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 import java.awt.geom.PathIterator; 29 import java.awt.Rectangle; 30 import sun.awt.geom.PathConsumer2D; 31 32 /** 33 * This class can iterate individual span elements generated by scan 34 * converting a Shape. 35 * This particular implementation flattens the incoming path and then 36 * performs simple polygon tracing to calculate the spans. 37 * 38 * Note that this class holds pointers to native data which must be 39 * disposed. It is not marked as finalizable since it is intended 40 * to be very lightweight and finalization is a comparitively expensive 41 * procedure. The caller must specifically use try{} finally{} to 42 * manually ensure that the object is disposed after use, otherwise 43 * native data structures might be leaked. 44 * 45 * Here is a code sample for using this class: 46 * 47 * public void fillShape(Shape s, Rectangle clipRect) { 48 * ShapeSpanIterator ssi = new ShapeSpanIterator(false); 49 * try { 50 * ssi.setOutputArea(clipRect); 51 * ssi.appendPath(s.getPathIterator(null)); 52 * int spanbox[] = new int[4]; 53 * while (ssi.nextSpan(spanbox)) { 54 * int x = spanbox[0]; 55 * int y = spanbox[1]; 56 * int w = spanbox[2] - x; 57 * int h = spanbox[3] - y; 58 * fillRect(x, y, w, h); 59 * } 60 * } finally { 61 * ssi.dispose(); 62 * } 63 * } 64 */ 65 public final class ShapeSpanIterator 66 implements SpanIterator, PathConsumer2D 67 { 68 long pData; 69 70 static { initIDs()71 initIDs(); 72 } 73 initIDs()74 public static native void initIDs(); 75 ShapeSpanIterator(boolean adjust)76 public ShapeSpanIterator(boolean adjust) { 77 setNormalize(adjust); 78 } 79 80 /* 81 * Appends the geometry and winding rule from the indicated 82 * path iterator. 83 */ appendPath(PathIterator pi)84 public void appendPath(PathIterator pi) { 85 float[] coords = new float[6]; 86 87 setRule(pi.getWindingRule()); 88 while (!pi.isDone()) { 89 addSegment(pi.currentSegment(coords), coords); 90 pi.next(); 91 } 92 pathDone(); 93 } 94 95 /* 96 * Appends the geometry from the indicated set of polygon points. 97 */ appendPoly(int[] xPoints, int[] yPoints, int nPoints, int xoff, int yoff)98 public native void appendPoly(int[] xPoints, int[] yPoints, int nPoints, 99 int xoff, int yoff); 100 101 /* 102 * Sets the normalization flag so that incoming data is 103 * adjusted to nearest (0.25, 0.25) subpixel position. 104 */ setNormalize(boolean adjust)105 private native void setNormalize(boolean adjust); 106 107 /* 108 * Sets the rectangle of interest for storing and returning 109 * span segments. 110 */ setOutputAreaXYWH(int x, int y, int w, int h)111 public void setOutputAreaXYWH(int x, int y, int w, int h) { 112 setOutputAreaXYXY(x, y, Region.dimAdd(x, w), Region.dimAdd(y, h)); 113 } 114 115 /* 116 * Sets the rectangle of interest for storing and returning 117 * span segments. 118 */ setOutputAreaXYXY(int lox, int loy, int hix, int hiy)119 public native void setOutputAreaXYXY(int lox, int loy, int hix, int hiy); 120 121 /* 122 * Sets the rectangle of interest for storing and returning 123 * span segments to the specified Rectangle. 124 */ setOutputArea(Rectangle r)125 public void setOutputArea(Rectangle r) { 126 setOutputAreaXYWH(r.x, r.y, r.width, r.height); 127 } 128 129 /* 130 * Sets the rectangle of interest for storing and returning 131 * span segments to the bounds of the specified Region. 132 */ setOutputArea(Region r)133 public void setOutputArea(Region r) { 134 setOutputAreaXYXY(r.getLoX(), r.getLoY(), r.getHiX(), r.getHiY()); 135 } 136 137 /* 138 * Sets the winding rule in the native data structures. 139 */ setRule(int rule)140 public native void setRule(int rule); 141 142 /* 143 * Adds a single PathIterator segment to the internal list of 144 * path element structures. 145 */ addSegment(int type, float[] coords)146 public native void addSegment(int type, float[] coords); 147 148 /* 149 * Gets the bbox of the available path segments, clipped to the 150 * OutputArea. 151 */ getPathBox(int[] pathbox)152 public native void getPathBox(int[] pathbox); 153 154 /* 155 * Intersects the path box with the given bbox. 156 * Returned spans are clipped to this region, or discarded 157 * altogether if they lie outside it. 158 */ intersectClipBox(int lox, int loy, int hix, int hiy)159 public native void intersectClipBox(int lox, int loy, int hix, int hiy); 160 161 /* 162 * Fetches the next span that needs to be operated on. 163 * If the return value is false then there are no more spans. 164 */ nextSpan(int[] spanbox)165 public native boolean nextSpan(int[] spanbox); 166 167 /** 168 * This method tells the iterator that it may skip all spans 169 * whose Y range is completely above the indicated Y coordinate. 170 */ skipDownTo(int y)171 public native void skipDownTo(int y); 172 173 /** 174 * This method returns a native pointer to a function block that 175 * can be used by a native method to perform the same iteration 176 * cycle that the above methods provide while avoiding upcalls to 177 * the Java object. 178 * The definition of the structure whose pointer is returned by 179 * this method is defined in: 180 * <pre> 181 * src/share/native/sun/java2d/pipe/SpanIterator.h 182 * </pre> 183 */ getNativeIterator()184 public native long getNativeIterator(); 185 186 /* 187 * Cleans out all internal data structures. 188 */ dispose()189 public native void dispose(); 190 moveTo(float x, float y)191 public native void moveTo(float x, float y); lineTo(float x, float y)192 public native void lineTo(float x, float y); quadTo(float x1, float y1, float x2, float y2)193 public native void quadTo(float x1, float y1, 194 float x2, float y2); curveTo(float x1, float y1, float x2, float y2, float x3, float y3)195 public native void curveTo(float x1, float y1, 196 float x2, float y2, 197 float x3, float y3); closePath()198 public native void closePath(); pathDone()199 public native void pathDone(); getNativeConsumer()200 public native long getNativeConsumer(); 201 } 202