1 /* 2 * Copyright (c) 1998, 2018, 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 /** 29 * This interface defines a general method for iterating through the 30 * rectangular "spans" that represent the interior of a filled path. 31 * <p> 32 * There can be many kinds of span iterators used in the rendering 33 * pipeline, the most basic being an iterator that scan converts a 34 * path defined by any PathIterator, or an nested iterator which 35 * intersects another iterator's spans with a clip region. 36 * Other iterators can be created for scan converting some of the 37 * primitive shapes more explicitly for speed or quality. 38 * 39 * @author Jim Graham 40 */ 41 public interface SpanIterator { 42 /** 43 * This method returns the bounding box of the spans that the 44 * iterator will be returning. 45 * The array must be of length at least 4 and upon return, it 46 * will be filled with the values: 47 * <pre> 48 * {PathMinX, PathMinY, PathMaxX, PathMaxY}. 49 * </pre> 50 */ getPathBox(int[] pathbox)51 public void getPathBox(int[] pathbox); 52 53 /** 54 * This method constrains the spans returned by nextSpan() to the 55 * rectangle whose bounds are given. 56 */ intersectClipBox(int lox, int loy, int hix, int hiy)57 public void intersectClipBox(int lox, int loy, int hix, int hiy); 58 59 /** 60 * This method returns the next span in the shape being iterated. 61 * The array must be of length at least 4 and upon return, it 62 * will be filled with the values: 63 * <pre> 64 * {SpanMinX, SpanMinY, SpanMaxX, SpanMaxY}. 65 * </pre> 66 */ nextSpan(int[] spanbox)67 public boolean nextSpan(int[] spanbox); 68 69 /** 70 * This method tells the iterator that it may skip all spans 71 * whose Y range is completely above the indicated Y coordinate. 72 * This method is used to provide feedback from the caller when 73 * clipping prevents the display of any data in a given Y range. 74 * Typically it will only be called when this iterator has returned 75 * a span whose MaxY coordinate is less than the indicated Y and 76 * the calling mechanism wants to avoid unnecessary iteration work. 77 * While this request could technically be ignored (i.e. a NOP), 78 * doing so could potentially cause the caller to make this callback 79 * for each span that is being skipped. 80 */ skipDownTo(int y)81 public void skipDownTo(int y); 82 83 /** 84 * This method returns a native pointer to a function block that 85 * can be used by a native method to perform the same iteration 86 * cycle that the above methods provide while avoiding upcalls to 87 * the Java object. 88 * The definition of the structure whose pointer is returned by 89 * this method is defined in: 90 * <pre> 91 * src/share/native/sun/java2d/pipe/SpanIterator.h 92 * </pre> 93 */ getNativeIterator()94 public long getNativeIterator(); 95 } 96