summaryrefslogtreecommitdiff
path: root/Build/source/utils/asymptote/prc/PRCTools/bitData.cc
blob: 19274a8b4b75e10f18717f6fc02a3eb34c48d1f2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
/************
*
*   This file is part of a tool for reading 3D content in the PRC format.
*   Copyright (C) 2008 Orest Shardt <shardtor (at) gmail dot com>
*
*   This program is free software: you can redistribute it and/or modify
*   it under the terms of the GNU Lesser General Public License as published by
*   the Free Software Foundation, either version 3 of the License, or
*   (at your option) any later version.
*
*   This program is distributed in the hope that it will be useful,
*   but WITHOUT ANY WARRANTY; without even the implied warranty of
*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*   GNU Lesser General Public License for more details.
*
*   You should have received a copy of the GNU Lesser General Public License
*   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*
*************/

#include "../PRC.h"
#include "../PRCdouble.h"
#include "bitData.h"

using std::cout; using std::endl; using std::hex; using std::cerr;

BitPosition BitByBitData::getPosition()
{
  BitPosition bp;
  bp.byteIndex = data - start;
  bp.bitIndex = 0;
  for(unsigned char temp = bitMask<<1; temp != 0; temp <<= 1)
    bp.bitIndex++;
  return bp;
}

void BitByBitData::setPosition(const BitPosition& bp)
{
  if(bp.byteIndex < length)
  {
    data = start + bp.byteIndex;
    bitMask = 0x80 >> bp.bitIndex;
    // big-endian, zero based bit index (from 0 to 7)
    // so 0x80 => bit 0, 0x01 => bit 7
    // Why? It is easy to see in a hex editor.
    failed = false;
  }
  else
  {
    failed = true;
  }
}

void BitByBitData::setPosition(unsigned int byte, unsigned int bit)
{
  if(byte <= length)
  {
    data = start + byte;
    bitMask = 0x80 >> bit;
    // big-endian, zero based bit index (from 0 to 7)
    // so 0x80 => bit 0, 0x01 => bit 7
    // Why? It is easy to see in a hex editor.
    failed = false;
  }
  else
  {
    failed = true;
  }
}

void BitByBitData::setShowBits(bool val)
{
  showBits = val;
}

void BitByBitData::tellPosition()
{
  BitPosition bp = getPosition();
  cout << bp.byteIndex << ':' << bp.bitIndex << endl;
}

bool BitByBitData::readBit()
{
  if(!failed)
  {
    bool val = *data & bitMask;
    if(showBits) cout << (val?'1':'0');
    nextBit();
    return val;
  }
  else
    return false;
}

unsigned char BitByBitData::readChar()
{
  unsigned char dat = 0;
  dat |= readBit();
  for(int a = 0; a < 7; ++a)
  {
    dat <<= 1;
    dat |= readBit();
  }
  return dat;
}

unsigned int BitByBitData::readUnsignedInt()
{
  unsigned int result = 0;
  unsigned int count = 0;
  while(readBit())
  {
    result |= (static_cast<unsigned int>(readChar()) << 8*count++);
  }
  if(showBits) cout << " " << result << endl;
  return result;
}

std::string BitByBitData::readString()
{
  bool isNotNull = readBit();
  std::string result;
  if(isNotNull)
  {
    unsigned int stringLength = readUnsignedInt();
    char *buf = new char[stringLength+1];
    buf[stringLength] = '\0';
    for(unsigned int a = 0; a < stringLength; ++a)
    {
      buf[a] = readChar();
    }
    result = buf;
    delete[] buf;
  }
  if(showBits) cout << " " << result << endl;
  return result;
}

int BitByBitData::readInt()
{
  int result = 0;
  unsigned int count = 0;
  while(readBit())
  {
    result |= (static_cast<unsigned int>(readChar()) << 8*count++);
  }
  result <<= (4-count)*8;
  result >>= (4-count)*8;
  if(showBits) cout << " " << result << endl;
  return result;
}


// Thanks to Michail Vidiassov
double BitByBitData::readDouble()
{
  ieee754_double value;
  value.d = 0;
  sCodageOfFrequentDoubleOrExponent *pcofdoe;
  unsigned int ucofdoe = 0;
  for(int i = 1; i <= 22; ++i)
  {
    ucofdoe <<= 1;
    ucofdoe |= readBit();
    if((pcofdoe = getcofdoe(ucofdoe,i)) != NULL)
      break;
  }
  value.d = pcofdoe->u2uod.Value;

  // check if zero
  if(pcofdoe->NumberOfBits==2 && pcofdoe->Bits==1 && pcofdoe->Type==VT_double)
    return value.d;

  value.ieee.negative = readBit(); // get sign

  if(pcofdoe->Type == VT_double) // double from list
    return value.d;

  if(readBit()==0) // no mantissa
    return value.d;

  // read the mantissa
  // read uppermost 4 bits of mantissa
  unsigned char b4 = 0;
  for(int i = 0; i < 4; ++i)
  {
    b4 <<= 1;
    b4 |= readBit();
  }

#if defined(WORDS_LITTLE_ENDIAN)
  *(reinterpret_cast<unsigned char*>(&value)+6) |= b4;
  unsigned char *lastByte = reinterpret_cast<unsigned char*>(&value)+0;
  unsigned char *currentByte = reinterpret_cast<unsigned char*>(&value)+5;
#elif defined(WORDS_BIG_ENDIAN)
  *(reinterpret_cast<unsigned char*>(&value)+1) |= b4;
  unsigned char *lastByte = reinterpret_cast<unsigned char*>(&value)+7;
  unsigned char *currentByte = reinterpret_cast<unsigned char*>(&value)+2;
#endif

  for(;MOREBYTE(currentByte,lastByte); NEXTBYTE(currentByte))
  {
    if(readBit())
    {
      // new byte
      *currentByte = readChar();
    }
    else
    {
      // get 3 bit offset
      unsigned int offset = 0;
      offset |= (readBit() << 2);
      offset |= (readBit() << 1);
      offset |= readBit();
      if(offset == 0)
      {
        // fill remaining bytes in mantissa with previous byte
        unsigned char pByte = BYTEAT(currentByte,1);
        for(;MOREBYTE(currentByte,lastByte); NEXTBYTE(currentByte))
          *currentByte = pByte;
        break;
      }
      else if(offset == 6)
      {
        // fill remaining bytes except last byte with previous byte
        unsigned char pByte = BYTEAT(currentByte,1);
        PREVIOUSBYTE(lastByte);
        for(;MOREBYTE(currentByte,lastByte); NEXTBYTE(currentByte))
          *currentByte = pByte;
        *currentByte = readChar();
        break;
      }
      else
      {
        // one repeated byte
        *currentByte = BYTEAT(currentByte,offset);
      }
    }
  }
  if(showBits) cout << " " << value.d << endl;
  return value.d;
}

void BitByBitData::nextBit()
{
  bitMask >>= 1;
  if(bitMask == 0)
  {
    if(data < start+length)
      data++;
    else
    {
      failed = true;
      cout << "End of data."<< endl;
    }
    bitMask = 0x80;
  }
}