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1   /*
2    * Copyright (c) 2007, 2008, 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
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23   * questions.
24   */
25  
26  package sun.java2d.pipe.hw;
27  
28  import java.awt.BufferCapabilities;
29  import java.awt.ImageCapabilities;
30  
31  /**
32   * Provides extended BufferStrategy capabilities, allowing to specify
33   * the type of vertical refresh synchronization for a buffer strategy.
34   *
35   * This BS capability is always page flipping because v-sync is only relevant
36   * to flipping buffer strategies.
37   *
38   * Note that asking for a v-synced BS doesn't necessarily guarantee that it will
39   * be v-synced since the vsync capability may be disabled in the driver, or
40   * there may be other restriction (like a number of v-synced buffer strategies
41   * allowed per vm). Because of this {@code createBufferStrategy} doesn't
42   * throw {@code AWTException} when a v-synced BS could not be created when
43   * requested.
44   *
45   * @see java.awt.Canvas#createBufferStrategy(int, BufferCapabilities)
46   * @see java.awt.Window#createBufferStrategy(int, BufferCapabilities)
47   */
48  public class ExtendedBufferCapabilities extends BufferCapabilities {
49  
50      /**
51       * Type of synchronization on vertical retrace.
52       */
53      public static enum VSyncType {
54          /**
55           * Use the default v-sync mode appropriate for given BufferStrategy
56           * and situation.
57           */
58          VSYNC_DEFAULT(0),
59  
60          /**
61           * Synchronize flip on vertical retrace.
62           */
63          VSYNC_ON(1),
64  
65          /**
66           * Do not synchronize flip on vertical retrace.
67           */
68          VSYNC_OFF(2);
69  
70          /**
71           * Used to identify the v-sync type (independent of the constants
72           * order as opposed to {@code ordinal()}).
73           */
74          public int id() {
75              return id;
76          }
77  
78          private VSyncType(int id) {
79              this.id = id;
80          }
81          private int id;
82      }
83  
84      private VSyncType vsync;
85  
86      /**
87       * Creates an ExtendedBufferCapabilities object with front/back/flip caps
88       * from the passed cap, and VSYNC_DEFAULT v-sync mode.
89       */
90      public ExtendedBufferCapabilities(BufferCapabilities caps) {
91          super(caps.getFrontBufferCapabilities(),
92                caps.getBackBufferCapabilities(),
93                caps.getFlipContents());
94  
95          this.vsync = VSyncType.VSYNC_DEFAULT;
96      }
97  
98      /**
99       * Creates an ExtendedBufferCapabilities instance with front/back/flip caps
100      * from the passed caps, and VSYNC_DEFAULT v-sync mode.
101      */
102     public ExtendedBufferCapabilities(ImageCapabilities front,
103                                       ImageCapabilities back, FlipContents flip)
104     {
105         super(front, back, flip);
106 
107         this.vsync = VSyncType.VSYNC_DEFAULT;
108     }
109 
110     /**
111      * Creates an ExtendedBufferCapabilities instance with front/back/flip caps
112      * from the passed image/flip caps, and the v-sync type.
113      */
114     public ExtendedBufferCapabilities(ImageCapabilities front,
115                                       ImageCapabilities back, FlipContents flip,
116                                       VSyncType t)
117     {
118         super(front, back, flip);
119 
120         this.vsync = t;
121     }
122 
123     /**
124      * Creates an ExtendedBufferCapabilities instance with front/back/flip caps
125      * from the passed cap, and the passed v-sync mode.
126      */
127     public ExtendedBufferCapabilities(BufferCapabilities caps, VSyncType t) {
128         super(caps.getFrontBufferCapabilities(),
129               caps.getBackBufferCapabilities(),
130               caps.getFlipContents());
131 
132         this.vsync = t;
133     }
134 
135     /**
136      * Creates an ExtendedBufferCapabilities instance with front/back/flip caps
137      * from the object, and passed v-sync mode.
138      */
139     public ExtendedBufferCapabilities derive(VSyncType t) {
140         return new ExtendedBufferCapabilities(this, t);
141     }
142 
143     /**
144      * Returns the type of v-sync requested by this capabilities instance.
145      */
146     public VSyncType getVSync() {
147         return vsync;
148     }
149 
150     @Override
151     public final boolean isPageFlipping() {
152         return true;
153     }
154 }