1// Copyright 2014 PDFium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6
7#ifndef CORE_FXCODEC_GIF_CFX_GIF_H_
8#define CORE_FXCODEC_GIF_CFX_GIF_H_
9
10#include <memory>
11#include <vector>
12
13class CFX_GifContext;
14
15extern const char* kGifSignature87;
16extern const char* kGifSignature89;
17
18#define GIF_SIG_EXTENSION 0x21
19#define GIF_SIG_IMAGE 0x2C
20#define GIF_SIG_TRAILER 0x3B
21#define GIF_BLOCK_GCE 0xF9
22#define GIF_BLOCK_PTE 0x01
23#define GIF_BLOCK_CE 0xFE
24#define GIF_BLOCK_TERMINAL 0x00
25#define GIF_MAX_LZW_EXP 12
26#define GIF_MAX_LZW_CODE 4096
27#define GIF_DATA_BLOCK 255
28#define GIF_D_STATUS_SIG 0x01
29#define GIF_D_STATUS_TAIL 0x02
30#define GIF_D_STATUS_EXT 0x03
31#define GIF_D_STATUS_EXT_CE 0x05
32#define GIF_D_STATUS_EXT_GCE 0x06
33#define GIF_D_STATUS_EXT_PTE 0x07
34#define GIF_D_STATUS_EXT_UNE 0x08
35#define GIF_D_STATUS_IMG_INFO 0x09
36#define GIF_D_STATUS_IMG_DATA 0x0A
37
38#pragma pack(1)
39typedef struct {
40  uint8_t pal_bits : 3;
41  uint8_t sort_flag : 1;
42  uint8_t color_resolution : 3;
43  uint8_t global_pal : 1;
44} CFX_GifGlobalFlags;
45
46typedef struct {
47  uint8_t pal_bits : 3;
48  uint8_t reserved : 2;
49  uint8_t sort_flag : 1;
50  uint8_t interlace : 1;
51  uint8_t local_pal : 1;
52} CFX_GifLocalFlags;
53
54typedef struct { char signature[6]; } CFX_GifHeader;
55
56typedef struct {
57  uint16_t width;
58  uint16_t height;
59  CFX_GifGlobalFlags global_flags;
60  uint8_t bc_index;
61  uint8_t pixel_aspect;
62} CFX_GifLocalScreenDescriptor;
63
64typedef struct {
65  uint16_t left;
66  uint16_t top;
67  uint16_t width;
68  uint16_t height;
69  CFX_GifLocalFlags local_flags;
70} CFX_CFX_GifImageInfo;
71
72typedef struct {
73  uint8_t transparency : 1;
74  uint8_t user_input : 1;
75  uint8_t disposal_method : 3;
76  uint8_t reserved : 3;
77} CFX_GifControlExtensionFlags;
78
79typedef struct {
80  uint8_t block_size;
81  CFX_GifControlExtensionFlags gce_flags;
82  uint16_t delay_time;
83  uint8_t trans_index;
84} CFX_GifGraphicControlExtension;
85
86typedef struct {
87  uint8_t block_size;
88  uint16_t grid_left;
89  uint16_t grid_top;
90  uint16_t grid_width;
91  uint16_t grid_height;
92
93  uint8_t char_width;
94  uint8_t char_height;
95
96  uint8_t fc_index;
97  uint8_t bc_index;
98} CFX_GifPlainTextExtension;
99
100typedef struct {
101  uint8_t block_size;
102  uint8_t app_identify[8];
103  uint8_t app_authentication[3];
104} GifApplicationExtension;
105
106typedef struct { uint8_t r, g, b; } CFX_GifPalette;
107#pragma pack()
108
109enum class CFX_GifDecodeStatus {
110  Error,
111  Success,
112  Unfinished,
113  InsufficientDestSize,  // Only used internally by CGifLZWDecoder::Decode()
114};
115
116typedef struct {
117  std::unique_ptr<CFX_GifGraphicControlExtension> image_GCE;
118  std::vector<CFX_GifPalette> local_palettes;
119  std::vector<uint8_t> row_buffer;
120  CFX_CFX_GifImageInfo image_info;
121  uint8_t local_pallette_exp;
122  uint8_t code_exp;
123  uint32_t data_pos;
124  int32_t row_num;
125} CFX_GifImage;
126
127#endif  // CORE_FXCODEC_GIF_CFX_GIF_H_
128