1/*
2 * Copyright (c) 1996, 2012, 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/*
27 * This file contains macro definitions for the Decoding category of
28 * the macros used by the generic scaleloop function.
29 *
30 * This implementation can decode the pixel information associated
31 * with Java DirectColorModel objects where the color masks are
32 * guaranteed to be at least 8-bits wide each.  It is slightly more
33 * efficient then the generic DCM parsing code since it does not need
34 * to store or test component scaling values.  This implementation
35 * examines some of the private fields of the DirectColorModel
36 * object and decodes the red, green, blue, and possibly alpha values
37 * directly rather than calling the getRGB method on the Java object.
38 */
39
40/*
41 * These definitions vector the standard macro names to the "DCM8"
42 * versions of those macros only if the "DecodeDeclared" keyword has
43 * not yet been defined elsewhere.  The "DecodeDeclared" keyword is
44 * also defined here to claim ownership of the primary implementation
45 * even though this file does not rely on the definitions in any other
46 * files.
47 */
48#ifndef DecodeDeclared
49#define DeclareDecodeVars       DeclareDCM8Vars
50#define InitPixelDecode(CM)     InitPixelDCM8(unhand(CM))
51#define PixelDecode             PixelDCM8Decode
52#define DecodeDeclared
53#endif
54
55#define DeclareDCM8Vars                                         \
56    IfAlpha(unsigned int alpha_off;)                            \
57    unsigned int red_off, green_off, blue_off;
58
59#define InitPixelDCM8(CM)                                               \
60    do {                                                                \
61        Classjava_awt_image_DirectColorModel *dcm =                     \
62            (Classjava_awt_image_DirectColorModel *) CM;                \
63        red_off = dcm->red_offset;                                      \
64        green_off = dcm->green_offset;                                  \
65        blue_off = dcm->blue_offset;                                    \
66        IfAlpha(alpha_off = (dcm->alpha_mask == 0                       \
67                             ? -1                                       \
68                             : dcm->alpha_offset);)                     \
69    } while (0)
70
71#define PixelDCM8Decode(CM, pixel, red, green, blue, alpha)             \
72    do {                                                                \
73        IfAlpha(alpha = ((alpha_off < 0)                                \
74                         ? 255                                          \
75                         : (pixel >> alpha_off) & 0xff);)               \
76        red = (pixel >> red_off) & 0xff;                                \
77        green = (pixel >> green_off) & 0xff;                            \
78        blue = (pixel >> blue_off) & 0xff;                              \
79    } while (0)
80