io.h

/*******************************************************************************
 *  Project: libopencad
 *  Purpose: OpenSource CAD formats support library
 *  Author: Alexandr Borzykh, mush3d at gmail.com
 *  Author: Dmitry Baryshnikov, bishop.dev@gmail.com
 *  Language: C++
 *******************************************************************************
 *  The MIT License (MIT)
 *
 *  Copyright (c) 2016 Alexandr Borzykh
 *  Copyright (c) 2016 NextGIS, <info@nextgis.com>
 *
 *  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.
 *******************************************************************************/


#ifndef DWG_IO_H
#define DWG_IO_H

#include "cadheader.h"

#include <string>
#include <algorithm>

/* DATA TYPES CONSTANTS */

#define BITSHORT_NORMAL         0x0
#define BITSHORT_UNSIGNED_CHAR  0x1
#define BITSHORT_ZERO_VALUE     0x2
#define BITSHORT_256            0x3

#define BITLONG_NORMAL          0x0
#define BITLONG_UNSIGNED_CHAR   0x1
#define BITLONG_ZERO_VALUE      0x2
#define BITLONG_NOT_USED        0x3

#define BITDOUBLE_NORMAL        0x0
#define BITDOUBLE_ONE_VALUE     0x1
#define BITDOUBLE_ZERO_VALUE    0x2
#define BITDOUBLE_NOT_USED      0x3

#define BITDOUBLEWD_DEFAULT_VALUE  0x0
#define BITDOUBLEWD_4BYTES_PATCHED 0x1
#define BITDOUBLEWD_6BYTES_PATCHED 0x2
#define BITDOUBLEWD_FULL_RD        0x3


static const size_t DWGSentinelLength = 16;

static constexpr const char * DWGHeaderVariablesStart
            = "\xCF\x7B\x1F\x23\xFD\xDE\x38\xA9\x5F\x7C\x68\xB8\x4E\x6D\x33\x5F";
static constexpr const char * DWGHeaderVariablesEnd
            = "\x30\x84\xE0\xDC\x02\x21\xC7\x56\xA0\x83\x97\x47\xB1\x92\xCC\xA0";

static constexpr const char * DWGDSPreviewStart
            = "\x1F\x25\x6D\x07\xD4\x36\x28\x28\x9D\x57\xCA\x3F\x9D\x44\x10\x2B";
static constexpr const char * DWGDSPreviewEnd
            = "\xE0\xDA\x92\xF8\x2B\xc9\xD7\xD7\x62\xA8\x35\xC0\x62\xBB\xEF\xD4";

static constexpr const char * DWGDSClassesStart
            = "\x8D\xA1\xC4\xB8\xC4\xA9\xF8\xC5\xC0\xDC\xF4\x5F\xE7\xCF\xB6\x8A";
static constexpr const char * DWGDSClassesEnd
            = "\x72\x5E\x3B\x47\x3B\x56\x07\x3A\x3F\x23\x0B\xA0\x18\x30\x49\x75";

static constexpr const char * DWGSecondFileHeaderStart
            = "\xD4\x7B\x21\xCE\x28\x93\x9F\xBF\x53\x24\x40\x09\x12\x3C\xAA\x01";
static constexpr const char * DWGSecondFileHeaderEnd
            = "\x2B\x84\xDE\x31\xD7\x6C\x60\x40\xAC\xDB\xBF\xF6\xED\xC3\x55\xFE";



// TODO: probably it would be better to have no dependencies on <algorithm>.
template<typename T, typename S>
inline void SwapEndianness ( T &&object, S &&size )
{
    std::reverse (( char * ) & object, ( char * ) & object + size);
}

static const int DWGCRC8Table[256] =
{
    0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0,
    0x0280, 0xC241, 0xC601, 0x06C0, 0x0780, 0xC741,
    0x0500, 0xC5C1, 0xC481, 0x0440, 0xCC01, 0x0CC0,
    0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
    0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0,
    0x0880, 0xC841, 0xD801, 0x18C0, 0x1980, 0xD941,
    0x1B00, 0xDBC1, 0xDA81, 0x1A40, 0x1E00, 0xDEC1,
    0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
    0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0,
    0x1680, 0xD641, 0xD201, 0x12C0, 0x1380, 0xD341,
    0x1100, 0xD1C1, 0xD081, 0x1040, 0xF001, 0x30C0,
    0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
    0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0,
    0x3480, 0xF441, 0x3C00, 0xFCC1, 0xFD81, 0x3D40,
    0xFF01, 0x3FC0, 0x3E80, 0xFE41, 0xFA01, 0x3AC0,
    0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
    0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0,
    0x2A80, 0xEA41, 0xEE01, 0x2EC0, 0x2F80, 0xEF41,
    0x2D00, 0xEDC1, 0xEC81, 0x2C40, 0xE401, 0x24C0,
    0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
    0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0,
    0x2080, 0xE041, 0xA001, 0x60C0, 0x6180, 0xA141,
    0x6300, 0xA3C1, 0xA281, 0x6240, 0x6600, 0xA6C1,
    0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
    0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0,
    0x6E80, 0xAE41, 0xAA01, 0x6AC0, 0x6B80, 0xAB41,
    0x6900, 0xA9C1, 0xA881, 0x6840, 0x7800, 0xB8C1,
    0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
    0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1,
    0xBC81, 0x7C40, 0xB401, 0x74C0, 0x7580, 0xB541,
    0x7700, 0xB7C1, 0xB681, 0x7640, 0x7200, 0xB2C1,
    0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
    0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0,
    0x5280, 0x9241, 0x9601, 0x56C0, 0x5780, 0x9741,
    0x5500, 0x95C1, 0x9481, 0x5440, 0x9C01, 0x5CC0,
    0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
    0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0,
    0x5880, 0x9841, 0x8801, 0x48C0, 0x4980, 0x8941,
    0x4B00, 0x8BC1, 0x8A81, 0x4A40, 0x4E00, 0x8EC1,
    0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
    0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0,
    0x4680, 0x8641, 0x8201, 0x42C0, 0x4380, 0x8341,
    0x4100, 0x81C1, 0x8081, 0x4040
};

unsigned short CalculateCRC8( unsigned short initialVal, const char * ptr, int num );

long ReadRAWLONGLONG ( const char * pabyInput, size_t& nBitOffsetFromStart );
int ReadRAWLONG ( const char * pabyInput, size_t& nBitOffsetFromStart );
short ReadRAWSHORT ( const char * pabyInput, size_t& nBitOffsetFromStart );
double ReadRAWDOUBLE ( const char * pabyInput, size_t& nBitOffsetFromStart );
unsigned char Read2B ( const char * pabyInput, size_t& nBitOffsetFromStart );
unsigned char Read3B ( const char * pabyInput, size_t& nBitOffsetFromStart );
unsigned char Read4B ( const char * pabyInput, size_t& nBitOffsetFromStart );
CADHandle ReadHANDLE ( const char * pabyInput, size_t& nBitOffsetFromStart );
CADHandle ReadHANDLE8BLENGTH ( const char * pabyInput,
                               size_t & nBitOffsetFromStart );
void skipHANDLE(const char * pabyInput, size_t& nBitOffsetFromStart);
bool        ReadBIT ( const char * pabyInput, size_t& nBitOffsetFromStart );
void skipBIT(const char * pabyInput, size_t& nBitOffsetFromStart);
unsigned char ReadCHAR ( const char * pabyInput, size_t& nBitOffsetFromStart );
short ReadBITSHORT ( const char * pabyInput, size_t& nBitOffsetFromStart );
int ReadBITLONG ( const char * pabyInput, size_t& nBitOffsetFromStart );
double ReadBITDOUBLE ( const char * pabyInput, size_t& nBitOffsetFromStart );
void skipBITDOUBLE( const char * pabyInput, size_t& nBitOffsetFromStart );
double ReadBITDOUBLEWD ( const char * pabyInput, size_t& nBitOffsetFromStart,
                         double defaultvalue );
long ReadMCHAR ( const char * pabyInput, size_t& nBitOffsetFromStart );
long ReadUMCHAR ( const char * pabyInput, size_t& nBitOffsetFromStart );
unsigned int ReadMSHORT ( const char * pabyInput, size_t& nBitOffsetFromStart );
std::string ReadTV ( const char * pabyInput, size_t& nBitOffsetFromStart );
void skipTV(const char * pabyInput, size_t& nBitOffsetFromStart);
void skipBITLONG(const char * pabyInput, size_t& nBitOffsetFromStart);
void skipBITSHORT(const char * pabyInput, size_t& nBitOffsetFromStart);

#endif // DWG_IO_H