01: /*
02: * Copyright 1998-1999 Sun Microsystems, Inc. All Rights Reserved.
03: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
04: *
05: * This code is free software; you can redistribute it and/or modify it
06: * under the terms of the GNU General Public License version 2 only, as
07: * published by the Free Software Foundation. Sun designates this
08: * particular file as subject to the "Classpath" exception as provided
09: * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22: * CA 95054 USA or visit www.sun.com if you need additional information or
23: * have any 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: */
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: */
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: */
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: */
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: */
94: public long getNativeIterator();
95: }
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