irrlicht/source/Irrlicht/CMY3DHelper.h

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// Copyright (C) 2002-2007 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h
//
// This file was originally written by ZDimitor.
//----------------------------------------------------------------------
// somefuncs.h - part of the My3D Tools
//
// This tool was created by Zhuck Dmitry (ZDimitor).
// Everyone can use it as wants ( i'll be happy if it helps to someone :) ).
//----------------------------------------------------------------------
//**********************************************************************
// some useful functions
//**********************************************************************
#ifndef __C_MY3D_HELPER_H_INCLUDED__
#define __C_MY3D_HELPER_H_INCLUDED__
//--------------------------------------------------------------------------------
namespace irr
{
namespace core
{
//-----------------RLE stuff-----------------------------------------
int rle_encode (
unsigned char *in_buf, int in_buf_size,
unsigned char *out_buf, int out_buf_size
);
unsigned long process_comp(
unsigned char *buf, int buf_size,
unsigned char *out_buf, int out_buf_size
);
void process_uncomp(
unsigned char, unsigned char *out_buf, int out_buf_size
);
void flush_outbuf(
unsigned char *out_buf, int out_buf_size
);
unsigned long get_byte (
unsigned char *ch,
unsigned char *in_buf, int in_buf_size,
unsigned char *out_buf, int out_buf_size
);
void put_byte(
unsigned char ch, unsigned char *out_buf, int out_buf_size
);
//-----------------------------------------------------------
const unsigned long LIMIT = 1; // was #define LIMIT 1
const unsigned long NON_MATCH = 2; // was: #define NON_MATCH 2
const unsigned long EOD_FOUND = 3; // was: #define EOD_FOUND 3
const unsigned long EOD = 0x00454f44; // was: #define EOD 'EOD'
//-----------------------------------------------------------
// number of decoded bytes
static int nDecodedBytes=0;
// number of coded bytes
static int nCodedBytes=0;
// number of read bytes
static int nReadedBytes=0;
// table used to look for sequences of repeating bytes
static unsigned char tmpbuf[4]; // we use subscripts 1 - 3
static int tmpbuf_cnt;
// output buffer for non-compressed output data
static unsigned char outbuf[128];
static int outbuf_cnt;
//-----------------------------------------------------------
int rle_encode (
unsigned char *in_buf, int in_buf_size,
unsigned char *out_buf, int out_buf_size
)
{
unsigned long ret_code;
unsigned char ch;
nCodedBytes=0;
nReadedBytes=0;
tmpbuf_cnt = 0; // no. of char's in tmpbuf
outbuf_cnt = 0; // no. of char's in outbuf
while (1)
{
if (get_byte(&ch, in_buf, in_buf_size,
out_buf, out_buf_size) == (int)EOD) // read next byte into ch
break;
tmpbuf[++tmpbuf_cnt] = (unsigned char) ch;
if (tmpbuf_cnt == 3)
{
// see if all 3 match each other
if ((tmpbuf[1] == tmpbuf[2]) && (tmpbuf[2] == tmpbuf[3]))
{
// they do - add compression
// this will process all bytes in input file until
// a non-match occurs, or 128 bytes are processed,
// or we find eod */
ret_code = process_comp(in_buf, in_buf_size, out_buf, out_buf_size);
if (ret_code == (int)EOD_FOUND)
break; // stop compressing
if (ret_code == (int)NON_MATCH)
tmpbuf_cnt=1; /* save the char that didn't match */
else
// we just compressed the max. of 128 bytes
tmpbuf_cnt=0; /* start over for next chunk */
}
else
{
// we know the first byte doesn't match 2 or more
// others, so just send it out as uncompressed. */
process_uncomp(tmpbuf[1], out_buf, out_buf_size);
// see if the last 2 bytes in the buffer match
if (tmpbuf[2] == tmpbuf[3])
{
// move byte 3 to position 1 and pretend we just
// have 2 bytes -- note that the first byte was
// already sent to output */
tmpbuf[1]=tmpbuf[3];
tmpbuf_cnt=2;
}
else
{
// send byte 2 and keep byte 3 - it may match the
// next byte. Move byte 3 to position 1 and set
// count to 1. Note that the first byte was
// already sent to output
process_uncomp(tmpbuf[2], out_buf, out_buf_size);
tmpbuf[1]=tmpbuf[3];
tmpbuf_cnt=1;
}
}
}
} // end while
flush_outbuf(out_buf, out_buf_size);
return nCodedBytes;
}
//------------------------------------------------------------------
// This flushes any non-compressed data not yet sent, then it processes
// repeating bytes until > 128, or EOD, or non-match.
// return values: LIMIT, EOD_FOUND, NON_MATCH
// Prior to ANY return, it writes out the 2 byte compressed code.
// If a NON_MATCH was found, this returns with the non-matching char
// residing in tmpbuf[0].
// Inputs: tmpbuf[0], input file
// Outputs: tmpbuf[0] (sometimes), output file, and return code
//------------------------------------------------------------------
unsigned long process_comp(
unsigned char *buf, int buf_size,
unsigned char *out_buf, int out_buf_size)
{
// we start out with 3 repeating bytes
register int len = 3;
unsigned char ch;
// we're starting a repeating chunk - end the non-repeaters
flush_outbuf(out_buf, out_buf_size);
while (get_byte(&ch, buf, buf_size, out_buf, out_buf_size) != (int)EOD)
{
if (ch != tmpbuf[1])
{
// send no. of repeated bytes to be encoded
put_byte((unsigned char)((--len) | 0x80), out_buf, out_buf_size);
// send the byte's value being repeated
put_byte((unsigned char)tmpbuf[1], out_buf, out_buf_size);
/* save the non-matching character just read */
tmpbuf[1]=(unsigned char) ch;
return NON_MATCH;
}
/* we know the new byte is part of the repeating seq */
len++;
if (len == 128)
{
// send no. of repeated bytes to be encoded
put_byte((unsigned char)((--len) | 0x80), out_buf, out_buf_size);
// send the byte's value being repeated
put_byte((unsigned char)tmpbuf[1], out_buf, out_buf_size);
return LIMIT;
}
} // end while
// if flow comes here, we just read an EOD
// send no. of repeated bytes to be encoded
put_byte((unsigned char)((--len) | 0x80), out_buf, out_buf_size);
// send the byte's value being repeated
put_byte((unsigned char)tmpbuf[1], out_buf, out_buf_size);
return EOD_FOUND;
}
//----------------------------------------------------------------
// This adds 1 non-repeating byte to outbuf. If outbuf becomes full
// with 128 bytes, it flushes outbuf.
// There are no return codes and no bytes are read from the input.
//----------------------------------------------------------------
void process_uncomp(
unsigned char char1, unsigned char *out_buf, int out_buf_size
)
{
outbuf[outbuf_cnt++] = char1;
if (outbuf_cnt == 128)
flush_outbuf(out_buf, out_buf_size);
}
//-----------------------------------------------------------
// This flushes any non-compressed data not yet sent.
// On exit, outbuf_cnt will equal zero.
//-----------------------------------------------------------
void flush_outbuf(unsigned char *out_buf, int out_buf_size)
{
register int pos=0;
if(!outbuf_cnt)
return; // nothing to do */
// send no. of unencoded bytes to be sent
put_byte((unsigned char)(outbuf_cnt - 1), out_buf, out_buf_size);
for ( ; outbuf_cnt; outbuf_cnt--)
put_byte((unsigned char)outbuf[pos++], out_buf, out_buf_size);
}
//---------------------------------------------------
void put_byte(unsigned char ch, unsigned char *out_buf, int out_buf_size)
{
if (nCodedBytes<=(out_buf_size-1))
{ out_buf[nCodedBytes++]=ch;
out_buf[nCodedBytes]=0;
}
}
//---------------------------------------------------
// This reads the next byte into ch. It returns EOD
// at end-of-data
//---------------------------------------------------
unsigned long get_byte(
unsigned char *ch,
unsigned char *in_buf, int in_buf_size,
unsigned char *out_buf, int out_buf_size
)
{
if (nReadedBytes>=in_buf_size)
{
// there are either 0, 1, or 2 char's to write before we quit
if (tmpbuf_cnt == 1)
process_uncomp(tmpbuf[1], out_buf, out_buf_size);
else
{
if (tmpbuf_cnt == 2)
{
process_uncomp(tmpbuf[1], out_buf, out_buf_size);
process_uncomp(tmpbuf[2], out_buf, out_buf_size);
}
}
nReadedBytes =0;
return EOD;
}
(*ch) = (unsigned char)in_buf[nReadedBytes++];
return 0;
}
//-----------------------------------------------------------
int rle_decode (
unsigned char *in_buf, int in_buf_size,
unsigned char *out_buf, int out_buf_size
)
{
nDecodedBytes=0;
nReadedBytes=0;
int ch, i;
while (1)
{
if (nReadedBytes>=in_buf_size)
break;
else
ch=in_buf[nReadedBytes];
nReadedBytes++;
if (ch > 127)
{
i = ch - 127; // i is the number of repetitions
// get the byte to be repeated
if (nReadedBytes>=in_buf_size)
break;
else
ch=in_buf[nReadedBytes];
nReadedBytes++;
// uncompress a chunk
for ( ; i ; i--)
{
if (nDecodedBytes<out_buf_size)
out_buf[nDecodedBytes] = ch;
nDecodedBytes++;
}
}
else
{
// copy out some uncompressed bytes
i = ch + 1; // i is the no. of bytes
// uncompress a chunk
for ( ; i ; i--)
{
if (nReadedBytes>=in_buf_size)
break;
else
ch=in_buf[nReadedBytes];
nReadedBytes++;
if (nDecodedBytes<out_buf_size)
out_buf[nDecodedBytes] = ch;
nDecodedBytes++;
}
}
} // end while
return nDecodedBytes;
}
} //end namespace core
} //end namespace irr
#endif // __C_MY3D_HELPER_H_INCLUDED__