summaryrefslogtreecommitdiffstats
path: root/image/ICOFileHeaders.h
blob: aae5c99e82fa46f7bf9feb419f036bd895e525fb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */


#ifndef mozilla_image_ICOFileHeaders_h
#define mozilla_image_ICOFileHeaders_h

namespace mozilla {
namespace image {

#define ICONFILEHEADERSIZE 6
#define ICODIRENTRYSIZE 16
#define PNGSIGNATURESIZE 8
#define BMPFILEHEADERSIZE 14

/**
 * The header that comes right at the start of an icon file. (This
 * corresponds to the Windows ICONDIR structure.)
 */
struct IconFileHeader
{
  /**
   * Must be set to 0;
   */
  uint16_t   mReserved;
  /**
   * 1 for icon (.ICO) image (or 2 for cursor (.CUR) image (icon with the
   * addition of a hotspot), but we don't support cursor).
   */
  uint16_t   mType;
  /**
   * The number of BMP/PNG images contained in the icon file.
   */
  uint16_t   mCount;
};

/**
 * For each BMP/PNG image that the icon file contains there must be a
 * corresponding icon dir entry. (This corresponds to the Windows
 * ICONDIRENTRY structure.) These entries are encoded directly after the
 * IconFileHeader.
 */
struct IconDirEntry
{
  uint8_t   mWidth;
  uint8_t   mHeight;
  /**
   * The number of colors in the color palette of the BMP/PNG that this dir
   * entry corresponds to, or 0 if the image does not use a color palette.
   */
  uint8_t   mColorCount;
  /**
   * Should be set to 0.
   */
  uint8_t   mReserved;
  union {
    uint16_t mPlanes;   // ICO
    uint16_t mXHotspot; // CUR
  };
  union {
    uint16_t mBitCount; // ICO (bits per pixel)
    uint16_t mYHotspot; // CUR
  };
  /**
   * "bytes in resource" is the length of the encoded BMP/PNG that this dir
   * entry corresponds to.
   */
  uint32_t  mBytesInRes;
  /**
   * The offset of the start of the encoded BMP/PNG that this dir entry
   * corresponds to (from the start of the icon file).
   */
  uint32_t  mImageOffset;
};


} // namespace image
} // namespace mozilla

#endif // mozilla_image_ICOFileHeaders_h