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diff --git a/raylib/src/external/sdefl.h b/raylib/src/external/sdefl.h
new file mode 100644
index 0000000..36015b9
--- /dev/null
+++ b/raylib/src/external/sdefl.h
@@ -0,0 +1,790 @@
+/*# Small Deflate
+`sdefl` is a small bare bone lossless compression library in ANSI C (ISO C90)
+which implements the Deflate (RFC 1951) compressed data format specification standard.
+It is mainly tuned to get as much speed and compression ratio from as little code
+as needed to keep the implementation as concise as possible.
+
+## Features
+- Portable single header and source file duo written in ANSI C (ISO C90)
+- Dual license with either MIT or public domain
+- Small implementation
+    - Deflate: 525 LoC
+    - Inflate: 320 LoC
+- Webassembly:
+    - Deflate ~3.7 KB (~2.2KB compressed)
+    - Inflate ~3.6 KB (~2.2KB compressed)
+
+## Usage:
+This file behaves differently depending on what symbols you define
+before including it.
+
+Header-File mode:
+If you do not define `SDEFL_IMPLEMENTATION` before including this file, it
+will operate in header only mode. In this mode it declares all used structs
+and the API of the library without including the implementation of the library.
+
+Implementation mode:
+If you define `SDEFL_IMPLEMENTATION` before including this file, it will
+compile the implementation . Make sure that you only include
+this file implementation in *one* C or C++ file to prevent collisions.
+
+### Benchmark
+
+| Compressor name         | Compression| Decompress.| Compr. size | Ratio |
+| ------------------------| -----------| -----------| ----------- | ----- |
+| miniz 1.0 -1            |   122 MB/s |   208 MB/s |    48510028 | 48.51 |
+| miniz 1.0 -6            |    27 MB/s |   260 MB/s |    36513697 | 36.51 |
+| miniz 1.0 -9            |    23 MB/s |   261 MB/s |    36460101 | 36.46 |
+| zlib 1.2.11 -1          |    72 MB/s |   307 MB/s |    42298774 | 42.30 |
+| zlib 1.2.11 -6          |    24 MB/s |   313 MB/s |    36548921 | 36.55 |
+| zlib 1.2.11 -9          |    20 MB/s |   314 MB/s |    36475792 | 36.48 |
+| sdefl 1.0 -0            |   127 MB/s |   355 MB/s |    40004116 | 39.88 |
+| sdefl 1.0 -1            |   111 MB/s |   413 MB/s |    38940674 | 38.82 |
+| sdefl 1.0 -5            |    45 MB/s |   436 MB/s |    36577183 | 36.46 |
+| sdefl 1.0 -7            |    38 MB/s |   432 MB/s |    36523781 | 36.41 |
+| libdeflate 1.3 -1       |   147 MB/s |   667 MB/s |    39597378 | 39.60 |
+| libdeflate 1.3 -6       |    69 MB/s |   689 MB/s |    36648318 | 36.65 |
+| libdeflate 1.3 -9       |    13 MB/s |   672 MB/s |    35197141 | 35.20 |
+| libdeflate 1.3 -12      |  8.13 MB/s |   670 MB/s |    35100568 | 35.10 |
+
+### Compression
+Results on the [Silesia compression corpus](http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia):
+
+| File    |   Original | `sdefl 0`    | `sdefl 5`  | `sdefl 7`   |
+| --------| -----------| -------------| ---------- | ------------|
+| dickens | 10.192.446 | 4,260,187    |  3,845,261 |   3,833,657 |
+| mozilla | 51.220.480 | 20,774,706   | 19,607,009 |  19,565,867 |
+| mr      |  9.970.564 | 3,860,531    |  3,673,460 |   3,665,627 |
+| nci     | 33.553.445 | 4,030,283    |  3,094,526 |   3,006,075 |
+| ooffice |  6.152.192 | 3,320,063    |  3,186,373 |   3,183,815 |
+| osdb    | 10.085.684 | 3,919,646    |  3,649,510 |   3,649,477 |
+| reymont |  6.627.202 | 2,263,378    |  1,857,588 |   1,827,237 |
+| samba   | 21.606.400 | 6,121,797    |  5,462,670 |   5,450,762 |
+| sao     |  7.251.944 | 5,612,421    |  5,485,380 |   5,481,765 |
+| webster | 41.458.703 | 13,972,648   | 12,059,432 |  11,991,421 |
+| xml     |  5.345.280 | 886,620      |    674,009 |     662,141 |
+| x-ray   |  8.474.240 | 6,304,655    |  6,244,779 |   6,244,779 |
+
+## License
+```
+------------------------------------------------------------------------------
+This software is available under 2 licenses -- choose whichever you prefer.
+------------------------------------------------------------------------------
+ALTERNATIVE A - MIT License
+Copyright (c) 2020-2023 Micha Mettke
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+------------------------------------------------------------------------------
+ALTERNATIVE B - Public Domain (www.unlicense.org)
+This is free and unencumbered software released into the public domain.
+Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
+software, either in source code form or as a compiled binary, for any purpose,
+commercial or non-commercial, and by any means.
+In jurisdictions that recognize copyright laws, the author or authors of this
+software dedicate any and all copyright interest in the software to the public
+domain. We make this dedication for the benefit of the public at large and to
+the detriment of our heirs and successors. We intend this dedication to be an
+overt act of relinquishment in perpetuity of all present and future rights to
+this software under copyright law.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+------------------------------------------------------------------------------
+```
+*/
+#ifndef SDEFL_H_INCLUDED
+#define SDEFL_H_INCLUDED
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define SDEFL_MAX_OFF   (1 << 15)
+#define SDEFL_WIN_SIZ   SDEFL_MAX_OFF
+#define SDEFL_WIN_MSK   (SDEFL_WIN_SIZ-1)
+
+#define SDEFL_HASH_BITS 15
+#define SDEFL_HASH_SIZ  (1 << SDEFL_HASH_BITS)
+#define SDEFL_HASH_MSK  (SDEFL_HASH_SIZ-1)
+
+#define SDEFL_MIN_MATCH 4
+#define SDEFL_BLK_MAX   (256*1024)
+#define SDEFL_SEQ_SIZ   ((SDEFL_BLK_MAX+2)/3)
+
+#define SDEFL_SYM_MAX   (288)
+#define SDEFL_OFF_MAX   (32)
+#define SDEFL_PRE_MAX   (19)
+
+#define SDEFL_LVL_MIN   0
+#define SDEFL_LVL_DEF   5
+#define SDEFL_LVL_MAX   8
+
+struct sdefl_freq {
+  unsigned lit[SDEFL_SYM_MAX];
+  unsigned off[SDEFL_OFF_MAX];
+};
+struct sdefl_code_words {
+  unsigned lit[SDEFL_SYM_MAX];
+  unsigned off[SDEFL_OFF_MAX];
+};
+struct sdefl_lens {
+  unsigned char lit[SDEFL_SYM_MAX];
+  unsigned char off[SDEFL_OFF_MAX];
+};
+struct sdefl_codes {
+  struct sdefl_code_words word;
+  struct sdefl_lens len;
+};
+struct sdefl_seqt {
+  int off, len;
+};
+struct sdefl {
+  int bits, bitcnt;
+  int tbl[SDEFL_HASH_SIZ];
+  int prv[SDEFL_WIN_SIZ];
+
+  int seq_cnt;
+  struct sdefl_seqt seq[SDEFL_SEQ_SIZ];
+  struct sdefl_freq freq;
+  struct sdefl_codes cod;
+};
+extern int sdefl_bound(int in_len);
+extern int sdeflate(struct sdefl *s, void *o, const void *i, int n, int lvl);
+extern int zsdeflate(struct sdefl *s, void *o, const void *i, int n, int lvl);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* SDEFL_H_INCLUDED */
+
+#ifdef SDEFL_IMPLEMENTATION
+
+#include <assert.h> /* assert */
+#include <string.h> /* memcpy */
+#include <limits.h> /* CHAR_BIT */
+
+#define SDEFL_NIL               (-1)
+#define SDEFL_MAX_MATCH         258
+#define SDEFL_MAX_CODE_LEN      (15)
+#define SDEFL_SYM_BITS          (10u)
+#define SDEFL_SYM_MSK           ((1u << SDEFL_SYM_BITS)-1u)
+#define SDEFL_RAW_BLK_SIZE      (65535)
+#define SDEFL_LIT_LEN_CODES     (14)
+#define SDEFL_OFF_CODES         (15)
+#define SDEFL_PRE_CODES         (7)
+#define SDEFL_CNT_NUM(n)        ((((n)+3u/4u)+3u)&~3u)
+#define SDEFL_EOB               (256)
+
+#define sdefl_npow2(n) (1 << (sdefl_ilog2((n)-1) + 1))
+#define sdefl_div_round_up(n,d) (((n)+((d)-1))/(d))
+
+static int
+sdefl_ilog2(int n) {
+  if (!n) return 0;
+#ifdef _MSC_VER
+  unsigned long msbp = 0;
+  _BitScanReverse(&msbp, (unsigned long)n);
+  return (int)msbp;
+#elif defined(__GNUC__) || defined(__clang__)
+  return (int)sizeof(unsigned long) * CHAR_BIT - 1 - __builtin_clzl((unsigned long)n);
+#else
+  #define lt(n) n, n, n, n, n, n, n, n, n, n, n, n, n, n, n, n
+  static const char tbl[256] = {
+    0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,lt(4), lt(5), lt(5), lt(6), lt(6), lt(6), lt(6),
+    lt(7), lt(7), lt(7), lt(7), lt(7), lt(7), lt(7), lt(7)};
+  int tt, t;
+  if ((tt = (n >> 16))) {
+    return (t = (tt >> 8)) ? 24 + tbl[t] : 16 + tbl[tt];
+  } else {
+    return (t = (n >> 8)) ? 8 + tbl[t] : tbl[n];
+  }
+  #undef lt
+#endif
+}
+static unsigned
+sdefl_uload32(const void *p) {
+  /* hopefully will be optimized to an unaligned read */
+  unsigned n = 0;
+  memcpy(&n, p, sizeof(n));
+  return n;
+}
+static unsigned
+sdefl_hash32(const void *p) {
+  unsigned n = sdefl_uload32(p);
+  return (n * 0x9E377989) >> (32 - SDEFL_HASH_BITS);
+}
+static void
+sdefl_put(unsigned char **dst, struct sdefl *s, int code, int bitcnt) {
+  s->bits |= (code << s->bitcnt);
+  s->bitcnt += bitcnt;
+  while (s->bitcnt >= 8) {
+    unsigned char *tar = *dst;
+    *tar = (unsigned char)(s->bits & 0xFF);
+    s->bits >>= 8;
+    s->bitcnt -= 8;
+    *dst = *dst + 1;
+  }
+}
+static void
+sdefl_heap_sub(unsigned A[], unsigned len, unsigned sub) {
+  unsigned c, p = sub;
+  unsigned v = A[sub];
+  while ((c = p << 1) <= len) {
+    if (c < len && A[c + 1] > A[c]) c++;
+    if (v >= A[c]) break;
+    A[p] = A[c], p = c;
+  }
+  A[p] = v;
+}
+static void
+sdefl_heap_array(unsigned *A, unsigned len) {
+  unsigned sub;
+  for (sub = len >> 1; sub >= 1; sub--)
+    sdefl_heap_sub(A, len, sub);
+}
+static void
+sdefl_heap_sort(unsigned *A, unsigned n) {
+  A--;
+  sdefl_heap_array(A, n);
+  while (n >= 2) {
+    unsigned tmp = A[n];
+    A[n--] = A[1];
+    A[1] = tmp;
+    sdefl_heap_sub(A, n, 1);
+  }
+}
+static unsigned
+sdefl_sort_sym(unsigned sym_cnt, unsigned *freqs,
+               unsigned char *lens, unsigned *sym_out) {
+  unsigned cnts[SDEFL_CNT_NUM(SDEFL_SYM_MAX)] = {0};
+  unsigned cnt_num = SDEFL_CNT_NUM(sym_cnt);
+  unsigned used_sym = 0;
+  unsigned sym, i;
+  for (sym = 0; sym < sym_cnt; sym++)
+    cnts[freqs[sym] < cnt_num-1 ? freqs[sym]: cnt_num-1]++;
+  for (i = 1; i < cnt_num; i++) {
+    unsigned cnt = cnts[i];
+    cnts[i] = used_sym;
+    used_sym += cnt;
+  }
+  for (sym = 0; sym < sym_cnt; sym++) {
+    unsigned freq = freqs[sym];
+    if (freq) {
+        unsigned idx = freq < cnt_num-1 ? freq : cnt_num-1;
+        sym_out[cnts[idx]++] = sym | (freq << SDEFL_SYM_BITS);
+    } else lens[sym] = 0;
+  }
+  sdefl_heap_sort(sym_out + cnts[cnt_num-2], cnts[cnt_num-1] - cnts[cnt_num-2]);
+  return used_sym;
+}
+static void
+sdefl_build_tree(unsigned *A, unsigned sym_cnt) {
+  unsigned i = 0, b = 0, e = 0;
+  do {
+    unsigned m, n, freq_shift;
+    if (i != sym_cnt && (b == e || (A[i] >> SDEFL_SYM_BITS) <= (A[b] >> SDEFL_SYM_BITS)))
+      m = i++;
+    else m = b++;
+    if (i != sym_cnt && (b == e || (A[i] >> SDEFL_SYM_BITS) <= (A[b] >> SDEFL_SYM_BITS)))
+      n = i++;
+    else n = b++;
+
+    freq_shift = (A[m] & ~SDEFL_SYM_MSK) + (A[n] & ~SDEFL_SYM_MSK);
+    A[m] = (A[m] & SDEFL_SYM_MSK) | (e << SDEFL_SYM_BITS);
+    A[n] = (A[n] & SDEFL_SYM_MSK) | (e << SDEFL_SYM_BITS);
+    A[e] = (A[e] & SDEFL_SYM_MSK) | freq_shift;
+  } while (sym_cnt - ++e > 1);
+}
+static void
+sdefl_gen_len_cnt(unsigned *A, unsigned root, unsigned *len_cnt,
+                  unsigned max_code_len) {
+  int n;
+  unsigned i;
+  for (i = 0; i <= max_code_len; i++)
+    len_cnt[i] = 0;
+  len_cnt[1] = 2;
+
+  A[root] &= SDEFL_SYM_MSK;
+  for (n = (int)root - 1; n >= 0; n--) {
+    unsigned p = A[n] >> SDEFL_SYM_BITS;
+    unsigned pdepth = A[p] >> SDEFL_SYM_BITS;
+    unsigned depth = pdepth + 1;
+    unsigned len = depth;
+
+    A[n] = (A[n] & SDEFL_SYM_MSK) | (depth << SDEFL_SYM_BITS);
+    if (len >= max_code_len) {
+      len = max_code_len;
+      do len--; while (!len_cnt[len]);
+    }
+    len_cnt[len]--;
+    len_cnt[len+1] += 2;
+  }
+}
+static void
+sdefl_gen_codes(unsigned *A, unsigned char *lens, const unsigned *len_cnt,
+                unsigned max_code_word_len, unsigned sym_cnt) {
+  unsigned i, sym, len, nxt[SDEFL_MAX_CODE_LEN + 1];
+  for (i = 0, len = max_code_word_len; len >= 1; len--) {
+    unsigned cnt = len_cnt[len];
+    while (cnt--) lens[A[i++] & SDEFL_SYM_MSK] = (unsigned char)len;
+  }
+  nxt[0] = nxt[1] = 0;
+  for (len = 2; len <= max_code_word_len; len++)
+    nxt[len] = (nxt[len-1] + len_cnt[len-1]) << 1;
+  for (sym = 0; sym < sym_cnt; sym++)
+    A[sym] = nxt[lens[sym]]++;
+}
+static unsigned
+sdefl_rev(unsigned c, unsigned char n) {
+  c = ((c & 0x5555) << 1) | ((c & 0xAAAA) >> 1);
+  c = ((c & 0x3333) << 2) | ((c & 0xCCCC) >> 2);
+  c = ((c & 0x0F0F) << 4) | ((c & 0xF0F0) >> 4);
+  c = ((c & 0x00FF) << 8) | ((c & 0xFF00) >> 8);
+  return c >> (16-n);
+}
+static void
+sdefl_huff(unsigned char *lens, unsigned *codes, unsigned *freqs,
+           unsigned num_syms, unsigned max_code_len) {
+  unsigned c, *A = codes;
+  unsigned len_cnt[SDEFL_MAX_CODE_LEN + 1];
+  unsigned used_syms = sdefl_sort_sym(num_syms, freqs, lens, A);
+  if (!used_syms) return;
+  if (used_syms == 1) {
+    unsigned s = A[0] & SDEFL_SYM_MSK;
+    unsigned i = s ? s : 1;
+    codes[0] = 0, lens[0] = 1;
+    codes[i] = 1, lens[i] = 1;
+    return;
+  }
+  sdefl_build_tree(A, used_syms);
+  sdefl_gen_len_cnt(A, used_syms-2, len_cnt, max_code_len);
+  sdefl_gen_codes(A, lens, len_cnt, max_code_len, num_syms);
+  for (c = 0; c < num_syms; c++) {
+    codes[c] = sdefl_rev(codes[c], lens[c]);
+  }
+}
+struct sdefl_symcnt {
+  int items;
+  int lit;
+  int off;
+};
+static void
+sdefl_precode(struct sdefl_symcnt *cnt, unsigned *freqs, unsigned *items,
+              const unsigned char *litlen, const unsigned char *offlen) {
+  unsigned *at = items;
+  unsigned run_start = 0;
+
+  unsigned total = 0;
+  unsigned char lens[SDEFL_SYM_MAX + SDEFL_OFF_MAX];
+  for (cnt->lit = SDEFL_SYM_MAX; cnt->lit > 257; cnt->lit--)
+    if (litlen[cnt->lit - 1]) break;
+  for (cnt->off = SDEFL_OFF_MAX; cnt->off > 1; cnt->off--)
+    if (offlen[cnt->off - 1]) break;
+
+  total = (unsigned)(cnt->lit + cnt->off);
+  memcpy(lens, litlen, sizeof(unsigned char) * (size_t)cnt->lit);
+  memcpy(lens + cnt->lit, offlen, sizeof(unsigned char) * (size_t)cnt->off);
+  do {
+    unsigned len = lens[run_start];
+    unsigned run_end = run_start;
+    do run_end++; while (run_end != total && len == lens[run_end]);
+    if (!len) {
+      while ((run_end - run_start) >= 11) {
+        unsigned n = (run_end - run_start) - 11;
+        unsigned xbits =  n < 0x7f ? n : 0x7f;
+        freqs[18]++;
+        *at++ = 18u | (xbits << 5u);
+        run_start += 11 + xbits;
+      }
+      if ((run_end - run_start) >= 3) {
+        unsigned n = (run_end - run_start) - 3;
+        unsigned xbits =  n < 0x7 ? n : 0x7;
+        freqs[17]++;
+        *at++ = 17u | (xbits << 5u);
+        run_start += 3 + xbits;
+      }
+    } else if ((run_end - run_start) >= 4) {
+      freqs[len]++;
+      *at++ = len;
+      run_start++;
+      do {
+        unsigned xbits = (run_end - run_start) - 3;
+        xbits = xbits < 0x03 ? xbits : 0x03;
+        *at++ = 16 | (xbits << 5);
+        run_start += 3 + xbits;
+        freqs[16]++;
+      } while ((run_end - run_start) >= 3);
+    }
+    while (run_start != run_end) {
+      freqs[len]++;
+      *at++ = len;
+      run_start++;
+    }
+  } while (run_start != total);
+  cnt->items = (int)(at - items);
+}
+struct sdefl_match_codest {
+  int ls, lc;
+  int dc, dx;
+};
+static void
+sdefl_match_codes(struct sdefl_match_codest *cod, int dist, int len) {
+  static const short dxmax[] = {0,6,12,24,48,96,192,384,768,1536,3072,6144,12288,24576};
+  static const unsigned char lslot[258+1] = {
+    0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 12,
+    12, 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 16,
+    16, 16, 16, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18,
+    18, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 20, 20, 20,
+    20, 20, 20, 20, 20, 20, 20, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
+    21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
+    22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
+    23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
+    24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 25, 25, 25,
+    25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
+    25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26,
+    26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
+    26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+    27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+    27, 27, 28
+  };
+  assert(len <= 258);
+  assert(dist <= 32768);
+  cod->ls = lslot[len];
+  cod->lc = 257 + cod->ls;
+  assert(cod->lc <= 285);
+
+  cod->dx = sdefl_ilog2(sdefl_npow2(dist) >> 2);
+  cod->dc = cod->dx ? ((cod->dx + 1) << 1) + (dist > dxmax[cod->dx]) : dist-1;
+}
+enum sdefl_blk_type {
+  SDEFL_BLK_UCOMPR,
+  SDEFL_BLK_DYN
+};
+static enum sdefl_blk_type
+sdefl_blk_type(const struct sdefl *s, int blk_len, int pre_item_len,
+               const unsigned *pre_freq, const unsigned char *pre_len) {
+  static const unsigned char x_pre_bits[] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
+  static const unsigned char x_len_bits[] = {0,0,0,0,0,0,0,0, 1,1,1,1,2,2,2,2,
+    3,3,3,3,4,4,4,4, 5,5,5,5,0};
+  static const unsigned char x_off_bits[] = {0,0,0,0,1,1,2,2, 3,3,4,4,5,5,6,6,
+    7,7,8,8,9,9,10,10, 11,11,12,12,13,13};
+
+  int dyn_cost = 0;
+  int fix_cost = 0;
+  int sym = 0;
+
+  dyn_cost += 5 + 5 + 4 + (3 * pre_item_len);
+  for (sym = 0; sym < SDEFL_PRE_MAX; sym++)
+    dyn_cost += pre_freq[sym] * (x_pre_bits[sym] + pre_len[sym]);
+  for (sym = 0; sym < 256; sym++)
+    dyn_cost += s->freq.lit[sym] * s->cod.len.lit[sym];
+  dyn_cost += s->cod.len.lit[SDEFL_EOB];
+  for (sym = 257; sym < 286; sym++)
+    dyn_cost += s->freq.lit[sym] * (x_len_bits[sym - 257] + s->cod.len.lit[sym]);
+  for (sym = 0; sym < 30; sym++)
+    dyn_cost += s->freq.off[sym] * (x_off_bits[sym] + s->cod.len.off[sym]);
+
+  fix_cost += 8*(5 * sdefl_div_round_up(blk_len, SDEFL_RAW_BLK_SIZE) + blk_len + 1 + 2);
+  return (dyn_cost < fix_cost) ? SDEFL_BLK_DYN : SDEFL_BLK_UCOMPR;
+}
+static void
+sdefl_put16(unsigned char **dst, unsigned short x) {
+  unsigned char *val = *dst;
+  val[0] = (unsigned char)(x & 0xff);
+  val[1] = (unsigned char)(x >> 8);
+  *dst = val + 2;
+}
+static void
+sdefl_match(unsigned char **dst, struct sdefl *s, int dist, int len) {
+  static const char lxn[] = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0};
+  static const short lmin[] = {3,4,5,6,7,8,9,10,11,13,15,17,19,23,27,31,35,43,
+      51,59,67,83,99,115,131,163,195,227,258};
+  static const short dmin[] = {1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,257,
+      385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577};
+
+  struct sdefl_match_codest cod;
+  sdefl_match_codes(&cod, dist, len);
+  sdefl_put(dst, s, (int)s->cod.word.lit[cod.lc], s->cod.len.lit[cod.lc]);
+  sdefl_put(dst, s, len - lmin[cod.ls], lxn[cod.ls]);
+  sdefl_put(dst, s, (int)s->cod.word.off[cod.dc], s->cod.len.off[cod.dc]);
+  sdefl_put(dst, s, dist - dmin[cod.dc], cod.dx);
+}
+static void
+sdefl_flush(unsigned char **dst, struct sdefl *s, int is_last,
+            const unsigned char *in, int blk_begin, int blk_end) {
+  int blk_len = blk_end - blk_begin;
+  int j, i = 0, item_cnt = 0;
+  struct sdefl_symcnt symcnt = {0};
+  unsigned codes[SDEFL_PRE_MAX];
+  unsigned char lens[SDEFL_PRE_MAX];
+  unsigned freqs[SDEFL_PRE_MAX] = {0};
+  unsigned items[SDEFL_SYM_MAX + SDEFL_OFF_MAX];
+  static const unsigned char perm[SDEFL_PRE_MAX] = {16,17,18,0,8,7,9,6,10,5,11,
+      4,12,3,13,2,14,1,15};
+
+  /* calculate huffman codes */
+  s->freq.lit[SDEFL_EOB]++;
+  sdefl_huff(s->cod.len.lit, s->cod.word.lit, s->freq.lit, SDEFL_SYM_MAX, SDEFL_LIT_LEN_CODES);
+  sdefl_huff(s->cod.len.off, s->cod.word.off, s->freq.off, SDEFL_OFF_MAX, SDEFL_OFF_CODES);
+  sdefl_precode(&symcnt, freqs, items, s->cod.len.lit, s->cod.len.off);
+  sdefl_huff(lens, codes, freqs, SDEFL_PRE_MAX, SDEFL_PRE_CODES);
+  for (item_cnt = SDEFL_PRE_MAX; item_cnt > 4; item_cnt--) {
+    if (lens[perm[item_cnt - 1]]){
+      break;
+    }
+  }
+  /* write block */
+  switch (sdefl_blk_type(s, blk_len, item_cnt, freqs, lens)) {
+  case SDEFL_BLK_UCOMPR: {
+    /* uncompressed blocks */
+    int n = sdefl_div_round_up(blk_len, SDEFL_RAW_BLK_SIZE);
+    for (i = 0; i < n; ++i) {
+      int fin = is_last && (i + 1 == n);
+      int amount = blk_len < SDEFL_RAW_BLK_SIZE ? blk_len : SDEFL_RAW_BLK_SIZE;
+      sdefl_put(dst, s, !!fin, 1); /* block */
+      sdefl_put(dst, s, 0x00, 2); /* stored block */
+      if (s->bitcnt) {
+        sdefl_put(dst, s, 0x00, 8 - s->bitcnt);
+      }
+      assert(s->bitcnt == 0);
+      sdefl_put16(dst, (unsigned short)amount);
+      sdefl_put16(dst, ~(unsigned short)amount);
+      memcpy(*dst, in + blk_begin + i * SDEFL_RAW_BLK_SIZE, amount);
+      *dst = *dst + amount;
+      blk_len -= amount;
+    }
+  } break;
+  case SDEFL_BLK_DYN: {
+    /* dynamic huffman block */
+    sdefl_put(dst, s, !!is_last, 1); /* block */
+    sdefl_put(dst, s, 0x02, 2); /* dynamic huffman */
+    sdefl_put(dst, s, symcnt.lit - 257, 5);
+    sdefl_put(dst, s, symcnt.off - 1, 5);
+    sdefl_put(dst, s, item_cnt - 4, 4);
+    for (i = 0; i < item_cnt; ++i) {
+      sdefl_put(dst, s, lens[perm[i]], 3);
+    }
+    for (i = 0; i < symcnt.items; ++i) {
+      unsigned sym = items[i] & 0x1F;
+      sdefl_put(dst, s, (int)codes[sym], lens[sym]);
+      if (sym < 16) continue;
+      if (sym == 16) sdefl_put(dst, s, items[i] >> 5, 2);
+      else if(sym == 17) sdefl_put(dst, s, items[i] >> 5, 3);
+      else sdefl_put(dst, s, items[i] >> 5, 7);
+    }
+    /* block sequences */
+    for (i = 0; i < s->seq_cnt; ++i) {
+      if (s->seq[i].off >= 0) {
+        for (j = 0; j < s->seq[i].len; ++j) {
+          int c = in[s->seq[i].off + j];
+          sdefl_put(dst, s, (int)s->cod.word.lit[c], s->cod.len.lit[c]);
+        }
+      } else {
+        sdefl_match(dst, s, -s->seq[i].off, s->seq[i].len);
+      }
+    }
+    sdefl_put(dst, s, (int)(s)->cod.word.lit[SDEFL_EOB], (s)->cod.len.lit[SDEFL_EOB]);
+  } break;}
+  memset(&s->freq, 0, sizeof(s->freq));
+  s->seq_cnt = 0;
+}
+static void
+sdefl_seq(struct sdefl *s, int off, int len) {
+  assert(s->seq_cnt + 2 < SDEFL_SEQ_SIZ);
+  s->seq[s->seq_cnt].off = off;
+  s->seq[s->seq_cnt].len = len;
+  s->seq_cnt++;
+}
+static void
+sdefl_reg_match(struct sdefl *s, int off, int len) {
+  struct sdefl_match_codest cod;
+  sdefl_match_codes(&cod, off, len);
+
+  assert(cod.lc < SDEFL_SYM_MAX);
+  assert(cod.dc < SDEFL_OFF_MAX);
+
+  s->freq.lit[cod.lc]++;
+  s->freq.off[cod.dc]++;
+}
+struct sdefl_match {
+  int off;
+  int len;
+};
+static void
+sdefl_fnd(struct sdefl_match *m, const struct sdefl *s, int chain_len,
+          int max_match, const unsigned char *in, int p, int e) {
+  int i = s->tbl[sdefl_hash32(in + p)];
+  int limit = ((p - SDEFL_WIN_SIZ) < SDEFL_NIL) ? SDEFL_NIL : (p-SDEFL_WIN_SIZ);
+
+  assert(p < e);
+  assert(p + max_match <= e);
+  while (i > limit) {
+    assert(i + m->len < e);
+    assert(p + m->len < e);
+    assert(i + SDEFL_MIN_MATCH < e);
+    assert(p + SDEFL_MIN_MATCH < e);
+
+    if (in[i + m->len] == in[p + m->len] &&
+      (sdefl_uload32(&in[i]) == sdefl_uload32(&in[p]))) {
+      int n = SDEFL_MIN_MATCH;
+      while (n < max_match && in[i + n] == in[p + n]) {
+        assert(i + n < e);
+        assert(p + n < e);
+        n++;
+      }
+      if (n > m->len) {
+        m->len = n, m->off = p - i;
+        if (n == max_match)
+          break;
+      }
+    }
+    if (!(--chain_len)) break;
+    i = s->prv[i & SDEFL_WIN_MSK];
+  }
+}
+static int
+sdefl_compr(struct sdefl *s, unsigned char *out, const unsigned char *in,
+            int in_len, int lvl) {
+  unsigned char *q = out;
+  static const unsigned char pref[] = {8,10,14,24,30,48,65,96,130};
+  int max_chain = (lvl < 8) ? (1 << (lvl + 1)): (1 << 13);
+  int n, i = 0, litlen = 0;
+  for (n = 0; n < SDEFL_HASH_SIZ; ++n) {
+    s->tbl[n] = SDEFL_NIL;
+  }
+  do {int blk_begin = i;
+    int blk_end = ((i + SDEFL_BLK_MAX) < in_len) ? (i + SDEFL_BLK_MAX) : in_len;
+    while (i < blk_end) {
+      struct sdefl_match m = {0};
+      int left = blk_end - i;
+      int max_match = (left > SDEFL_MAX_MATCH) ? SDEFL_MAX_MATCH : left;
+      int nice_match = pref[lvl] < max_match ? pref[lvl] : max_match;
+      int run = 1, inc = 1, run_inc = 0;
+      if (max_match > SDEFL_MIN_MATCH) {
+        sdefl_fnd(&m, s, max_chain, max_match, in, i, in_len);
+      }
+      if (lvl >= 5 && m.len >= SDEFL_MIN_MATCH && m.len + 1 < nice_match){
+        struct sdefl_match m2 = {0};
+        sdefl_fnd(&m2, s, max_chain, m.len + 1, in, i + 1, in_len);
+        m.len = (m2.len > m.len) ? 0 : m.len;
+      }
+      if (m.len >= SDEFL_MIN_MATCH) {
+        if (litlen) {
+          sdefl_seq(s, i - litlen, litlen);
+          litlen = 0;
+        }
+        sdefl_seq(s, -m.off, m.len);
+        sdefl_reg_match(s, m.off, m.len);
+        if (lvl < 2 && m.len >= nice_match) {
+          inc = m.len;
+        } else {
+          run = m.len;
+        }
+      } else {
+        s->freq.lit[in[i]]++;
+        litlen++;
+      }
+      run_inc = run * inc;
+      if (in_len - (i + run_inc) > SDEFL_MIN_MATCH) {
+        while (run-- > 0) {
+          unsigned h = sdefl_hash32(&in[i]);
+          s->prv[i&SDEFL_WIN_MSK] = s->tbl[h];
+          s->tbl[h] = i, i += inc;
+          assert(i <= blk_end);
+        }
+      } else {
+        i += run_inc;
+        assert(i <= blk_end);
+      }
+    }
+    if (litlen) {
+      sdefl_seq(s, i - litlen, litlen);
+      litlen = 0;
+    }
+    sdefl_flush(&q, s, blk_end == in_len, in, blk_begin, blk_end);
+  } while (i < in_len);
+  if (s->bitcnt) {
+    sdefl_put(&q, s, 0x00, 8 - s->bitcnt);
+  }
+  assert(s->bitcnt == 0);
+  return (int)(q - out);
+}
+extern int
+sdeflate(struct sdefl *s, void *out, const void *in, int n, int lvl) {
+  s->bits = s->bitcnt = 0;
+  return sdefl_compr(s, (unsigned char*)out, (const unsigned char*)in, n, lvl);
+}
+static unsigned
+sdefl_adler32(unsigned adler32, const unsigned char *in, int in_len) {
+  #define SDEFL_ADLER_INIT (1)
+  const unsigned ADLER_MOD = 65521;
+  unsigned s1 = adler32 & 0xffff;
+  unsigned s2 = adler32 >> 16;
+  unsigned blk_len, i;
+
+  blk_len = in_len % 5552;
+  while (in_len) {
+    for (i = 0; i + 7 < blk_len; i += 8) {
+      s1 += in[0]; s2 += s1;
+      s1 += in[1]; s2 += s1;
+      s1 += in[2]; s2 += s1;
+      s1 += in[3]; s2 += s1;
+      s1 += in[4]; s2 += s1;
+      s1 += in[5]; s2 += s1;
+      s1 += in[6]; s2 += s1;
+      s1 += in[7]; s2 += s1;
+      in += 8;
+    }
+    for (; i < blk_len; ++i) {
+      s1 += *in++, s2 += s1;
+    }
+    s1 %= ADLER_MOD;
+    s2 %= ADLER_MOD;
+    in_len -= blk_len;
+    blk_len = 5552;
+  }
+  return (unsigned)(s2 << 16) + (unsigned)s1;
+}
+extern int
+zsdeflate(struct sdefl *s, void *out, const void *in, int n, int lvl) {
+  int p = 0;
+  unsigned a = 0;
+  unsigned char *q = (unsigned char*)out;
+
+  s->bits = s->bitcnt = 0;
+  sdefl_put(&q, s, 0x78, 8); /* deflate, 32k window */
+  sdefl_put(&q, s, 0x01, 8); /* fast compression */
+  q += sdefl_compr(s, q, (const unsigned char*)in, n, lvl);
+
+  /* append adler checksum */
+  a = sdefl_adler32(SDEFL_ADLER_INIT, (const unsigned char*)in, n);
+  for (p = 0; p < 4; ++p) {
+    sdefl_put(&q, s, (a >> 24) & 0xFF, 8);
+    a <<= 8;
+  }
+  return (int)(q - (unsigned char*)out);
+}
+extern int
+sdefl_bound(int len) {
+  int max_blocks = 1 + sdefl_div_round_up(len, SDEFL_RAW_BLK_SIZE);
+  int bound = 5 * max_blocks + len + 1 + 4 + 8;
+  return bound;
+}
+#endif /* SDEFL_IMPLEMENTATION */