1/*
2 * Copyright (c) 1998, 2016, 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
26package sun.java2d.pipe;
27
28import java.awt.geom.PathIterator;
29import java.awt.Rectangle;
30import 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 */
65public final class ShapeSpanIterator
66    implements SpanIterator, PathConsumer2D
67{
68    long pData;
69
70    static {
71        initIDs();
72    }
73
74    public static native void initIDs();
75
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     */
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     */
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     */
105    private native void setNormalize(boolean adjust);
106
107    /*
108     * Sets the rectangle of interest for storing and returning
109     * span segments.
110     */
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     */
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     */
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     */
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     */
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     */
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     */
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     */
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     */
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     */
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     */
184    public native long getNativeIterator();
185
186    /*
187     * Cleans out all internal data structures.
188     */
189    public native void dispose();
190
191    public native void moveTo(float x, float y);
192    public native void lineTo(float x, float y);
193    public native void quadTo(float x1, float y1,
194                              float x2, float y2);
195    public native void curveTo(float x1, float y1,
196                               float x2, float y2,
197                               float x3, float y3);
198    public native void closePath();
199    public native void pathDone();
200    public native long getNativeConsumer();
201}
202