diff options
Diffstat (limited to 'libpng/trees.c')
| -rw-r--r-- | libpng/trees.c | 132 |
1 files changed, 61 insertions, 71 deletions
diff --git a/libpng/trees.c b/libpng/trees.c index f01fb30..6125d6b 100644 --- a/libpng/trees.c +++ b/libpng/trees.c @@ -1,5 +1,5 @@ /* trees.c -- output deflated data using Huffman coding - * Copyright (C) 1995-1998 Jean-loup Gailly + * Copyright (C) 1995-2002 Jean-loup Gailly * For conditions of distribution and use, see copyright notice in zlib.h */ @@ -189,10 +189,7 @@ local void gen_trees_header OF((void)); #ifdef DEBUG local void send_bits OF((deflate_state *s, int value, int length)); -local void send_bits(s, value, length) - deflate_state *s; - int value; /* value to send */ - int length; /* number of bits */ +local void send_bits(deflate_state s, int value, int length) { Tracevv((stderr," l %2d v %4x ", length, value)); Assert(length > 0 && length <= 15, "invalid length"); @@ -236,7 +233,7 @@ local void send_bits(s, value, length) /* =========================================================================== * Initialize the various 'constant' tables. */ -local void tr_static_init() +local void tr_static_init(void) { #if defined(GEN_TREES_H) || !defined(STDC) static int static_init_done = 0; @@ -380,8 +377,7 @@ void gen_trees_header() /* =========================================================================== * Initialize the tree data structures for a new zlib stream. */ -void _tr_init(s) - deflate_state *s; +void _tr_init(deflate_state *s) { tr_static_init(); @@ -409,8 +405,7 @@ void _tr_init(s) /* =========================================================================== * Initialize a new block. */ -local void init_block(s) - deflate_state *s; +local void init_block(deflate_state *s) { int n; /* iterates over tree elements */ @@ -453,10 +448,10 @@ local void init_block(s) * when the heap property is re-established (each father smaller than its * two sons). */ -local void pqdownheap(s, tree, k) - deflate_state *s; - ct_data *tree; /* the tree to restore */ - int k; /* node to move down */ +local void pqdownheap(deflate_state *s, ct_data *tree, int k) + + /* the tree to restore */ + /* node to move down */ { int v = s->heap[k]; int j = k << 1; /* left son of k */ @@ -488,9 +483,9 @@ local void pqdownheap(s, tree, k) * The length opt_len is updated; static_len is also updated if stree is * not null. */ -local void gen_bitlen(s, desc) - deflate_state *s; - tree_desc *desc; /* the tree descriptor */ +local void gen_bitlen(deflate_state *s, tree_desc *desc) + + /* the tree descriptor */ { ct_data *tree = desc->dyn_tree; int max_code = desc->max_code; @@ -575,10 +570,10 @@ local void gen_bitlen(s, desc) * OUT assertion: the field code is set for all tree elements of non * zero code length. */ -local void gen_codes (tree, max_code, bl_count) - ct_data *tree; /* the tree to decorate */ - int max_code; /* largest code with non zero frequency */ - ushf *bl_count; /* number of codes at each bit length */ +local void gen_codes (ct_data *tree, int max_code, ushf *bl_count) + /* the tree to decorate */ + /* largest code with non zero frequency */ + /* number of codes at each bit length */ { ush next_code[MAX_BITS+1]; /* next code value for each bit length */ ush code = 0; /* running code value */ @@ -617,9 +612,9 @@ local void gen_codes (tree, max_code, bl_count) * and corresponding code. The length opt_len is updated; static_len is * also updated if stree is not null. The field max_code is set. */ -local void build_tree(s, desc) - deflate_state *s; - tree_desc *desc; /* the tree descriptor */ +local void build_tree(deflate_state *s, tree_desc *desc) + + /* the tree descriptor */ { ct_data *tree = desc->dyn_tree; const ct_data *stree = desc->stat_desc->static_tree; @@ -704,10 +699,10 @@ local void build_tree(s, desc) * Scan a literal or distance tree to determine the frequencies of the codes * in the bit length tree. */ -local void scan_tree (s, tree, max_code) - deflate_state *s; - ct_data *tree; /* the tree to be scanned */ - int max_code; /* and its largest code of non zero frequency */ +local void scan_tree (deflate_state *s, ct_data *tree, int max_code) + + /* the tree to be scanned */ + /* and its largest code of non zero frequency */ { int n; /* iterates over all tree elements */ int prevlen = -1; /* last emitted length */ @@ -749,10 +744,10 @@ local void scan_tree (s, tree, max_code) * Send a literal or distance tree in compressed form, using the codes in * bl_tree. */ -local void send_tree (s, tree, max_code) - deflate_state *s; - ct_data *tree; /* the tree to be scanned */ - int max_code; /* and its largest code of non zero frequency */ +local void send_tree (deflate_state *s, ct_data *tree, int max_code) + + /* the tree to be scanned */ + /* and its largest code of non zero frequency */ { int n; /* iterates over all tree elements */ int prevlen = -1; /* last emitted length */ @@ -800,8 +795,7 @@ local void send_tree (s, tree, max_code) * Construct the Huffman tree for the bit lengths and return the index in * bl_order of the last bit length code to send. */ -local int build_bl_tree(s) - deflate_state *s; +local int build_bl_tree(deflate_state *s) { int max_blindex; /* index of last bit length code of non zero freq */ @@ -835,9 +829,9 @@ local int build_bl_tree(s) * lengths of the bit length codes, the literal tree and the distance tree. * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. */ -local void send_all_trees(s, lcodes, dcodes, blcodes) - deflate_state *s; - int lcodes, dcodes, blcodes; /* number of codes for each tree */ +local void send_all_trees(deflate_state *s, int lcodes, int dcodes, int blcodes) + + /* number of codes for each tree */ { int rank; /* index in bl_order */ @@ -864,11 +858,11 @@ local void send_all_trees(s, lcodes, dcodes, blcodes) /* =========================================================================== * Send a stored block */ -void _tr_stored_block(s, buf, stored_len, eof) - deflate_state *s; - charf *buf; /* input block */ - ulg stored_len; /* length of input block */ - int eof; /* true if this is the last block for a file */ +void _tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int eof) + + /* input block */ + /* length of input block */ + /* true if this is the last block for a file */ { send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ #ifdef DEBUG @@ -889,8 +883,7 @@ void _tr_stored_block(s, buf, stored_len, eof) * To simplify the code, we assume the worst case of last real code encoded * on one bit only. */ -void _tr_align(s) - deflate_state *s; +void _tr_align(deflate_state *s) { send_bits(s, STATIC_TREES<<1, 3); send_code(s, END_BLOCK, static_ltree); @@ -918,11 +911,11 @@ void _tr_align(s) * Determine the best encoding for the current block: dynamic trees, static * trees or store, and output the encoded block to the zip file. */ -void _tr_flush_block(s, buf, stored_len, eof) - deflate_state *s; - charf *buf; /* input block, or NULL if too old */ - ulg stored_len; /* length of input block */ - int eof; /* true if this is the last block for a file */ +void _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len, int eof) + + /* input block, or NULL if too old */ + /* length of input block */ + /* true if this is the last block for a file */ { ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ int max_blindex = 0; /* index of last bit length code of non zero freq */ @@ -1018,10 +1011,10 @@ void _tr_flush_block(s, buf, stored_len, eof) * Save the match info and tally the frequency counts. Return true if * the current block must be flushed. */ -int _tr_tally (s, dist, lc) - deflate_state *s; - unsigned dist; /* distance of matched string */ - unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ +int _tr_tally (deflate_state *s, unsigned int dist, unsigned int lc) + + /* distance of matched string */ + /* match length-MIN_MATCH or unmatched char (if dist==0) */ { s->d_buf[s->last_lit] = (ush)dist; s->l_buf[s->last_lit++] = (uch)lc; @@ -1068,10 +1061,10 @@ int _tr_tally (s, dist, lc) /* =========================================================================== * Send the block data compressed using the given Huffman trees */ -local void compress_block(s, ltree, dtree) - deflate_state *s; - ct_data *ltree; /* literal tree */ - ct_data *dtree; /* distance tree */ +local void compress_block(deflate_state *s, ct_data *ltree, ct_data *dtree) + + /* literal tree */ + /* distance tree */ { unsigned dist; /* distance of matched string */ int lc; /* match length or unmatched char (if dist == 0) */ @@ -1121,8 +1114,7 @@ local void compress_block(s, ltree, dtree) * IN assertion: the fields freq of dyn_ltree are set and the total of all * frequencies does not exceed 64K (to fit in an int on 16 bit machines). */ -local void set_data_type(s) - deflate_state *s; +local void set_data_type(deflate_state *s) { int n = 0; unsigned ascii_freq = 0; @@ -1138,9 +1130,9 @@ local void set_data_type(s) * method would use a table) * IN assertion: 1 <= len <= 15 */ -local unsigned bi_reverse(code, len) - unsigned code; /* the value to invert */ - int len; /* its bit length */ +local unsigned bi_reverse(unsigned int code, int len) + /* the value to invert */ + /* its bit length */ { register unsigned res = 0; do { @@ -1153,8 +1145,7 @@ local unsigned bi_reverse(code, len) /* =========================================================================== * Flush the bit buffer, keeping at most 7 bits in it. */ -local void bi_flush(s) - deflate_state *s; +local void bi_flush(deflate_state *s) { if (s->bi_valid == 16) { put_short(s, s->bi_buf); @@ -1170,8 +1161,7 @@ local void bi_flush(s) /* =========================================================================== * Flush the bit buffer and align the output on a byte boundary */ -local void bi_windup(s) - deflate_state *s; +local void bi_windup(deflate_state *s) { if (s->bi_valid > 8) { put_short(s, s->bi_buf); @@ -1189,11 +1179,11 @@ local void bi_windup(s) * Copy a stored block, storing first the length and its * one's complement if requested. */ -local void copy_block(s, buf, len, header) - deflate_state *s; - charf *buf; /* the input data */ - unsigned len; /* its length */ - int header; /* true if block header must be written */ +local void copy_block(deflate_state *s, charf *buf, unsigned int len, int header) + + /* the input data */ + /* its length */ + /* true if block header must be written */ { bi_windup(s); /* align on byte boundary */ s->last_eob_len = 8; /* enough lookahead for inflate */ |