thirdparty-miniz/miniz_tdef.h

#pragma once
#include "miniz_common.h"

// ------------------- Low-level Compression API Definitions

// Set TDEFL_LESS_MEMORY to 1 to use less memory (compression will be slightly slower, and raw/dynamic blocks will be output more frequently).
#define TDEFL_LESS_MEMORY 0

// tdefl_init() compression flags logically OR'd together (low 12 bits contain the max. number of probes per dictionary search):
// TDEFL_DEFAULT_MAX_PROBES: The compressor defaults to 128 dictionary probes per dictionary search. 0=Huffman only, 1=Huffman+LZ (fastest/crap compression), 4095=Huffman+LZ (slowest/best compression).
enum
{
    TDEFL_HUFFMAN_ONLY = 0,
    TDEFL_DEFAULT_MAX_PROBES = 128,
    TDEFL_MAX_PROBES_MASK = 0xFFF
};

// TDEFL_WRITE_ZLIB_HEADER: If set, the compressor outputs a zlib header before the deflate data, and the Adler-32 of the source data at the end. Otherwise, you'll get raw deflate data.
// TDEFL_COMPUTE_ADLER32: Always compute the adler-32 of the input data (even when not writing zlib headers).
// TDEFL_GREEDY_PARSING_FLAG: Set to use faster greedy parsing, instead of more efficient lazy parsing.
// TDEFL_NONDETERMINISTIC_PARSING_FLAG: Enable to decrease the compressor's initialization time to the minimum, but the output may vary from run to run given the same input (depending on the contents of memory).
// TDEFL_RLE_MATCHES: Only look for RLE matches (matches with a distance of 1)
// TDEFL_FILTER_MATCHES: Discards matches <= 5 chars if enabled.
// TDEFL_FORCE_ALL_STATIC_BLOCKS: Disable usage of optimized Huffman tables.
// TDEFL_FORCE_ALL_RAW_BLOCKS: Only use raw (uncompressed) deflate blocks.
// The low 12 bits are reserved to control the max # of hash probes per dictionary lookup (see TDEFL_MAX_PROBES_MASK).
enum
{
    TDEFL_WRITE_ZLIB_HEADER = 0x01000,
    TDEFL_COMPUTE_ADLER32 = 0x02000,
    TDEFL_GREEDY_PARSING_FLAG = 0x04000,
    TDEFL_NONDETERMINISTIC_PARSING_FLAG = 0x08000,
    TDEFL_RLE_MATCHES = 0x10000,
    TDEFL_FILTER_MATCHES = 0x20000,
    TDEFL_FORCE_ALL_STATIC_BLOCKS = 0x40000,
    TDEFL_FORCE_ALL_RAW_BLOCKS = 0x80000
};

// High level compression functions:
// tdefl_compress_mem_to_heap() compresses a block in memory to a heap block allocated via malloc().
// On entry:
//  pSrc_buf, src_buf_len: Pointer and size of source block to compress.
//  flags: The max match finder probes (default is 128) logically OR'd against the above flags. Higher probes are slower but improve compression.
// On return:
//  Function returns a pointer to the compressed data, or NULL on failure.
//  *pOut_len will be set to the compressed data's size, which could be larger than src_buf_len on uncompressible data.
//  The caller must free() the returned block when it's no longer needed.
void *tdefl_compress_mem_to_heap(const void *pSrc_buf, size_t src_buf_len, size_t *pOut_len, int flags);

// tdefl_compress_mem_to_mem() compresses a block in memory to another block in memory.
// Returns 0 on failure.
size_t tdefl_compress_mem_to_mem(void *pOut_buf, size_t out_buf_len, const void *pSrc_buf, size_t src_buf_len, int flags);

// Compresses an image to a compressed PNG file in memory.
// On entry:
//  pImage, w, h, and num_chans describe the image to compress. num_chans may be 1, 2, 3, or 4.
//  The image pitch in bytes per scanline will be w*num_chans. The leftmost pixel on the top scanline is stored first in memory.
//  level may range from [0,10], use MZ_NO_COMPRESSION, MZ_BEST_SPEED, MZ_BEST_COMPRESSION, etc. or a decent default is MZ_DEFAULT_LEVEL
//  If flip is true, the image will be flipped on the Y axis (useful for OpenGL apps).
// On return:
//  Function returns a pointer to the compressed data, or NULL on failure.
//  *pLen_out will be set to the size of the PNG image file.
//  The caller must mz_free() the returned heap block (which will typically be larger than *pLen_out) when it's no longer needed.
void *tdefl_write_image_to_png_file_in_memory_ex(const void *pImage, int w, int h, int num_chans, size_t *pLen_out, mz_uint level, mz_bool flip);
void *tdefl_write_image_to_png_file_in_memory(const void *pImage, int w, int h, int num_chans, size_t *pLen_out);

// Output stream interface. The compressor uses this interface to write compressed data. It'll typically be called TDEFL_OUT_BUF_SIZE at a time.
typedef mz_bool (*tdefl_put_buf_func_ptr)(const void *pBuf, int len, void *pUser);

// tdefl_compress_mem_to_output() compresses a block to an output stream. The above helpers use this function internally.
mz_bool tdefl_compress_mem_to_output(const void *pBuf, size_t buf_len, tdefl_put_buf_func_ptr pPut_buf_func, void *pPut_buf_user, int flags);

enum
{
    TDEFL_MAX_HUFF_TABLES = 3,
    TDEFL_MAX_HUFF_SYMBOLS_0 = 288,
    TDEFL_MAX_HUFF_SYMBOLS_1 = 32,
    TDEFL_MAX_HUFF_SYMBOLS_2 = 19,
    TDEFL_LZ_DICT_SIZE = 32768,
    TDEFL_LZ_DICT_SIZE_MASK = TDEFL_LZ_DICT_SIZE - 1,
    TDEFL_MIN_MATCH_LEN = 3,
    TDEFL_MAX_MATCH_LEN = 258
};

// TDEFL_OUT_BUF_SIZE MUST be large enough to hold a single entire compressed output block (using static/fixed Huffman codes).
#if TDEFL_LESS_MEMORY
enum
{
    TDEFL_LZ_CODE_BUF_SIZE = 24 * 1024,
    TDEFL_OUT_BUF_SIZE = (TDEFL_LZ_CODE_BUF_SIZE * 13) / 10,
    TDEFL_MAX_HUFF_SYMBOLS = 288,
    TDEFL_LZ_HASH_BITS = 12,
    TDEFL_LEVEL1_HASH_SIZE_MASK = 4095,
    TDEFL_LZ_HASH_SHIFT = (TDEFL_LZ_HASH_BITS + 2) / 3,
    TDEFL_LZ_HASH_SIZE = 1 << TDEFL_LZ_HASH_BITS
};
#else
enum
{
    TDEFL_LZ_CODE_BUF_SIZE = 64 * 1024,
    TDEFL_OUT_BUF_SIZE = (TDEFL_LZ_CODE_BUF_SIZE * 13) / 10,
    TDEFL_MAX_HUFF_SYMBOLS = 288,
    TDEFL_LZ_HASH_BITS = 15,
    TDEFL_LEVEL1_HASH_SIZE_MASK = 4095,
    TDEFL_LZ_HASH_SHIFT = (TDEFL_LZ_HASH_BITS + 2) / 3,
    TDEFL_LZ_HASH_SIZE = 1 << TDEFL_LZ_HASH_BITS
};
#endif

// The low-level tdefl functions below may be used directly if the above helper functions aren't flexible enough. The low-level functions don't make any heap allocations, unlike the above helper functions.
typedef enum {
    TDEFL_STATUS_BAD_PARAM = -2,
    TDEFL_STATUS_PUT_BUF_FAILED = -1,
    TDEFL_STATUS_OKAY = 0,
    TDEFL_STATUS_DONE = 1,
} tdefl_status;

// Must map to MZ_NO_FLUSH, MZ_SYNC_FLUSH, etc. enums
typedef enum {
    TDEFL_NO_FLUSH = 0,
    TDEFL_SYNC_FLUSH = 2,
    TDEFL_FULL_FLUSH = 3,
    TDEFL_FINISH = 4
} tdefl_flush;

// tdefl's compression state structure.
typedef struct
{
    tdefl_put_buf_func_ptr m_pPut_buf_func;
    void *m_pPut_buf_user;
    mz_uint m_flags, m_max_probes[2];
    int m_greedy_parsing;
    mz_uint m_adler32, m_lookahead_pos, m_lookahead_size, m_dict_size;
    mz_uint8 *m_pLZ_code_buf, *m_pLZ_flags, *m_pOutput_buf, *m_pOutput_buf_end;
    mz_uint m_num_flags_left, m_total_lz_bytes, m_lz_code_buf_dict_pos, m_bits_in, m_bit_buffer;
    mz_uint m_saved_match_dist, m_saved_match_len, m_saved_lit, m_output_flush_ofs, m_output_flush_remaining, m_finished, m_block_index, m_wants_to_finish;
    tdefl_status m_prev_return_status;
    const void *m_pIn_buf;
    void *m_pOut_buf;
    size_t *m_pIn_buf_size, *m_pOut_buf_size;
    tdefl_flush m_flush;
    const mz_uint8 *m_pSrc;
    size_t m_src_buf_left, m_out_buf_ofs;
    mz_uint8 m_dict[TDEFL_LZ_DICT_SIZE + TDEFL_MAX_MATCH_LEN - 1];
    mz_uint16 m_huff_count[TDEFL_MAX_HUFF_TABLES][TDEFL_MAX_HUFF_SYMBOLS];
    mz_uint16 m_huff_codes[TDEFL_MAX_HUFF_TABLES][TDEFL_MAX_HUFF_SYMBOLS];
    mz_uint8 m_huff_code_sizes[TDEFL_MAX_HUFF_TABLES][TDEFL_MAX_HUFF_SYMBOLS];
    mz_uint8 m_lz_code_buf[TDEFL_LZ_CODE_BUF_SIZE];
    mz_uint16 m_next[TDEFL_LZ_DICT_SIZE];
    mz_uint16 m_hash[TDEFL_LZ_HASH_SIZE];
    mz_uint8 m_output_buf[TDEFL_OUT_BUF_SIZE];
} tdefl_compressor;

// Initializes the compressor.
// There is no corresponding deinit() function because the tdefl API's do not dynamically allocate memory.
// pBut_buf_func: If NULL, output data will be supplied to the specified callback. In this case, the user should call the tdefl_compress_buffer() API for compression.
// If pBut_buf_func is NULL the user should always call the tdefl_compress() API.
// flags: See the above enums (TDEFL_HUFFMAN_ONLY, TDEFL_WRITE_ZLIB_HEADER, etc.)
tdefl_status tdefl_init(tdefl_compressor *d, tdefl_put_buf_func_ptr pPut_buf_func, void *pPut_buf_user, int flags);

// Compresses a block of data, consuming as much of the specified input buffer as possible, and writing as much compressed data to the specified output buffer as possible.
tdefl_status tdefl_compress(tdefl_compressor *d, const void *pIn_buf, size_t *pIn_buf_size, void *pOut_buf, size_t *pOut_buf_size, tdefl_flush flush);

// tdefl_compress_buffer() is only usable when the tdefl_init() is called with a non-NULL tdefl_put_buf_func_ptr.
// tdefl_compress_buffer() always consumes the entire input buffer.
tdefl_status tdefl_compress_buffer(tdefl_compressor *d, const void *pIn_buf, size_t in_buf_size, tdefl_flush flush);

tdefl_status tdefl_get_prev_return_status(tdefl_compressor *d);
mz_uint32 tdefl_get_adler32(tdefl_compressor *d);

// Can't use tdefl_create_comp_flags_from_zip_params if MINIZ_NO_ZLIB_APIS isn't defined, because it uses some of its macros.
#ifndef MINIZ_NO_ZLIB_APIS
// Create tdefl_compress() flags given zlib-style compression parameters.
// level may range from [0,10] (where 10 is absolute max compression, but may be much slower on some files)
// window_bits may be -15 (raw deflate) or 15 (zlib)
// strategy may be either MZ_DEFAULT_STRATEGY, MZ_FILTERED, MZ_HUFFMAN_ONLY, MZ_RLE, or MZ_FIXED
mz_uint tdefl_create_comp_flags_from_zip_params(int level, int window_bits, int strategy);
#endif // #ifndef MINIZ_NO_ZLIB_APIS

// Allocate the tdefl_compressor structure in C so that
// non-C language bindings to tdefl_ API don't need to worry about
// structure size and allocation mechanism.
tdefl_compressor *tdefl_compressor_alloc();
void tdefl_compressor_free(tdefl_compressor *pComp);