return; |
| 75 | } |
| 76 | } |
| 77 | } |
| 78 | cachedModel = cm; |
| 79 | cached = new WeakReference(ras); |
| 80 | } |
| 81 | |
| 82 | double x1; |
| 83 | double y1; |
| 84 | double dx; |
| 85 | double dy; |
| 86 | boolean cyclic; |
| 87 | int interp[]; |
| 88 | Raster saved; |
| 89 | ColorModel model; |
| 90 | |
| 91 | public GradientPaintContext(ColorModel cm, |
| 92 | Point2D p1, Point2D p2, AffineTransform xform, |
| 93 | Color c1, Color c2, boolean cyclic) { |
| 94 | // First calculate the distance moved in user space when |
| 95 | // we move a single unit along the X & Y axes in device space. |
| 96 | Point2D xvec = new Point2D.Double(1, 0); |
| 97 | Point2D yvec = new Point2D.Double(0, 1); |
| 98 | try { |
| 99 | AffineTransform inverse = xform.createInverse(); |
| 100 | inverse.deltaTransform(xvec, xvec); |
| 101 | inverse.deltaTransform(yvec, yvec); |
| 102 | } catch (NoninvertibleTransformException e) { |
| 103 | xvec.setLocation(0, 0); |
| 104 | yvec.setLocation(0, 0); |
| 105 | } |
| 106 | |
| 107 | // Now calculate the (square of the) user space distance |
| 108 | // between the anchor points. This value equals: |
| 109 | // (UserVec . UserVec) |
| 110 | double udx = p2.getX() - p1.getX(); |
| 111 | double udy = p2.getY() - p1.getY(); |
| 112 | double ulenSq = udx * udx + udy * udy; |
| 113 | |
| 114 | if (ulenSq <= Double.MIN_VALUE) { |
| 115 | dx = 0; |
| 116 | dy = 0; |
| 117 | } else { |
| 118 | // Now calculate the proportional distance moved along the |
| 119 | // vector from p1 to p2 when we move a unit along X & Y in |
| 120 | // device space. |
| 121 | // |
| 122 | // The length of the projection of the Device Axis Vector is |
| 123 | // its dot product with the Unit User Vector: |
| 124 | // (DevAxisVec . (UserVec / Len(UserVec)) |
| 125 | // |
| 126 | // The "proportional" length is that length divided again |
| 127 | // by the length of the User Vector: |
| 128 | // (DevAxisVec . (UserVec / Len(UserVec))) / Len(UserVec) |
| 129 | // which simplifies to: |
| 130 | // ((DevAxisVec . UserVec) / Len(UserVec)) / Len(UserVec) |
| 131 | // which simplifies to: |
| 132 | // (DevAxisVec . UserVec) / LenSquared(UserVec) |
| 133 | dx = (xvec.getX() * udx + xvec.getY() * udy) / ulenSq; |
| 134 | dy = (yvec.getX() * udx + yvec.getY() * udy) / ulenSq; |
| 135 | |
| 136 | if (cyclic) { |
| 137 | dx = dx % 1.0; |
| 138 | dy = dy % 1.0; |
| 139 | } else { |
| 140 | // We are acyclic |
| 141 | if (dx < 0) { |
| 142 | // If we are using the acyclic form below, we need |
| 143 | // dx to be non-negative for simplicity of scanning |
| 144 | // across the scan lines for the transition points. |
| 145 | // To ensure that constraint, we negate the dx/dy |
| 146 | // values and swap the points and colors. |
| 147 | Point2D p = p1; p1 = p2; p2 = p; |
| 148 | Color c = c1; c1 = c2; c2 = c; |
| 149 | dx = -dx; |
| 150 | dy = -dy; |
| 151 | } |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | Point2D dp1 = xform.transform(p1, null); |
| 156 | this.x1 = dp1.getX(); |
| 157 | this.y1 = dp1.getY(); |
| 158 | |
| 159 | this.cyclic = cyclic; |
| 160 | int rgb1 = c1.getRGB(); |
| 161 | int rgb2 = c2.getRGB(); |
| 162 | int a1 = (rgb1 >> 24) & 0xff; |
| 163 | int r1 = (rgb1 >> 16) & 0xff; |
| 164 | int g1 = (rgb1 >> 8) & 0xff; |
| 165 | int b1 = (rgb1 ) & 0xff; |
| 166 | int da = ((rgb2 >> 24) & 0xff) - a1; |
| 167 | int dr = ((rgb2 >> 16) & 0xff) - r1; |
| 168 | int dg = ((rgb2 >> 8) & 0xff) - g1; |
| 169 | int db = ((rgb2 ) & 0xff) - b1; |
| 170 | if (a1 == 0xff && da == 0) { |
| 171 | model = xrgbmodel; |
| 172 | if (cm instanceof DirectColorModel) { |
| 173 | DirectColorModel dcm = (DirectColorModel) cm; |
| 174 | int tmp = dcm.getAlphaMask(); |
| 175 | if ((tmp == 0 || tmp == 0xff) && |
| 176 | dcm.getRedMask() == 0xff && |
| 177 | dcm.getGreenMask() == 0xff00 && |
| 178 | dcm.getBlueMask() == 0xff0000) |
| 179 | { |
| 180 | model = xbgrmodel; |
| 181 | tmp = r1; r1 = b1; b1 = tmp; |
| 182 | tmp = dr; dr = db; db = tmp; |
| 183 | } |
| 184 | } |
| 185 | } else { |
| 186 | model = ColorModel.getRGBdefault(); |
| 187 | } |
| 188 | interp = new int[cyclic ? 513 : 257]; |
| 189 | for (int i = 0; i <= 256; i++) { |
| 190 | float rel = i / 256.0f; |
| 191 | int rgb = |
| 192 | (((int) (a1 + da * rel)) << 24) | |
| 193 | (((int) (r1 + dr * rel)) << 16) | |
| 194 | (((int) (g1 + dg * rel)) << 8) | |
| 195 | (((int) (b1 + db * rel)) ); |
| 196 | interp[i] = rgb; |
| 197 | if (cyclic) { |
| 198 | interp[512 - i] = rgb; |
| 199 | } |
| 200 | } |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | * Release the resources allocated for the operation. |
| 205 | */ |
| 206 | public void dispose() { |
| 207 | if (saved != null) { |
| 208 | putCachedRaster(model, saved); |
| 209 | saved = null; |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | /** |
| 214 | * Return the ColorModel of the output. |
| 215 | */ |
| 216 | public ColorModel getColorModel() { |
| 217 | return model; |
| 218 | } |
| 219 | |
| 220 | /** |
| 221 | * Return a Raster containing the colors generated for the graphics |
| 222 | * operation. |
| 223 | * @param x,y,w,h The area in device space for which colors are |
| 224 | * generated. |
| 225 | */ |
| 226 | public Raster getRaster(int x, int y, int w, int h) { |
| 227 | double rowrel = (x - x1) * dx + (y - y1) * dy; |
| 228 | |
| 229 | Raster rast = saved; |
| 230 | if (rast == null || rast.getWidth() < w || rast.getHeight() < h) { |
| 231 | rast = getCachedRaster(model, w, h); |
| 232 | saved = rast; |
| 233 | } |
| 234 | IntegerComponentRaster irast = (IntegerComponentRaster) rast; |
| 235 | int off = irast.getDataOffset(0); |
| 236 | int adjust = irast.getScanlineStride() - w; |
| 237 | int[] pixels = irast.getDataStorage(); |
| 238 | |
| 239 | if (cyclic) { |
| 240 | cycleFillRaster(pixels, off, adjust, w, h, rowrel, dx, dy); |
| 241 | } else { |
| 242 | clipFillRaster(pixels, off, adjust, w, h, rowrel, dx, dy); |
| 243 | } |
| 244 | |
| 245 | irast.markDirty(); |
| 246 | |
| 247 | return rast; |
| 248 | } |
| 249 | |
| 250 | void cycleFillRaster(int[] pixels, int off, int adjust, int w, int h, |
| 251 | double rowrel, double dx, double dy) { |
| 252 | rowrel = rowrel % 2.0; |
| 253 | int irowrel = ((int) (rowrel * (1 << 30))) << 1; |
| 254 | int idx = (int) (-dx * (1 << 31)); |
| 255 | int idy = (int) (-dy * (1 << 31)); |
| 256 | while (--h >= 0) { |
| 257 | int icolrel = irowrel; |
| 258 | for (int j = w; j > 0; j--) { |
| 259 | pixels[off++] = interp[icolrel >>> 23]; |
| 260 | icolrel += idx; |
| 261 | } |
| 262 | |
| 263 | off += adjust; |
| 264 | irowrel += idy; |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | void clipFillRaster(int[] pixels, int off, int adjust, int w, int h, |
| 269 | double rowrel, double dx, double dy) { |
| 270 | while (--h >= 0) { |
| 271 | double colrel = rowrel; |
| 272 | int j = w; |
| 273 | if (colrel <= 0.0) { |
| 274 | int rgb = interp[0]; |
| 275 | do { |
| 276 | pixels[off++] = rgb; |
| 277 | colrel += dx; |
| 278 | } while (--j > 0 && colrel <= 0.0); |
| 279 | } |
| 280 | while (colrel < 1.0 && --j >= 0) { |
| 281 | pixels[off++] = interp[(int) (colrel * 256)]; |
| 282 | colrel += dx; |
| 283 | } |
| 284 | if (j > 0) { |
| 285 | int rgb = interp[256]; |
| 286 | do { |
| 287 | pixels[off++] = rgb; |
| 288 | } while (--j > 0); |
| 289 | } |
| 290 | |
| 291 | off += adjust; |
| 292 | rowrel += dy; |
| 293 | } |
| 294 | } |
| 295 | } |