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Diffstat (limited to 'libpng/infutil.h')
| -rw-r--r-- | libpng/infutil.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/libpng/infutil.h b/libpng/infutil.h new file mode 100644 index 0000000..99d1135 --- /dev/null +++ b/libpng/infutil.h @@ -0,0 +1,98 @@ +/* infutil.h -- types and macros common to blocks and codes + * Copyright (C) 1995-1998 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* WARNING: this file should *not* be used by applications. It is + part of the implementation of the compression library and is + subject to change. Applications should only use zlib.h. + */ + +#ifndef _INFUTIL_H +#define _INFUTIL_H + +typedef enum { + TYPE, /* get type bits (3, including end bit) */ + LENS, /* get lengths for stored */ + STORED, /* processing stored block */ + TABLE, /* get table lengths */ + BTREE, /* get bit lengths tree for a dynamic block */ + DTREE, /* get length, distance trees for a dynamic block */ + CODES, /* processing fixed or dynamic block */ + DRY, /* output remaining window bytes */ + DONE, /* finished last block, done */ + BAD} /* got a data error--stuck here */ +inflate_block_mode; + +/* inflate blocks semi-private state */ +struct inflate_blocks_state { + + /* mode */ + inflate_block_mode mode; /* current inflate_block mode */ + + /* mode dependent information */ + union { + uInt left; /* if STORED, bytes left to copy */ + struct { + uInt table; /* table lengths (14 bits) */ + uInt index; /* index into blens (or border) */ + uIntf *blens; /* bit lengths of codes */ + uInt bb; /* bit length tree depth */ + inflate_huft *tb; /* bit length decoding tree */ + } trees; /* if DTREE, decoding info for trees */ + struct { + inflate_codes_statef + *codes; + } decode; /* if CODES, current state */ + } sub; /* submode */ + uInt last; /* true if this block is the last block */ + + /* mode independent information */ + uInt bitk; /* bits in bit buffer */ + uLong bitb; /* bit buffer */ + inflate_huft *hufts; /* single malloc for tree space */ + Bytef *window; /* sliding window */ + Bytef *end; /* one byte after sliding window */ + Bytef *read; /* window read pointer */ + Bytef *write; /* window write pointer */ + check_func checkfn; /* check function */ + uLong check; /* check on output */ + +}; + + +/* defines for inflate input/output */ +/* update pointers and return */ +#define UPDBITS {s->bitb=b;s->bitk=k;} +#define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} +#define UPDOUT {s->write=q;} +#define UPDATE {UPDBITS UPDIN UPDOUT} +#define LEAVE {UPDATE return inflate_flush(s,z,r);} +/* get bytes and bits */ +#define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} +#define NEEDBYTE {if(n)r=Z_OK;else LEAVE} +#define NEXTBYTE (n--,*p++) +#define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<<k;k+=8;}} +#define DUMPBITS(j) {b>>=(j);k-=(j);} +/* output bytes */ +#define WAVAIL (uInt)(q<s->read?s->read-q-1:s->end-q) +#define LOADOUT {q=s->write;m=(uInt)WAVAIL;} +#define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=(uInt)WAVAIL;}} +#define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} +#define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;} +#define OUTBYTE(a) {*q++=(Byte)(a);m--;} +/* load local pointers */ +#define LOAD {LOADIN LOADOUT} + +/* masks for lower bits (size given to avoid silly warnings with Visual C++) */ +extern uInt inflate_mask[17]; + +/* copy as much as possible from the sliding window to the output area */ +extern int inflate_flush OF(( + inflate_blocks_statef *, + z_streamp , + int)); + +struct internal_state {int dummy;}; /* for buggy compilers */ + +#endif |