/*libdmtx - Data Matrix Encoding/Decoding LibraryCopyright (C) 2006 Mike LaughtonThis library is free software; you can redistribute it and/ormodify it under the terms of the GNU Lesser General PublicLicense as published by the Free Software Foundation; eitherversion 2.1 of the License, or (at your option) any later version.This library is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNULesser General Public License for more details.You should have received a copy of the GNU Lesser General PublicLicense along with this library; if not, write to the Free SoftwareFoundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USAContact: mike@dragonflylogic.com*//* $Id: dmtxplacemod.c,v 1.2 2006/09/18 17:55:46 mblaughton Exp $ *//** * XXX * * @param * @return XXX */static intModulePlacementEcc200(DmtxMatrixRegion *matrixRegion){   unsigned char *codewords;   int row, col, chr;   codewords = matrixRegion->code;   // Start in the nominal location for the 8th bit of the first character   chr = 0;   row = 4;   col = 0;   do {      // Repeatedly first check for one of the special corner cases, then ...      if((row == matrixRegion->dataRows) && (col == 0))         PatternShapeSpecial1(matrixRegion, &(codewords[chr++]));      else if((row == matrixRegion->dataRows-2) && (col == 0) && (matrixRegion->dataCols%4))         PatternShapeSpecial2(matrixRegion, &(codewords[chr++]));      else if((row == matrixRegion->dataRows-2) && (col == 0) && (matrixRegion->dataCols%8 == 4))         PatternShapeSpecial3(matrixRegion, &(codewords[chr++]));      else if((row == matrixRegion->dataRows+4) && (col == 2) && (!(matrixRegion->dataCols%8)))         PatternShapeSpecial4(matrixRegion, &(codewords[chr++]));      // Sweep upward diagonally, inserting successive characters, ...      do {         if((row < matrixRegion->dataRows) && (col >= 0) &&               !(matrixRegion->array[row*matrixRegion->dataCols+col] & DMTX_MODULE_VISITED))            PatternShapeStandard(matrixRegion, row, col, &(codewords[chr++]));         row -= 2;         col += 2;      } while ((row >= 0) && (col < matrixRegion->dataCols));      row += 1;      col += 3;      // And then sweep downward diagonally, inserting successive characters, ...      do {         if((row >= 0) && (col < matrixRegion->dataCols) &&               !(matrixRegion->array[row*matrixRegion->dataCols+col] & DMTX_MODULE_VISITED))            PatternShapeStandard(matrixRegion, row, col, &(codewords[chr++]));         row += 2;         col -= 2;      } while ((row < matrixRegion->dataRows) && (col >= 0));      row += 3;      col += 1;      // ... until the entire array is scanned   } while ((row < matrixRegion->dataRows) || (col < matrixRegion->dataCols));   // XXX compare that chr == matrixRegion->dataSize here   return chr; // XXX number of codewords read off}/** * XXX * * @param * @return XXX */static voidPatternShapeStandard(DmtxMatrixRegion *matrixRegion, int row, int col, unsigned char *codeword){   PlaceModule(matrixRegion, row-2, col-2, codeword, DmtxMaskBit1);   PlaceModule(matrixRegion, row-2, col-1, codeword, DmtxMaskBit2);   PlaceModule(matrixRegion, row-1, col-2, codeword, DmtxMaskBit3);   PlaceModule(matrixRegion, row-1, col-1, codeword, DmtxMaskBit4);   PlaceModule(matrixRegion, row-1, col,   codeword, DmtxMaskBit5);   PlaceModule(matrixRegion, row,   col-2, codeword, DmtxMaskBit6);   PlaceModule(matrixRegion, row,   col-1, codeword, DmtxMaskBit7);   PlaceModule(matrixRegion, row,   col,   codeword, DmtxMaskBit8);}/** * XXX * * @param * @return XXX */static voidPatternShapeSpecial1(DmtxMatrixRegion *matrixRegion, unsigned char *codeword){   PlaceModule(matrixRegion, matrixRegion->dataRows-1, 0, codeword, DmtxMaskBit1);   PlaceModule(matrixRegion, matrixRegion->dataRows-1, 1, codeword, DmtxMaskBit2);   PlaceModule(matrixRegion, matrixRegion->dataRows-1, 2, codeword, DmtxMaskBit3);   PlaceModule(matrixRegion, 0, matrixRegion->dataCols-2, codeword, DmtxMaskBit4);   PlaceModule(matrixRegion, 0, matrixRegion->dataCols-1, codeword, DmtxMaskBit5);   PlaceModule(matrixRegion, 1, matrixRegion->dataCols-1, codeword, DmtxMaskBit6);   PlaceModule(matrixRegion, 2, matrixRegion->dataCols-1, codeword, DmtxMaskBit7);   PlaceModule(matrixRegion, 3, matrixRegion->dataCols-1, codeword, DmtxMaskBit8);}/** * XXX * * @param * @return XXX */static voidPatternShapeSpecial2(DmtxMatrixRegion *matrixRegion, unsigned char *codeword){   PlaceModule(matrixRegion, matrixRegion->dataRows-3, 0, codeword, DmtxMaskBit1);   PlaceModule(matrixRegion, matrixRegion->dataRows-2, 0, codeword, DmtxMaskBit2);   PlaceModule(matrixRegion, matrixRegion->dataRows-1, 0, codeword, DmtxMaskBit3);   PlaceModule(matrixRegion, 0, matrixRegion->dataCols-4, codeword, DmtxMaskBit4);   PlaceModule(matrixRegion, 0, matrixRegion->dataCols-3, codeword, DmtxMaskBit5);   PlaceModule(matrixRegion, 0, matrixRegion->dataCols-2, codeword, DmtxMaskBit6);   PlaceModule(matrixRegion, 0, matrixRegion->dataCols-1, codeword, DmtxMaskBit7);   PlaceModule(matrixRegion, 1, matrixRegion->dataCols-1, codeword, DmtxMaskBit8);}/** * XXX * * @param * @return XXX */static voidPatternShapeSpecial3(DmtxMatrixRegion *matrixRegion, unsigned char *codeword){   PlaceModule(matrixRegion, matrixRegion->dataRows-3, 0, codeword, DmtxMaskBit1);   PlaceModule(matrixRegion, matrixRegion->dataRows-2, 0, codeword, DmtxMaskBit2);   PlaceModule(matrixRegion, matrixRegion->dataRows-1, 0, codeword, DmtxMaskBit3);   PlaceModule(matrixRegion, 0, matrixRegion->dataCols-2, codeword, DmtxMaskBit4);   PlaceModule(matrixRegion, 0, matrixRegion->dataCols-1, codeword, DmtxMaskBit5);   PlaceModule(matrixRegion, 1, matrixRegion->dataCols-1, codeword, DmtxMaskBit6);   PlaceModule(matrixRegion, 2, matrixRegion->dataCols-1, codeword, DmtxMaskBit7);   PlaceModule(matrixRegion, 3, matrixRegion->dataCols-1, codeword, DmtxMaskBit8);}/** * XXX * * @param * @return XXX */static voidPatternShapeSpecial4(DmtxMatrixRegion *matrixRegion, unsigned char *codeword){   PlaceModule(matrixRegion, matrixRegion->dataRows-1, 0, codeword, DmtxMaskBit1);   PlaceModule(matrixRegion, matrixRegion->dataRows-1, matrixRegion->dataCols-1, codeword, DmtxMaskBit2);   PlaceModule(matrixRegion, 0, matrixRegion->dataCols-3, codeword, DmtxMaskBit3);   PlaceModule(matrixRegion, 0, matrixRegion->dataCols-2, codeword, DmtxMaskBit4);   PlaceModule(matrixRegion, 0, matrixRegion->dataCols-1, codeword, DmtxMaskBit5);   PlaceModule(matrixRegion, 1, matrixRegion->dataCols-3, codeword, DmtxMaskBit6);   PlaceModule(matrixRegion, 1, matrixRegion->dataCols-2, codeword, DmtxMaskBit7);   PlaceModule(matrixRegion, 1, matrixRegion->dataCols-1, codeword, DmtxMaskBit8);}/** * XXX * * @param * @return XXX */static voidPlaceModule(DmtxMatrixRegion *matrixRegion, int row, int col, unsigned char *codeword, DmtxBitMask mask){   if(row < 0) {      row += matrixRegion->dataRows;      col += 4 - ((matrixRegion->dataRows+4)%8);   }   if(col < 0) {      col += matrixRegion->dataCols;      row += 4 - ((matrixRegion->dataCols+4)%8);   }   // If module has already been assigned then we are decoding the pattern into codewords   if(matrixRegion->array[row*matrixRegion->dataCols+col] & DMTX_MODULE_ASSIGNED) {      if(!(matrixRegion->array[row*matrixRegion->dataCols+col] & DMTX_MODULE_ON))         *codeword |= mask;      else         *codeword &= (0xff ^ mask);   }   // Otherwise we are encoding the codewords into a pattern   else {      if(*codeword & mask)         matrixRegion->array[row*matrixRegion->dataCols+col] |= DMTX_MODULE_ON;      matrixRegion->array[row*matrixRegion->dataCols+col] |= DMTX_MODULE_ASSIGNED;   }   matrixRegion->array[row*matrixRegion->dataCols+col] |= DMTX_MODULE_VISITED;}