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| 1 | /* | ||
| 2 | * Copyright (c) 2006, 2007, Oracle and/or its affiliates. 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. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | |||
| 26 | package java.awt; | ||
| 27 | |||
| 28 | import java.awt.MultipleGradientPaint.CycleMethod; | ||
| 29 | import java.awt.MultipleGradientPaint.ColorSpaceType; | ||
| 30 | import java.awt.color.ColorSpace; | ||
| 31 | import java.awt.geom.AffineTransform; | ||
| 32 | import java.awt.geom.NoninvertibleTransformException; | ||
| 33 | import java.awt.geom.Rectangle2D; | ||
| 34 | import java.awt.image.ColorModel; | ||
| 35 | import java.awt.image.DataBuffer; | ||
| 36 | import java.awt.image.DataBufferInt; | ||
| 37 | import java.awt.image.DirectColorModel; | ||
| 38 | import java.awt.image.Raster; | ||
| 39 | import java.awt.image.SinglePixelPackedSampleModel; | ||
| 40 | import java.awt.image.WritableRaster; | ||
| 41 | import java.lang.ref.SoftReference; | ||
| 42 | import java.lang.ref.WeakReference; | ||
| 43 | import java.util.Arrays; | ||
| 44 | |||
| 45 | /** | ||
| 46 | * This is the superclass for all PaintContexts which use a multiple color | ||
| 47 | * gradient to fill in their raster. It provides the actual color | ||
| 48 | * interpolation functionality. Subclasses only have to deal with using | ||
| 49 | * the gradient to fill pixels in a raster. | ||
| 50 | * | ||
| 51 | * @author Nicholas Talian, Vincent Hardy, Jim Graham, Jerry Evans | ||
| 52 | */ | ||
| 53 | abstract class MultipleGradientPaintContext implements PaintContext { | ||
| 54 | |||
| 55 | /** | ||
| 56 | * The PaintContext's ColorModel. This is ARGB if colors are not all | ||
| 57 | * opaque, otherwise it is RGB. | ||
| 58 | */ | ||
| 59 | protected ColorModel model; | ||
| 60 | |||
| 61 | /** Color model used if gradient colors are all opaque. */ | ||
| 62 | private static ColorModel xrgbmodel = | ||
| 63 | new DirectColorModel(24, 0x00ff0000, 0x0000ff00, 0x000000ff); | ||
| 64 | |||
| 65 | /** The cached ColorModel. */ | ||
| 66 | protected static ColorModel cachedModel; | ||
| 67 | |||
| 68 | /** The cached raster, which is reusable among instances. */ | ||
| 69 | protected static WeakReference<Raster> cached; | ||
| 70 | |||
| 71 | /** Raster is reused whenever possible. */ | ||
| 72 | protected Raster saved; | ||
| 73 | |||
| 74 | /** The method to use when painting out of the gradient bounds. */ | ||
| 75 | protected CycleMethod cycleMethod; | ||
| 76 | |||
| 77 | /** The ColorSpace in which to perform the interpolation */ | ||
| 78 | protected ColorSpaceType colorSpace; | ||
| 79 | |||
| 80 | /** Elements of the inverse transform matrix. */ | ||
| 81 | protected float a00, a01, a10, a11, a02, a12; | ||
| 82 | |||
| 83 | /** | ||
| 84 | * This boolean specifies wether we are in simple lookup mode, where an | ||
| 85 | * input value between 0 and 1 may be used to directly index into a single | ||
| 86 | * array of gradient colors. If this boolean value is false, then we have | ||
| 87 | * to use a 2-step process where we have to determine which gradient array | ||
| 88 | * we fall into, then determine the index into that array. | ||
| 89 | */ | ||
| 90 | protected boolean isSimpleLookup; | ||
| 91 | |||
| 92 | /** | ||
| 93 | * Size of gradients array for scaling the 0-1 index when looking up | ||
| 94 | * colors the fast way. | ||
| 95 | */ | ||
| 96 | protected int fastGradientArraySize; | ||
| 97 | |||
| 98 | /** | ||
| 99 | * Array which contains the interpolated color values for each interval, | ||
| 100 | * used by calculateSingleArrayGradient(). It is protected for possible | ||
| 101 | * direct access by subclasses. | ||
| 102 | */ | ||
| 103 | protected int[] gradient; | ||
| 104 | |||
| 105 | /** | ||
| 106 | * Array of gradient arrays, one array for each interval. Used by | ||
| 107 | * calculateMultipleArrayGradient(). | ||
| 108 | */ | ||
| 109 | private int[][] gradients; | ||
| 110 | |||
| 111 | /** Normalized intervals array. */ | ||
| 112 | private float[] normalizedIntervals; | ||
| 113 | |||
| 114 | /** Fractions array. */ | ||
| 115 | private float[] fractions; | ||
| 116 | |||
| 117 | /** Used to determine if gradient colors are all opaque. */ | ||
| 118 | private int transparencyTest; | ||
| 119 | |||
| 120 | /** Color space conversion lookup tables. */ | ||
| 121 | private static final int SRGBtoLinearRGB[] = new int[256]; | ||
| 122 | private static final int LinearRGBtoSRGB[] = new int[256]; | ||
| 123 | |||
| 124 | static { | ||
| 125 | // build the tables | ||
| 126 | for (int k = 0; k < 256; k++) { | ||
| 127 | SRGBtoLinearRGB[k] = convertSRGBtoLinearRGB(k); | ||
| 128 | LinearRGBtoSRGB[k] = convertLinearRGBtoSRGB(k); | ||
| 129 | } | ||
| 130 | } | ||
| 131 | |||
| 132 | /** | ||
| 133 | * Constant number of max colors between any 2 arbitrary colors. | ||
| 134 | * Used for creating and indexing gradients arrays. | ||
| 135 | */ | ||
| 136 | protected static final int GRADIENT_SIZE = 256; | ||
| 137 | protected static final int GRADIENT_SIZE_INDEX = GRADIENT_SIZE -1; | ||
| 138 | |||
| 139 | /** | ||
| 140 | * Maximum length of the fast single-array. If the estimated array size | ||
| 141 | * is greater than this, switch over to the slow lookup method. | ||
| 142 | * No particular reason for choosing this number, but it seems to provide | ||
| 143 | * satisfactory performance for the common case (fast lookup). | ||
| 144 | */ | ||
| 145 | private static final int MAX_GRADIENT_ARRAY_SIZE = 5000; | ||
| 146 | |||
| 147 | /** | ||
| 148 | * Constructor for MultipleGradientPaintContext superclass. | ||
| 149 | */ | ||
| 150 | protected MultipleGradientPaintContext(MultipleGradientPaint mgp, | ||
| 151 | ColorModel cm, | ||
| 152 | Rectangle deviceBounds, | ||
| 153 | Rectangle2D userBounds, | ||
| 154 | AffineTransform t, | ||
| 155 | RenderingHints hints, | ||
| 156 | float[] fractions, | ||
| 157 | Color[] colors, | ||
| 158 | CycleMethod cycleMethod, | ||
| 159 | ColorSpaceType colorSpace) | ||
| 160 | { | ||
| 161 | if (deviceBounds == null) { | ||
| 162 | throw new NullPointerException("Device bounds cannot be null"); | ||
| 163 | } | ||
| 164 | |||
| 165 | if (userBounds == null) { | ||
| 166 | throw new NullPointerException("User bounds cannot be null"); | ||
| 167 | } | ||
| 168 | |||
| 169 | if (t == null) { | ||
| 170 | throw new NullPointerException("Transform cannot be null"); | ||
| 171 | } | ||
| 172 | |||
| 173 | if (hints == null) { | ||
| 174 | throw new NullPointerException("RenderingHints cannot be null"); | ||
| 175 | } | ||
| 176 | |||
| 177 | // The inverse transform is needed to go from device to user space. | ||
| 178 | // Get all the components of the inverse transform matrix. | ||
| 179 | AffineTransform tInv; | ||
| 180 | try { | ||
| 181 | // the following assumes that the caller has copied the incoming | ||
| 182 | // transform and is not concerned about it being modified | ||
| 183 | t.invert(); | ||
| 184 | tInv = t; | ||
| 185 | } catch (NoninvertibleTransformException e) { | ||
| 186 | // just use identity transform in this case; better to show | ||
| 187 | // (incorrect) results than to throw an exception and/or no-op | ||
| 188 | tInv = new AffineTransform(); | ||
| 189 | } | ||
| 190 | double m[] = new double[6]; | ||
| 191 | tInv.getMatrix(m); | ||
| 192 | a00 = (float)m[0]; | ||
| 193 | a10 = (float)m[1]; | ||
| 194 | a01 = (float)m[2]; | ||
| 195 | a11 = (float)m[3]; | ||
| 196 | a02 = (float)m[4]; | ||
| 197 | a12 = (float)m[5]; | ||
| 198 | |||
| 199 | // copy some flags | ||
| 200 | this.cycleMethod = cycleMethod; | ||
| 201 | this.colorSpace = colorSpace; | ||
| 202 | |||
| 203 | // we can avoid copying this array since we do not modify its values | ||
| 204 | this.fractions = fractions; | ||
| 205 | |||
| 206 | // note that only one of these values can ever be non-null (we either | ||
| 207 | // store the fast gradient array or the slow one, but never both | ||
| 208 | // at the same time) | ||
| 209 | int[] gradient = | ||
| 210 | (mgp.gradient != null) ? mgp.gradient.get() : null; | ||
| 211 | int[][] gradients = | ||
| 212 | (mgp.gradients != null) ? mgp.gradients.get() : null; | ||
| 213 | |||
| 214 | if (gradient == null && gradients == null) { | ||
| 215 | // we need to (re)create the appropriate values | ||
| 216 | calculateLookupData(colors); | ||
| 217 | |||
| 218 | // now cache the calculated values in the | ||
| 219 | // MultipleGradientPaint instance for future use | ||
| 220 | mgp.model = this.model; | ||
| 221 | mgp.normalizedIntervals = this.normalizedIntervals; | ||
| 222 | mgp.isSimpleLookup = this.isSimpleLookup; | ||
| 223 | if (isSimpleLookup) { | ||
| 224 | // only cache the fast array | ||
| 225 | mgp.fastGradientArraySize = this.fastGradientArraySize; | ||
| 226 | mgp.gradient = new SoftReference<int[]>(this.gradient); | ||
| 227 | } else { | ||
| 228 | // only cache the slow array | ||
| 229 | mgp.gradients = new SoftReference<int[][]>(this.gradients); | ||
| 230 | } | ||
| 231 | } else { | ||
| 232 | // use the values cached in the MultipleGradientPaint instance | ||
| 233 | this.model = mgp.model; | ||
| 234 | this.normalizedIntervals = mgp.normalizedIntervals; | ||
| 235 | this.isSimpleLookup = mgp.isSimpleLookup; | ||
| 236 | this.gradient = gradient; | ||
| 237 | this.fastGradientArraySize = mgp.fastGradientArraySize; | ||
| 238 | this.gradients = gradients; | ||
| 239 | } | ||
| 240 | } | ||
| 241 | |||
| 242 | /** | ||
| 243 | * This function is the meat of this class. It calculates an array of | ||
| 244 | * gradient colors based on an array of fractions and color values at | ||
| 245 | * those fractions. | ||
| 246 | */ | ||
| 247 | private void calculateLookupData(Color[] colors) { | ||
| 248 | Color[] normalizedColors; | ||
| 249 | if (colorSpace == ColorSpaceType.LINEAR_RGB) { | ||
| 250 | // create a new colors array | ||
| 251 | normalizedColors = new Color[colors.length]; | ||
| 252 | // convert the colors using the lookup table | ||
| 253 | for (int i = 0; i < colors.length; i++) { | ||
| 254 | int argb = colors[i].getRGB(); | ||
| 255 | int a = argb >>> 24; | ||
| 256 | int r = SRGBtoLinearRGB[(argb >> 16) & 0xff]; | ||
| 257 | int g = SRGBtoLinearRGB[(argb >> 8) & 0xff]; | ||
| 258 | int b = SRGBtoLinearRGB[(argb ) & 0xff]; | ||
| 259 | normalizedColors[i] = new Color(r, g, b, a); | ||
| 260 | } | ||
| 261 | } else { | ||
| 262 | // we can just use this array by reference since we do not | ||
| 263 | // modify its values in the case of SRGB | ||
| 264 | normalizedColors = colors; | ||
| 265 | } | ||
| 266 | |||
| 267 | // this will store the intervals (distances) between gradient stops | ||
| 268 | normalizedIntervals = new float[fractions.length-1]; | ||
| 269 | |||
| 270 | // convert from fractions into intervals | ||
| 271 | for (int i = 0; i < normalizedIntervals.length; i++) { | ||
| 272 | // interval distance is equal to the difference in positions | ||
| 273 | normalizedIntervals[i] = this.fractions[i+1] - this.fractions[i]; | ||
| 274 | } | ||
| 275 | |||
| 276 | // initialize to be fully opaque for ANDing with colors | ||
| 277 | transparencyTest = 0xff000000; | ||
| 278 | |||
| 279 | // array of interpolation arrays | ||
| 280 | gradients = new int[normalizedIntervals.length][]; | ||
| 281 | |||
| 282 | // find smallest interval | ||
| 283 | float Imin = 1; | ||
| 284 | for (int i = 0; i < normalizedIntervals.length; i++) { | ||
| 285 | Imin = (Imin > normalizedIntervals[i]) ? | ||
| 286 | normalizedIntervals[i] : Imin; | ||
| 287 | } | ||
| 288 | |||
| 289 | // Estimate the size of the entire gradients array. | ||
| 290 | // This is to prevent a tiny interval from causing the size of array | ||
| 291 | // to explode. If the estimated size is too large, break to using | ||
| 292 | // separate arrays for each interval, and using an indexing scheme at | ||
| 293 | // look-up time. | ||
| 294 | int estimatedSize = 0; | ||
| 295 | for (int i = 0; i < normalizedIntervals.length; i++) { | ||
| 296 | estimatedSize += (normalizedIntervals[i]/Imin) * GRADIENT_SIZE; | ||
| 297 | } | ||
| 298 | |||
| 299 | if (estimatedSize > MAX_GRADIENT_ARRAY_SIZE) { | ||
| 300 | // slow method | ||
| 301 | calculateMultipleArrayGradient(normalizedColors); | ||
| 302 | } else { | ||
| 303 | // fast method | ||
| 304 | calculateSingleArrayGradient(normalizedColors, Imin); | ||
| 305 | } | ||
| 306 | |||
| 307 | // use the most "economical" model | ||
| 308 | if ((transparencyTest >>> 24) == 0xff) { | ||
| 309 | model = xrgbmodel; | ||
| 310 | } else { | ||
| 311 | model = ColorModel.getRGBdefault(); | ||
| 312 | } | ||
| 313 | } | ||
| 314 | |||
| 315 | /** | ||
| 316 | * FAST LOOKUP METHOD | ||
| 317 | * | ||
| 318 | * This method calculates the gradient color values and places them in a | ||
| 319 | * single int array, gradient[]. It does this by allocating space for | ||
| 320 | * each interval based on its size relative to the smallest interval in | ||
| 321 | * the array. The smallest interval is allocated 255 interpolated values | ||
| 322 | * (the maximum number of unique in-between colors in a 24 bit color | ||
| 323 | * system), and all other intervals are allocated | ||
| 324 | * size = (255 * the ratio of their size to the smallest interval). | ||
| 325 | * | ||
| 326 | * This scheme expedites a speedy retrieval because the colors are | ||
| 327 | * distributed along the array according to their user-specified | ||
| 328 | * distribution. All that is needed is a relative index from 0 to 1. | ||
| 329 | * | ||
| 330 | * The only problem with this method is that the possibility exists for | ||
| 331 | * the array size to balloon in the case where there is a | ||
| 332 | * disproportionately small gradient interval. In this case the other | ||
| 333 | * intervals will be allocated huge space, but much of that data is | ||
| 334 | * redundant. We thus need to use the space conserving scheme below. | ||
| 335 | * | ||
| 336 | * @param Imin the size of the smallest interval | ||
| 337 | */ | ||
| 338 | private void calculateSingleArrayGradient(Color[] colors, float Imin) { | ||
| 339 | // set the flag so we know later it is a simple (fast) lookup | ||
| 340 | isSimpleLookup = true; | ||
| 341 | |||
| 342 | // 2 colors to interpolate | ||
| 343 | int rgb1, rgb2; | ||
| 344 | |||
| 345 | //the eventual size of the single array | ||
| 346 | int gradientsTot = 1; | ||
| 347 | |||
| 348 | // for every interval (transition between 2 colors) | ||
| 349 | for (int i = 0; i < gradients.length; i++) { | ||
| 350 | // create an array whose size is based on the ratio to the | ||
| 351 | // smallest interval | ||
| 352 | int nGradients = (int)((normalizedIntervals[i]/Imin)*255f); | ||
| 353 | gradientsTot += nGradients; | ||
| 354 | gradients[i] = new int[nGradients]; | ||
| 355 | |||
| 356 | // the 2 colors (keyframes) to interpolate between | ||
| 357 | rgb1 = colors[i].getRGB(); | ||
| 358 | rgb2 = colors[i+1].getRGB(); | ||
| 359 | |||
| 360 | // fill this array with the colors in between rgb1 and rgb2 | ||
| 361 | interpolate(rgb1, rgb2, gradients[i]); | ||
| 362 | |||
| 363 | // if the colors are opaque, transparency should still | ||
| 364 | // be 0xff000000 | ||
| 365 | transparencyTest &= rgb1; | ||
| 366 | transparencyTest &= rgb2; | ||
| 367 | } | ||
| 368 | |||
| 369 | // put all gradients in a single array | ||
| 370 | gradient = new int[gradientsTot]; | ||
| 371 | int curOffset = 0; | ||
| 372 | for (int i = 0; i < gradients.length; i++){ | ||
| 373 | System.arraycopy(gradients[i], 0, gradient, | ||
| 374 | curOffset, gradients[i].length); | ||
| 375 | curOffset += gradients[i].length; | ||
| 376 | } | ||
| 377 | gradient[gradient.length-1] = colors[colors.length-1].getRGB(); | ||
| 378 | |||
| 379 | // if interpolation occurred in Linear RGB space, convert the | ||
| 380 | // gradients back to sRGB using the lookup table | ||
| 381 | if (colorSpace == ColorSpaceType.LINEAR_RGB) { | ||
| 382 | for (int i = 0; i < gradient.length; i++) { | ||
| 383 | gradient[i] = convertEntireColorLinearRGBtoSRGB(gradient[i]); | ||
| 384 | } | ||
| 385 | } | ||
| 386 | |||
| 387 | fastGradientArraySize = gradient.length - 1; | ||
| 388 | } | ||
| 389 | |||
| 390 | /** | ||
| 391 | * SLOW LOOKUP METHOD | ||
| 392 | * | ||
| 393 | * This method calculates the gradient color values for each interval and | ||
| 394 | * places each into its own 255 size array. The arrays are stored in | ||
| 395 | * gradients[][]. (255 is used because this is the maximum number of | ||
| 396 | * unique colors between 2 arbitrary colors in a 24 bit color system.) | ||
| 397 | * | ||
| 398 | * This method uses the minimum amount of space (only 255 * number of | ||
| 399 | * intervals), but it aggravates the lookup procedure, because now we | ||
| 400 | * have to find out which interval to select, then calculate the index | ||
| 401 | * within that interval. This causes a significant performance hit, | ||
| 402 | * because it requires this calculation be done for every point in | ||
| 403 | * the rendering loop. | ||
| 404 | * | ||
| 405 | * For those of you who are interested, this is a classic example of the | ||
| 406 | * time-space tradeoff. | ||
| 407 | */ | ||
| 408 | private void calculateMultipleArrayGradient(Color[] colors) { | ||
| 409 | // set the flag so we know later it is a non-simple lookup | ||
| 410 | isSimpleLookup = false; | ||
| 411 | |||
| 412 | // 2 colors to interpolate | ||
| 413 | int rgb1, rgb2; | ||
| 414 | |||
| 415 | // for every interval (transition between 2 colors) | ||
| 416 | for (int i = 0; i < gradients.length; i++){ | ||
| 417 | // create an array of the maximum theoretical size for | ||
| 418 | // each interval | ||
| 419 | gradients[i] = new int[GRADIENT_SIZE]; | ||
| 420 | |||
| 421 | // get the the 2 colors | ||
| 422 | rgb1 = colors[i].getRGB(); | ||
| 423 | rgb2 = colors[i+1].getRGB(); | ||
| 424 | |||
| 425 | // fill this array with the colors in between rgb1 and rgb2 | ||
| 426 | interpolate(rgb1, rgb2, gradients[i]); | ||
| 427 | |||
| 428 | // if the colors are opaque, transparency should still | ||
| 429 | // be 0xff000000 | ||
| 430 | transparencyTest &= rgb1; | ||
| 431 | transparencyTest &= rgb2; | ||
| 432 | } | ||
| 433 | |||
| 434 | // if interpolation occurred in Linear RGB space, convert the | ||
| 435 | // gradients back to SRGB using the lookup table | ||
| 436 | if (colorSpace == ColorSpaceType.LINEAR_RGB) { | ||
| 437 | for (int j = 0; j < gradients.length; j++) { | ||
| 438 | for (int i = 0; i < gradients[j].length; i++) { | ||
| 439 | gradients[j][i] = | ||
| 440 | convertEntireColorLinearRGBtoSRGB(gradients[j][i]); | ||
| 441 | } | ||
| 442 | } | ||
| 443 | } | ||
| 444 | } | ||
| 445 | |||
| 446 | /** | ||
| 447 | * Yet another helper function. This one linearly interpolates between | ||
| 448 | * 2 colors, filling up the output array. | ||
| 449 | * | ||
| 450 | * @param rgb1 the start color | ||
| 451 | * @param rgb2 the end color | ||
| 452 | * @param output the output array of colors; must not be null | ||
| 453 | */ | ||
| 454 | private void interpolate(int rgb1, int rgb2, int[] output) { | ||
| 455 | // color components | ||
| 456 | int a1, r1, g1, b1, da, dr, dg, db; | ||
| 457 | |||
| 458 | // step between interpolated values | ||
| 459 | float stepSize = 1.0f / output.length; | ||
| 460 | |||
| 461 | // extract color components from packed integer | ||
| 462 | a1 = (rgb1 >> 24) & 0xff; | ||
| 463 | r1 = (rgb1 >> 16) & 0xff; | ||
| 464 | g1 = (rgb1 >> 8) & 0xff; | ||
| 465 | b1 = (rgb1 ) & 0xff; | ||
| 466 | |||
| 467 | // calculate the total change in alpha, red, green, blue | ||
| 468 | da = ((rgb2 >> 24) & 0xff) - a1; | ||
| 469 | dr = ((rgb2 >> 16) & 0xff) - r1; | ||
| 470 | dg = ((rgb2 >> 8) & 0xff) - g1; | ||
| 471 | db = ((rgb2 ) & 0xff) - b1; | ||
| 472 | |||
| 473 | // for each step in the interval calculate the in-between color by | ||
| 474 | // multiplying the normalized current position by the total color | ||
| 475 | // change (0.5 is added to prevent truncation round-off error) | ||
| 476 | for (int i = 0; i < output.length; i++) { | ||
| 477 | output[i] = | ||
| 478 | (((int) ((a1 + i * da * stepSize) + 0.5) << 24)) | | ||
| 479 | (((int) ((r1 + i * dr * stepSize) + 0.5) << 16)) | | ||
| 480 | (((int) ((g1 + i * dg * stepSize) + 0.5) << 8)) | | ||
| 481 | (((int) ((b1 + i * db * stepSize) + 0.5) )); | ||
| 482 | } | ||
| 483 | } | ||
| 484 | |||
| 485 | /** | ||
| 486 | * Yet another helper function. This one extracts the color components | ||
| 487 | * of an integer RGB triple, converts them from LinearRGB to SRGB, then | ||
| 488 | * recompacts them into an int. | ||
| 489 | */ | ||
| 490 | private int convertEntireColorLinearRGBtoSRGB(int rgb) { | ||
| 491 | // color components | ||
| 492 | int a1, r1, g1, b1; | ||
| 493 | |||
| 494 | // extract red, green, blue components | ||
| 495 | a1 = (rgb >> 24) & 0xff; | ||
| 496 | r1 = (rgb >> 16) & 0xff; | ||
| 497 | g1 = (rgb >> 8) & 0xff; | ||
| 498 | b1 = (rgb ) & 0xff; | ||
| 499 | |||
| 500 | // use the lookup table | ||
| 501 | r1 = LinearRGBtoSRGB[r1]; | ||
| 502 | g1 = LinearRGBtoSRGB[g1]; | ||
| 503 | b1 = LinearRGBtoSRGB[b1]; | ||
| 504 | |||
| 505 | // re-compact the components | ||
| 506 | return ((a1 << 24) | | ||
| 507 | (r1 << 16) | | ||
| 508 | (g1 << 8) | | ||
| 509 | (b1 )); | ||
| 510 | } | ||
| 511 | |||
| 512 | /** | ||
| 513 | * Helper function to index into the gradients array. This is necessary | ||
| 514 | * because each interval has an array of colors with uniform size 255. | ||
| 515 | * However, the color intervals are not necessarily of uniform length, so | ||
| 516 | * a conversion is required. | ||
| 517 | * | ||
| 518 | * @param position the unmanipulated position, which will be mapped | ||
| 519 | * into the range 0 to 1 | ||
| 520 | * @returns integer color to display | ||
| 521 | */ | ||
| 522 | protected final int indexIntoGradientsArrays(float position) { | ||
| 523 | // first, manipulate position value depending on the cycle method | ||
| 524 | if (cycleMethod == CycleMethod.NO_CYCLE) { | ||
| 525 | if (position > 1) { | ||
| 526 | // upper bound is 1 | ||
| 527 | position = 1; | ||
| 528 | } else if (position < 0) { | ||
| 529 | // lower bound is 0 | ||
| 530 | position = 0; | ||
| 531 | } | ||
| 532 | } else if (cycleMethod == CycleMethod.REPEAT) { | ||
| 533 | // get the fractional part | ||
| 534 | // (modulo behavior discards integer component) | ||
| 535 | position = position - (int)position; | ||
| 536 | |||
| 537 | //position should now be between -1 and 1 | ||
| 538 | if (position < 0) { | ||
| 539 | // force it to be in the range 0-1 | ||
| 540 | position = position + 1; | ||
| 541 | } | ||
| 542 | } else { // cycleMethod == CycleMethod.REFLECT | ||
| 543 | if (position < 0) { | ||
| 544 | // take absolute value | ||
| 545 | position = -position; | ||
| 546 | } | ||
| 547 | |||
| 548 | // get the integer part | ||
| 549 | int part = (int)position; | ||
| 550 | |||
| 551 | // get the fractional part | ||
| 552 | position = position - part; | ||
| 553 | |||
| 554 | if ((part & 1) == 1) { | ||
| 555 | // integer part is odd, get reflected color instead | ||
| 556 | position = 1 - position; | ||
| 557 | } | ||
| 558 | } | ||
| 559 | |||
| 560 | // now, get the color based on this 0-1 position... | ||
| 561 | |||
| 562 | if (isSimpleLookup) { | ||
| 563 | // easy to compute: just scale index by array size | ||
| 564 | return gradient[(int)(position * fastGradientArraySize)]; | ||
| 565 | } else { | ||
| 566 | // more complicated computation, to save space | ||
| 567 | |||
| 568 | // for all the gradient interval arrays | ||
| 569 | for (int i = 0; i < gradients.length; i++) { | ||
| 570 | if (position < fractions[i+1]) { | ||
| 571 | // this is the array we want | ||
| 572 | float delta = position - fractions[i]; | ||
| 573 | |||
| 574 | // this is the interval we want | ||
| 575 | int index = (int)((delta / normalizedIntervals[i]) | ||
| 576 | * (GRADIENT_SIZE_INDEX)); | ||
| 577 | |||
| 578 | return gradients[i][index]; | ||
| 579 | } | ||
| 580 | } | ||
| 581 | } | ||
| 582 | |||
| 583 | return gradients[gradients.length - 1][GRADIENT_SIZE_INDEX]; | ||
| 584 | } | ||
| 585 | |||
| 586 | /** | ||
| 587 | * Helper function to convert a color component in sRGB space to linear | ||
| 588 | * RGB space. Used to build a static lookup table. | ||
| 589 | */ | ||
| 590 | private static int convertSRGBtoLinearRGB(int color) { | ||
| 591 | float input, output; | ||
| 592 | |||
| 593 | input = color / 255.0f; | ||
| 594 | if (input <= 0.04045f) { | ||
| 595 | output = input / 12.92f; | ||
| 596 | } else { | ||
| 597 | output = (float)Math.pow((input + 0.055) / 1.055, 2.4); | ||
| 598 | } | ||
| 599 | |||
| 600 | return Math.round(output * 255.0f); | ||
| 601 | } | ||
| 602 | |||
| 603 | /** | ||
| 604 | * Helper function to convert a color component in linear RGB space to | ||
| 605 | * SRGB space. Used to build a static lookup table. | ||
| 606 | */ | ||
| 607 | private static int convertLinearRGBtoSRGB(int color) { | ||
| 608 | float input, output; | ||
| 609 | |||
| 610 | input = color/255.0f; | ||
| 611 | if (input <= 0.0031308) { | ||
| 612 | output = input * 12.92f; | ||
| 613 | } else { | ||
| 614 | output = (1.055f * | ||
| 615 | ((float) Math.pow(input, (1.0 / 2.4)))) - 0.055f; | ||
| 616 | } | ||
| 617 | |||
| 618 | return Math.round(output * 255.0f); | ||
| 619 | } | ||
| 620 | |||
| 621 | /** | ||
| 622 | * {@inheritDoc} | ||
| 623 | */ | ||
| 624 | public final Raster getRaster(int x, int y, int w, int h) { | ||
| 625 | // If working raster is big enough, reuse it. Otherwise, | ||
| 626 | // build a large enough new one. | ||
| 627 | Raster raster = saved; | ||
| 628 | if (raster == null || | ||
| 629 | raster.getWidth() < w || raster.getHeight() < h) | ||
| 630 | { | ||
| 631 | raster = getCachedRaster(model, w, h); | ||
| 632 | saved = raster; | ||
| 633 | } | ||
| 634 | |||
| 635 | // Access raster internal int array. Because we use a DirectColorModel, | ||
| 636 | // we know the DataBuffer is of type DataBufferInt and the SampleModel | ||
| 637 | // is SinglePixelPackedSampleModel. | ||
| 638 | // Adjust for initial offset in DataBuffer and also for the scanline | ||
| 639 | // stride. | ||
| 640 | // These calls make the DataBuffer non-acceleratable, but the | ||
| 641 | // Raster is never Stable long enough to accelerate anyway... | ||
| 642 | DataBufferInt rasterDB = (DataBufferInt)raster.getDataBuffer(); | ||
| 643 | int[] pixels = rasterDB.getData(0); | ||
| 644 | int off = rasterDB.getOffset(); | ||
| 645 | int scanlineStride = ((SinglePixelPackedSampleModel) | ||
| 646 | raster.getSampleModel()).getScanlineStride(); | ||
| 647 | int adjust = scanlineStride - w; | ||
| 648 | |||
| 649 | fillRaster(pixels, off, adjust, x, y, w, h); // delegate to subclass | ||
| 650 | |||
| 651 | return raster; | ||
| 652 | } | ||
| 653 | |||
| 654 | protected abstract void fillRaster(int pixels[], int off, int adjust, | ||
| 655 | int x, int y, int w, int h); | ||
| 656 | |||
| 657 | |||
| 658 | /** | ||
| 659 | * Took this cacheRaster code from GradientPaint. It appears to recycle | ||
| 660 | * rasters for use by any other instance, as long as they are sufficiently | ||
| 661 | * large. | ||
| 662 | */ | ||
| 663 | private static synchronized Raster getCachedRaster(ColorModel cm, | ||
| 664 | int w, int h) | ||
| 665 | { | ||
| 666 | if (cm == cachedModel) { | ||
| 667 | if (cached != null) { | ||
| 668 | Raster ras = (Raster) cached.get(); | ||
| 669 | if (ras != null && | ||
| 670 | ras.getWidth() >= w && | ||
| 671 | ras.getHeight() >= h) | ||
| 672 | { | ||
| 673 | cached = null; | ||
| 674 | return ras; | ||
| 675 | } | ||
| 676 | } | ||
| 677 | } | ||
| 678 | return cm.createCompatibleWritableRaster(w, h); | ||
| 679 | } | ||
| 680 | |||
| 681 | /** | ||
| 682 | * Took this cacheRaster code from GradientPaint. It appears to recycle | ||
| 683 | * rasters for use by any other instance, as long as they are sufficiently | ||
| 684 | * large. | ||
| 685 | */ | ||
| 686 | private static synchronized void putCachedRaster(ColorModel cm, | ||
| 687 | Raster ras) | ||
| 688 | { | ||
| 689 | if (cached != null) { | ||
| 690 | Raster cras = (Raster) cached.get(); | ||
| 691 | if (cras != null) { | ||
| 692 | int cw = cras.getWidth(); | ||
| 693 | int ch = cras.getHeight(); | ||
| 694 | int iw = ras.getWidth(); | ||
| 695 | int ih = ras.getHeight(); | ||
| 696 | if (cw >= iw && ch >= ih) { | ||
| 697 | return; | ||
| 698 | } | ||
| 699 | if (cw * ch >= iw * ih) { | ||
| 700 | return; | ||
| 701 | } | ||
| 702 | } | ||
| 703 | } | ||
| 704 | cachedModel = cm; | ||
| 705 | cached = new WeakReference<Raster>(ras); | ||
| 706 | } | ||
| 707 | |||
| 708 | /** | ||
| 709 | * {@inheritDoc} | ||
| 710 | */ | ||
| 711 | public final void dispose() { | ||
| 712 | if (saved != null) { | ||
| 713 | putCachedRaster(model, saved); | ||
| 714 | saved = null; | ||
| 715 | } | ||
| 716 | } | ||
| 717 | |||
| 718 | /** | ||
| 719 | * {@inheritDoc} | ||
| 720 | */ | ||
| 721 | public final ColorModel getColorModel() { | ||
| 722 | return model; | ||
| 723 | } | ||
| 724 | } | ||