1 /*
   2  * Copyright (c) 2007, 2013, 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 sun.java2d.pipe;
  27 
  28 import java.awt.Shape;
  29 import java.awt.BasicStroke;
  30 import java.awt.geom.PathIterator;
  31 import java.awt.geom.AffineTransform;
  32 
  33 import java.security.PrivilegedAction;
  34 import java.security.AccessController;
  35 import sun.security.action.GetPropertyAction;
  36 
  37 import sun.awt.geom.PathConsumer2D;
  38 
  39 /**
  40  * This class abstracts a number of features for which the Java 2D
  41  * implementation relies on proprietary licensed software libraries.
  42  * Access to those features is now achieved by retrieving the singleton
  43  * instance of this class and calling the appropriate methods on it.
  44  * The 3 primary features abstracted here include:
  45  * <dl>
  46  * <dt>Shape createStrokedShape(Shape, [BasicStroke attributes]);
  47  * <dd>This method implements the functionality of the method of the
  48  * same name on the {@link BasicStroke} class.
  49  * <dt>void strokeTo(Shape, [rendering parameters], PathConsumer2D);
  50  * <dd>This method performs widening of the source path on the fly
  51  * and sends the results to the given {@link PathConsumer2D} object.
  52  * This procedure avoids having to create an intermediate Shape
  53  * object to hold the results of the {@code createStrokedShape} method.
  54  * The main user of this method is the Java 2D non-antialiasing renderer.
  55  * <dt>AATileGenerator getAATileGenerator(Shape, [rendering parameters]);
  56  * <dd>This method returns an object which can iterate over the
  57  * specified bounding box and produce tiles of coverage values for
  58  * antialiased rendering.  The details of the operation of the
  59  * {@link AATileGenerator} object are explained in its class comments.
  60  * </dl>
  61  * Additionally, the following informational method supplies important
  62  * data about the implementation.
  63  * <dl>
  64  * <dt>float getMinimumAAPenSize()
  65  * <dd>This method provides information on how small the BasicStroke
  66  * line width can get before dropouts occur.  Rendering with a BasicStroke
  67  * is defined to never allow the line to have breaks, gaps, or dropouts
  68  * even if the width is set to 0.0f, so this information allows the
  69  * {@link sun.java2d.SunGraphics2D} class to detect the "thin line" case and set
  70  * the rendering attributes accordingly.
  71  * </dl>
  72  * At startup the runtime will load a single instance of this class.
  73  * It searches the classpath for a registered provider of this API
  74  * and returns either the last one it finds, or the instance whose
  75  * class name matches the value supplied in the System property
  76  * {@code sun.java2d.renderer}.
  77  * Additionally, a runtime System property flag can be set to trace
  78  * all calls to methods on the {@code RenderingEngine} in use by
  79  * setting the sun.java2d.renderer.trace property to any non-null value.
  80  * <p>
  81  * Parts of the system that need to use any of the above features should
  82  * call {@code RenderingEngine.getInstance()} to obtain the properly
  83  * registered (and possibly trace-enabled) version of the RenderingEngine.
  84  */
  85 public abstract class RenderingEngine {
  86     private static RenderingEngine reImpl;
  87 
  88     /**
  89      * Returns an instance of {@code RenderingEngine} as determined
  90      * by the installation environment and runtime flags.
  91      * <p>
  92      * A specific instance of the {@code RenderingEngine} can be
  93      * chosen by specifying the runtime flag:
  94      * <pre>
  95      *     java -Dsun.java2d.renderer=&lt;classname&gt;
  96      * </pre>
  97      *
  98      * If no specific {@code RenderingEngine} is specified on the command
  99      * line or the requested class fails to load, then the Marlin
 100      * renderer will be used as the default.
 101      * <p>
 102      * A printout of which RenderingEngine is loaded and used can be
 103      * enabled by specifying the runtime flag:
 104      * <pre>
 105      *     java -Dsun.java2d.renderer.verbose=true
 106      * </pre>
 107      * <p>
 108      * Runtime tracing of the actions of the {@code RenderingEngine}
 109      * can be enabled by specifying the runtime flag:
 110      * <pre>
 111      *     java -Dsun.java2d.renderer.trace=&lt;any string&gt;
 112      * </pre>
 113      * @return an instance of {@code RenderingEngine}
 114      * @since 1.7
 115      */
 116     public static synchronized RenderingEngine getInstance() {
 117         if (reImpl != null) {
 118             return reImpl;
 119         }
 120 
 121         /* Look first for an app-override renderer,
 122          * if not specified or present, then look for marlin.
 123          */


 124         GetPropertyAction gpa =
 125             new GetPropertyAction("sun.java2d.renderer");
 126         String reClass = AccessController.doPrivileged(gpa);
 127         if (reClass != null) {
 128             try {
 129                 Class<?> cls = Class.forName(reClass);
 130                 reImpl = (RenderingEngine) cls.newInstance();
 131             } catch (ReflectiveOperationException ignored0) {
 132             }
 133         }
 134         if (reImpl == null) {
 135             final String marlinREClass = "sun.java2d.marlin.MarlinRenderingEngine";
 136             try {
 137                 Class<?> cls = Class.forName(marlinREClass);
 138                 reImpl = (RenderingEngine) cls.newInstance();
 139             } catch (ReflectiveOperationException ignored1) {
 140             }
 141         }
 142 
 143         if (reImpl == null) {
 144             throw new InternalError("No RenderingEngine module found");
 145         }
 146 
 147         gpa = new GetPropertyAction("sun.java2d.renderer.verbose");
 148         String verbose = AccessController.doPrivileged(gpa);
 149         if (verbose != null && verbose.startsWith("t")) {
 150             System.out.println("RenderingEngine = "+reImpl);
 151         }
 152 
 153         gpa = new GetPropertyAction("sun.java2d.renderer.trace");
 154         String reTrace = AccessController.doPrivileged(gpa);
 155         if (reTrace != null) {
 156             reImpl = new Tracer(reImpl);
 157         }
 158 
 159         return reImpl;
 160     }
 161 
 162     /**
 163      * Create a widened path as specified by the parameters.
 164      * <p>
 165      * The specified {@code src} {@link Shape} is widened according
 166      * to the specified attribute parameters as per the
 167      * {@link BasicStroke} specification.
 168      *
 169      * @param src the source path to be widened
 170      * @param width the width of the widened path as per {@code BasicStroke}
 171      * @param caps the end cap decorations as per {@code BasicStroke}
 172      * @param join the segment join decorations as per {@code BasicStroke}
 173      * @param miterlimit the miter limit as per {@code BasicStroke}
 174      * @param dashes the dash length array as per {@code BasicStroke}
 175      * @param dashphase the initial dash phase as per {@code BasicStroke}
 176      * @return the widened path stored in a new {@code Shape} object
 177      * @since 1.7
 178      */
 179     public abstract Shape createStrokedShape(Shape src,
 180                                              float width,
 181                                              int caps,
 182                                              int join,
 183                                              float miterlimit,
 184                                              float dashes[],
 185                                              float dashphase);
 186 
 187     /**
 188      * Sends the geometry for a widened path as specified by the parameters
 189      * to the specified consumer.
 190      * <p>
 191      * The specified {@code src} {@link Shape} is widened according
 192      * to the parameters specified by the {@link BasicStroke} object.
 193      * Adjustments are made to the path as appropriate for the
 194      * {@link java.awt.RenderingHints#VALUE_STROKE_NORMALIZE} hint if the
 195      * {@code normalize} boolean parameter is true.
 196      * Adjustments are made to the path as appropriate for the
 197      * {@link java.awt.RenderingHints#VALUE_ANTIALIAS_ON} hint if the
 198      * {@code antialias} boolean parameter is true.
 199      * <p>
 200      * The geometry of the widened path is forwarded to the indicated
 201      * {@link PathConsumer2D} object as it is calculated.
 202      *
 203      * @param src the source path to be widened
 204      * @param bs the {@code BasicSroke} object specifying the
 205      *           decorations to be applied to the widened path
 206      * @param normalize indicates whether stroke normalization should
 207      *                  be applied
 208      * @param antialias indicates whether or not adjustments appropriate
 209      *                  to antialiased rendering should be applied
 210      * @param consumer the {@code PathConsumer2D} instance to forward
 211      *                 the widened geometry to
 212      * @since 1.7
 213      */
 214     public abstract void strokeTo(Shape src,
 215                                   AffineTransform at,
 216                                   BasicStroke bs,
 217                                   boolean thin,
 218                                   boolean normalize,
 219                                   boolean antialias,
 220                                   PathConsumer2D consumer);
 221 
 222     /**
 223      * Construct an antialiased tile generator for the given shape with
 224      * the given rendering attributes and store the bounds of the tile
 225      * iteration in the bbox parameter.
 226      * The {@code at} parameter specifies a transform that should affect
 227      * both the shape and the {@code BasicStroke} attributes.
 228      * The {@code clip} parameter specifies the current clip in effect
 229      * in device coordinates and can be used to prune the data for the
 230      * operation, but the renderer is not required to perform any
 231      * clipping.
 232      * If the {@code BasicStroke} parameter is null then the shape
 233      * should be filled as is, otherwise the attributes of the
 234      * {@code BasicStroke} should be used to specify a draw operation.
 235      * The {@code thin} parameter indicates whether or not the
 236      * transformed {@code BasicStroke} represents coordinates smaller
 237      * than the minimum resolution of the antialiasing rasterizer as
 238      * specified by the {@code getMinimumAAPenWidth()} method.
 239      * <p>
 240      * Upon returning, this method will fill the {@code bbox} parameter
 241      * with 4 values indicating the bounds of the iteration of the
 242      * tile generator.
 243      * The iteration order of the tiles will be as specified by the
 244      * pseudo-code:
 245      * <pre>
 246      *     for (y = bbox[1]; y < bbox[3]; y += tileheight) {
 247      *         for (x = bbox[0]; x < bbox[2]; x += tilewidth) {
 248      *         }
 249      *     }
 250      * </pre>
 251      * If there is no output to be rendered, this method may return
 252      * null.
 253      *
 254      * @param s the shape to be rendered (fill or draw)
 255      * @param at the transform to be applied to the shape and the
 256      *           stroke attributes
 257      * @param clip the current clip in effect in device coordinates
 258      * @param bs if non-null, a {@code BasicStroke} whose attributes
 259      *           should be applied to this operation
 260      * @param thin true if the transformed stroke attributes are smaller
 261      *             than the minimum dropout pen width
 262      * @param normalize true if the {@code VALUE_STROKE_NORMALIZE}
 263      *                  {@code RenderingHint} is in effect
 264      * @param bbox returns the bounds of the iteration
 265      * @return the {@code AATileGenerator} instance to be consulted
 266      *         for tile coverages, or null if there is no output to render
 267      * @since 1.7
 268      */
 269     public abstract AATileGenerator getAATileGenerator(Shape s,
 270                                                        AffineTransform at,
 271                                                        Region clip,
 272                                                        BasicStroke bs,
 273                                                        boolean thin,
 274                                                        boolean normalize,
 275                                                        int bbox[]);
 276 
 277     /**
 278      * Construct an antialiased tile generator for the given parallelogram
 279      * store the bounds of the tile iteration in the bbox parameter.
 280      * The parallelogram is specified as a starting point and 2 delta
 281      * vectors that indicate the slopes of the 2 pairs of sides of the
 282      * parallelogram.
 283      * The 4 corners of the parallelogram are defined by the 4 points:
 284      * <ul>
 285      * <li> {@code x}, {@code y}
 286      * <li> {@code x+dx1}, {@code y+dy1}
 287      * <li> {@code x+dx1+dx2}, {@code y+dy1+dy2}
 288      * <li> {@code x+dx2}, {@code y+dy2}
 289      * </ul>
 290      * The {@code lw1} and {@code lw2} parameters provide a specification
 291      * for an optionally stroked parallelogram if they are positive numbers.
 292      * The {@code lw1} parameter is the ratio of the length of the {@code dx1},
 293      * {@code dx2} delta vector to half of the line width in that same
 294      * direction.
 295      * The {@code lw2} parameter provides the same ratio for the other delta
 296      * vector.
 297      * If {@code lw1} and {@code lw2} are both greater than zero, then
 298      * the parallelogram figure is doubled by both expanding and contracting
 299      * each delta vector by its corresponding {@code lw} value.
 300      * If either (@code lw1) or {@code lw2} are also greater than 1, then
 301      * the inner (contracted) parallelogram disappears and the figure is
 302      * simply a single expanded parallelogram.
 303      * The {@code clip} parameter specifies the current clip in effect
 304      * in device coordinates and can be used to prune the data for the
 305      * operation, but the renderer is not required to perform any
 306      * clipping.
 307      * <p>
 308      * Upon returning, this method will fill the {@code bbox} parameter
 309      * with 4 values indicating the bounds of the iteration of the
 310      * tile generator.
 311      * The iteration order of the tiles will be as specified by the
 312      * pseudo-code:
 313      * <pre>
 314      *     for (y = bbox[1]; y < bbox[3]; y += tileheight) {
 315      *         for (x = bbox[0]; x < bbox[2]; x += tilewidth) {
 316      *         }
 317      *     }
 318      * </pre>
 319      * If there is no output to be rendered, this method may return
 320      * null.
 321      *
 322      * @param x the X coordinate of the first corner of the parallelogram
 323      * @param y the Y coordinate of the first corner of the parallelogram
 324      * @param dx1 the X coordinate delta of the first leg of the parallelogram
 325      * @param dy1 the Y coordinate delta of the first leg of the parallelogram
 326      * @param dx2 the X coordinate delta of the second leg of the parallelogram
 327      * @param dy2 the Y coordinate delta of the second leg of the parallelogram
 328      * @param lw1 the line width ratio for the first leg of the parallelogram
 329      * @param lw2 the line width ratio for the second leg of the parallelogram
 330      * @param clip the current clip in effect in device coordinates
 331      * @param bbox returns the bounds of the iteration
 332      * @return the {@code AATileGenerator} instance to be consulted
 333      *         for tile coverages, or null if there is no output to render
 334      * @since 1.7
 335      */
 336     public abstract AATileGenerator getAATileGenerator(double x, double y,
 337                                                        double dx1, double dy1,
 338                                                        double dx2, double dy2,
 339                                                        double lw1, double lw2,
 340                                                        Region clip,
 341                                                        int bbox[]);
 342 
 343     /**
 344      * Returns the minimum pen width that the antialiasing rasterizer
 345      * can represent without dropouts occurring.
 346      * @since 1.7
 347      */
 348     public abstract float getMinimumAAPenSize();
 349 
 350     /**
 351      * Utility method to feed a {@link PathConsumer2D} object from a
 352      * given {@link PathIterator}.
 353      * This method deals with the details of running the iterator and
 354      * feeding the consumer a segment at a time.
 355      */
 356     public static void feedConsumer(PathIterator pi, PathConsumer2D consumer) {
 357         float coords[] = new float[6];
 358         while (!pi.isDone()) {
 359             switch (pi.currentSegment(coords)) {
 360             case PathIterator.SEG_MOVETO:
 361                 consumer.moveTo(coords[0], coords[1]);
 362                 break;
 363             case PathIterator.SEG_LINETO:
 364                 consumer.lineTo(coords[0], coords[1]);
 365                 break;
 366             case PathIterator.SEG_QUADTO:
 367                 consumer.quadTo(coords[0], coords[1],
 368                                 coords[2], coords[3]);
 369                 break;
 370             case PathIterator.SEG_CUBICTO:
 371                 consumer.curveTo(coords[0], coords[1],
 372                                  coords[2], coords[3],
 373                                  coords[4], coords[5]);
 374                 break;
 375             case PathIterator.SEG_CLOSE:
 376                 consumer.closePath();
 377                 break;
 378             }
 379             pi.next();
 380         }
 381     }
 382 
 383     static class Tracer extends RenderingEngine {
 384         RenderingEngine target;
 385         String name;
 386 
 387         public Tracer(RenderingEngine target) {
 388             this.target = target;
 389             name = target.getClass().getName();
 390         }
 391 
 392         public Shape createStrokedShape(Shape src,
 393                                         float width,
 394                                         int caps,
 395                                         int join,
 396                                         float miterlimit,
 397                                         float dashes[],
 398                                         float dashphase)
 399         {
 400             System.out.println(name+".createStrokedShape("+
 401                                src.getClass().getName()+", "+
 402                                "width = "+width+", "+
 403                                "caps = "+caps+", "+
 404                                "join = "+join+", "+
 405                                "miter = "+miterlimit+", "+
 406                                "dashes = "+dashes+", "+
 407                                "dashphase = "+dashphase+")");
 408             return target.createStrokedShape(src,
 409                                              width, caps, join, miterlimit,
 410                                              dashes, dashphase);
 411         }
 412 
 413         public void strokeTo(Shape src,
 414                              AffineTransform at,
 415                              BasicStroke bs,
 416                              boolean thin,
 417                              boolean normalize,
 418                              boolean antialias,
 419                              PathConsumer2D consumer)
 420         {
 421             System.out.println(name+".strokeTo("+
 422                                src.getClass().getName()+", "+
 423                                at+", "+
 424                                bs+", "+
 425                                (thin ? "thin" : "wide")+", "+
 426                                (normalize ? "normalized" : "pure")+", "+
 427                                (antialias ? "AA" : "non-AA")+", "+
 428                                consumer.getClass().getName()+")");
 429             target.strokeTo(src, at, bs, thin, normalize, antialias, consumer);
 430         }
 431 
 432         public float getMinimumAAPenSize() {
 433             System.out.println(name+".getMinimumAAPenSize()");
 434             return target.getMinimumAAPenSize();
 435         }
 436 
 437         public AATileGenerator getAATileGenerator(Shape s,
 438                                                   AffineTransform at,
 439                                                   Region clip,
 440                                                   BasicStroke bs,
 441                                                   boolean thin,
 442                                                   boolean normalize,
 443                                                   int bbox[])
 444         {
 445             System.out.println(name+".getAATileGenerator("+
 446                                s.getClass().getName()+", "+
 447                                at+", "+
 448                                clip+", "+
 449                                bs+", "+
 450                                (thin ? "thin" : "wide")+", "+
 451                                (normalize ? "normalized" : "pure")+")");
 452             return target.getAATileGenerator(s, at, clip,
 453                                              bs, thin, normalize,
 454                                              bbox);
 455         }
 456         public AATileGenerator getAATileGenerator(double x, double y,
 457                                                   double dx1, double dy1,
 458                                                   double dx2, double dy2,
 459                                                   double lw1, double lw2,
 460                                                   Region clip,
 461                                                   int bbox[])
 462         {
 463             System.out.println(name+".getAATileGenerator("+
 464                                x+", "+y+", "+
 465                                dx1+", "+dy1+", "+
 466                                dx2+", "+dy2+", "+
 467                                lw1+", "+lw2+", "+
 468                                clip+")");
 469             return target.getAATileGenerator(x, y,
 470                                              dx1, dy1,
 471                                              dx2, dy2,
 472                                              lw1, lw2,
 473                                              clip, bbox);
 474         }
 475     }
 476 }
--- EOF ---