dmtxplacemod.c

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#include <assert.h>
 
#include "dmtx.h"
#include "dmtxstatic.h"
 
int dmtxSymbolModuleStatus(DmtxMessage *message, int sizeIdx, int symbolRow, int symbolCol)
{
    int symbolRowReverse;
    int mappingRow, mappingCol;
    int dataRegionRows, dataRegionCols;
    int symbolRows, mappingCols;
 
    dataRegionRows = dmtxGetSymbolAttribute(DmtxSymAttribDataRegionRows, sizeIdx);
    dataRegionCols = dmtxGetSymbolAttribute(DmtxSymAttribDataRegionCols, sizeIdx);
    symbolRows = dmtxGetSymbolAttribute(DmtxSymAttribSymbolRows, sizeIdx);
    mappingCols = dmtxGetSymbolAttribute(DmtxSymAttribMappingMatrixCols, sizeIdx);
 
    symbolRowReverse = symbolRows - symbolRow - 1;
    mappingRow = symbolRowReverse - 1 - 2 * (symbolRowReverse / (dataRegionRows + 2));
    mappingCol = symbolCol - 1 - 2 * (symbolCol / (dataRegionCols + 2));
 
    /* Solid portion of alignment patterns */
    if (symbolRow % (dataRegionRows + 2) == 0 || symbolCol % (dataRegionCols + 2) == 0) {
        return (DmtxModuleOnRGB | (!DmtxModuleData));
    }
 
    /* Horinzontal calibration bars */
    if ((symbolRow + 1) % (dataRegionRows + 2) == 0) {
        return (((symbolCol & 0x01) ? 0 : DmtxModuleOnRGB) | (!DmtxModuleData));
    }
 
    /* Vertical calibration bars */
    if ((symbolCol + 1) % (dataRegionCols + 2) == 0) {
        return (((symbolRow & 0x01) ? 0 : DmtxModuleOnRGB) | (!DmtxModuleData));
    }
 
    /* Data modules */
    return (message->array[mappingRow * mappingCols + mappingCol] | DmtxModuleData);
}
 
static int modulePlacementEcc200(INOUT unsigned char *modules, OUT unsigned char *codewords, int sizeIdx,
                                 int moduleOnColor)
{
    int row, col, chr;
    int mappingRows, mappingCols;
 
    DmtxAssert(moduleOnColor & (DmtxModuleOnRed | DmtxModuleOnGreen | DmtxModuleOnBlue));
 
    mappingRows = dmtxGetSymbolAttribute(DmtxSymAttribMappingMatrixRows, sizeIdx);
    mappingCols = dmtxGetSymbolAttribute(DmtxSymAttribMappingMatrixCols, sizeIdx);
 
    /* 初始化：寻找第一个字符的第8位的起始位置 */
    chr = 0;
    row = 4;
    col = 0;
 
    do {
        /* 检查并处理四个特殊角落的码字排布模式 */
        if ((row == mappingRows) && (col == 0)) {
            patternShapeSpecial1(modules, mappingRows, mappingCols, &(codewords[chr++]), moduleOnColor);
        } else if ((row == mappingRows - 2) && (col == 0) && (mappingCols % 4 != 0)) {
            patternShapeSpecial2(modules, mappingRows, mappingCols, &(codewords[chr++]), moduleOnColor);
        } else if ((row == mappingRows - 2) && (col == 0) && (mappingCols % 8 == 4)) {
            patternShapeSpecial3(modules, mappingRows, mappingCols, &(codewords[chr++]), moduleOnColor);
        } else if ((row == mappingRows + 4) && (col == 2) && (mappingCols % 8 == 0)) {
            patternShapeSpecial4(modules, mappingRows, mappingCols, &(codewords[chr++]), moduleOnColor);
        }
 
        /* 以对角线方式斜向上扫描并插入字符 */
        do {
            if ((row < mappingRows) && (col >= 0) && !(modules[row * mappingCols + col] & DmtxModuleVisited)) {
                patternShapeStandard(modules, mappingRows, mappingCols, row, col, &(codewords[chr++]), moduleOnColor);
            }
            row -= 2;
            col += 2;
        } while ((row >= 0) && (col < mappingCols));
        row += 1;
        col += 3;
 
        /* 同样以对角线方式向下扫描并插入字符 */
        do {
            if ((row >= 0) && (col < mappingCols) && !(modules[row * mappingCols + col] & DmtxModuleVisited)) {
                patternShapeStandard(modules, mappingRows, mappingCols, row, col, &(codewords[chr++]), moduleOnColor);
            }
            row += 2;
            col -= 2;
        } while ((row < mappingRows) && (col >= 0));
        row += 3;
        col += 1;
        /* 重复此过程，直到扫描完整个modules数组 */
    } while ((row < mappingRows) || (col < mappingCols));
 
    /* 处理右下角的固定模式 */
    if (!(modules[mappingRows * mappingCols - 1] & DmtxModuleVisited)) {
        modules[mappingRows * mappingCols - 1] |= moduleOnColor;
        modules[(mappingRows * mappingCols) - mappingCols - 2] |= moduleOnColor;
    } /* XXX should this fixed pattern also be used in reading somehow? */
 
    /* XXX compare that chr == region->dataSize here */
    return chr; /* XXX number of codewords read off */
}
 
static void patternShapeStandard(unsigned char *modules, int mappingRows, int mappingCols, int row, int col,
                                 unsigned char *codeword, int moduleOnColor)
{
    placeModule(modules, mappingRows, mappingCols, row - 2, col - 2, codeword, DmtxMaskBit1, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, row - 2, col - 1, codeword, DmtxMaskBit2, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, row - 1, col - 2, codeword, DmtxMaskBit3, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, row - 1, col - 1, codeword, DmtxMaskBit4, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, row - 1, col, codeword, DmtxMaskBit5, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, row, col - 2, codeword, DmtxMaskBit6, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, row, col - 1, codeword, DmtxMaskBit7, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, row, col, codeword, DmtxMaskBit8, moduleOnColor);
}
 
static void patternShapeSpecial1(unsigned char *modules, int mappingRows, int mappingCols, unsigned char *codeword,
                                 int moduleOnColor)
{
    placeModule(modules, mappingRows, mappingCols, mappingRows - 1, 0, codeword, DmtxMaskBit1, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, mappingRows - 1, 1, codeword, DmtxMaskBit2, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, mappingRows - 1, 2, codeword, DmtxMaskBit3, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 0, mappingCols - 2, codeword, DmtxMaskBit4, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 0, mappingCols - 1, codeword, DmtxMaskBit5, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 1, mappingCols - 1, codeword, DmtxMaskBit6, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 2, mappingCols - 1, codeword, DmtxMaskBit7, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 3, mappingCols - 1, codeword, DmtxMaskBit8, moduleOnColor);
}
 
static void patternShapeSpecial2(unsigned char *modules, int mappingRows, int mappingCols, unsigned char *codeword,
                                 int moduleOnColor)
{
    placeModule(modules, mappingRows, mappingCols, mappingRows - 3, 0, codeword, DmtxMaskBit1, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, mappingRows - 2, 0, codeword, DmtxMaskBit2, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, mappingRows - 1, 0, codeword, DmtxMaskBit3, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 0, mappingCols - 4, codeword, DmtxMaskBit4, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 0, mappingCols - 3, codeword, DmtxMaskBit5, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 0, mappingCols - 2, codeword, DmtxMaskBit6, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 0, mappingCols - 1, codeword, DmtxMaskBit7, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 1, mappingCols - 1, codeword, DmtxMaskBit8, moduleOnColor);
}
 
static void patternShapeSpecial3(unsigned char *modules, int mappingRows, int mappingCols, unsigned char *codeword,
                                 int moduleOnColor)
{
    placeModule(modules, mappingRows, mappingCols, mappingRows - 3, 0, codeword, DmtxMaskBit1, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, mappingRows - 2, 0, codeword, DmtxMaskBit2, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, mappingRows - 1, 0, codeword, DmtxMaskBit3, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 0, mappingCols - 2, codeword, DmtxMaskBit4, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 0, mappingCols - 1, codeword, DmtxMaskBit5, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 1, mappingCols - 1, codeword, DmtxMaskBit6, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 2, mappingCols - 1, codeword, DmtxMaskBit7, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 3, mappingCols - 1, codeword, DmtxMaskBit8, moduleOnColor);
}
 
static void patternShapeSpecial4(unsigned char *modules, int mappingRows, int mappingCols, unsigned char *codeword,
                                 int moduleOnColor)
{
    placeModule(modules, mappingRows, mappingCols, mappingRows - 1, 0, codeword, DmtxMaskBit1, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, mappingRows - 1, mappingCols - 1, codeword, DmtxMaskBit2,
                moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 0, mappingCols - 3, codeword, DmtxMaskBit3, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 0, mappingCols - 2, codeword, DmtxMaskBit4, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 0, mappingCols - 1, codeword, DmtxMaskBit5, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 1, mappingCols - 3, codeword, DmtxMaskBit6, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 1, mappingCols - 2, codeword, DmtxMaskBit7, moduleOnColor);
    placeModule(modules, mappingRows, mappingCols, 1, mappingCols - 1, codeword, DmtxMaskBit8, moduleOnColor);
}
 
static void placeModule(unsigned char *modules, int mappingRows, int mappingCols, int row, int col,
                        unsigned char *codeword, int mask, int moduleOnColor)
{
    if (row < 0) {
        row += mappingRows;
        col += 4 - ((mappingRows + 4) % 8);
    }
    if (col < 0) {
        col += mappingCols;
        row += 4 - ((mappingCols + 4) % 8);
    }
 
    if ((modules[row * mappingCols + col] & DmtxModuleAssigned) != 0) { /* 解码 */
        if ((modules[row * mappingCols + col] & moduleOnColor) != 0) {
            *codeword |= mask;
        } else {
            *codeword &= (0xff ^ mask);
        }
    } else { /* 编码 */
        if ((*codeword & mask) != 0x00) {
            modules[row * mappingCols + col] |= moduleOnColor;
        }
 
        modules[row * mappingCols + col] |= DmtxModuleAssigned;
    }
 
    modules[row * mappingCols + col] |= DmtxModuleVisited;
}