1 /**************************************************************************** 2 3 gif_lib_private.h - internal giflib routines and structures 4 5 SPDX-License-Identifier: MIT 6 7 ****************************************************************************/ 8 9 #ifndef _GIF_LIB_PRIVATE_H 10 #define _GIF_LIB_PRIVATE_H 11 12 #include "gif_hash.h" 13 #include "gif_lib.h" 14 15 #ifndef SIZE_MAX 16 #define SIZE_MAX UINTPTR_MAX 17 #endif 18 19 #define EXTENSION_INTRODUCER 0x21 20 #define DESCRIPTOR_INTRODUCER 0x2c 21 #define TERMINATOR_INTRODUCER 0x3b 22 23 #define LZ_MAX_CODE 4095 /* Biggest code possible in 12 bits. */ 24 #define LZ_BITS 12 25 26 #define FLUSH_OUTPUT 4096 /* Impossible code, to signal flush. */ 27 #define FIRST_CODE 4097 /* Impossible code, to signal first. */ 28 #define NO_SUCH_CODE 4098 /* Impossible code, to signal empty. */ 29 30 #define FILE_STATE_WRITE 0x01 31 #define FILE_STATE_SCREEN 0x02 32 #define FILE_STATE_IMAGE 0x04 33 #define FILE_STATE_READ 0x08 34 35 #define IS_READABLE(Private) (Private->FileState & FILE_STATE_READ) 36 #define IS_WRITEABLE(Private) (Private->FileState & FILE_STATE_WRITE) 37 38 typedef struct GifFilePrivateType { 39 GifWord FileState, FileHandle, /* Where all this data goes to! */ 40 BitsPerPixel, /* Bits per pixel (Codes uses at least this + 1). */ 41 ClearCode, /* The CLEAR LZ code. */ 42 EOFCode, /* The EOF LZ code. */ 43 RunningCode, /* The next code algorithm can generate. */ 44 RunningBits, /* The number of bits required to represent 45 RunningCode. */ 46 MaxCode1, /* 1 bigger than max. possible code, in RunningBits bits. 47 */ 48 LastCode, /* The code before the current code. */ 49 CrntCode, /* Current algorithm code. */ 50 StackPtr, /* For character stack (see below). */ 51 CrntShiftState; /* Number of bits in CrntShiftDWord. */ 52 unsigned long CrntShiftDWord; /* For bytes decomposition into codes. */ 53 unsigned long PixelCount; /* Number of pixels in image. */ 54 FILE *File; /* File as stream. */ 55 InputFunc Read; /* function to read gif input (TVT) */ 56 OutputFunc Write; /* function to write gif output (MRB) */ 57 GifByteType Buf[256]; /* Compressed input is buffered here. */ 58 GifByteType Stack[LZ_MAX_CODE]; /* Decoded pixels are stacked here. */ 59 GifByteType Suffix[LZ_MAX_CODE + 1]; /* So we can trace the codes. */ 60 GifPrefixType Prefix[LZ_MAX_CODE + 1]; 61 GifHashTableType *HashTable; 62 bool gif89; 63 } GifFilePrivateType; 64 65 #ifndef HAVE_REALLOCARRAY 66 extern void *openbsd_reallocarray(void *optr, size_t nmemb, size_t size); 67 #define reallocarray openbsd_reallocarray 68 #endif 69 70 #endif /* _GIF_LIB_PRIVATE_H */ 71 72 /* end */ 73