[Artoolkit] Marker of nftSimple

重点看：markers.dat 的解析原理

1.

int main(int argc, char** argv)
{
    char glutGamemode[];
    const char *cparam_name = "Data2/camera_para.dat";
    char vconf[] = "";
    const char markerConfigDataFilename[] = "Data2/markers.dat";

2.

    // Load marker(s).
    newMarkers(markerConfigDataFilename, &markersNFT, &markersNFTCount);
    if (!markersNFTCount) {
        ARLOGe("Error loading markers from config. file '%s'.\n", markerConfigDataFilename);
        cleanup();
        exit(-);
    }
    ARLOGi("Marker count = %d\n", markersNFTCount);　　//等于1

3.

    // Marker data has been loaded, so now load NFT data.
    if (!loadNFTData()) {
        ARLOGe("Error loading NFT data.\n");
        cleanup();
        exit(-);
    }    

newMarkers 到底是如何工作的呢？

---

# Number of markers

# Entries for each marker. Format is:
#
# Name of pattern file (relative to this file)
# Marker type (SINGLE)
# Marker width in millimetres (floating point number)
# Optional tokens:
#     FILTER [x]   Enable pose estimate filtering for the preceding marker
#                  x (optional) specifies the cutoff frequency. Default
#                  value is AR_FILTER_TRANS_MAT_CUTOFF_FREQ_DEFAULT, which
#                  at time of writing, equals 5.0.
# A blank line

../DataNFT/pinball
NFT
FILTER 15.0

 void newMarkers(const char *markersConfigDataFilePathC, ARMarkerNFT **markersNFT_out, int *markersNFTCount_out)
 {
     FILE          *fp;
     char           buf[MAXPATHLEN], buf1[MAXPATHLEN];
     int            tempI;
     ARMarkerNFT   *markersNFT;
     int            markersNFTCount;
     ARdouble       tempF;
     int            i;
     char           markersConfigDataDirC[MAXPATHLEN];
     size_t         markersConfigDataDirCLen;

     if (!markersConfigDataFilePathC || markersConfigDataFilePathC[] == '\0' || !markersNFT_out || !markersNFTCount_out) return;

     // Load the marker data file.
     ARLOGd("Opening marker config. data file from path '%s'.\n", markersConfigDataFilePathC);
     arUtilGetDirectoryNameFromPath(markersConfigDataDirC, markersConfigDataFilePathC, MAXPATHLEN, ); // 1 = add '/' at end.
     markersConfigDataDirCLen = strlen(markersConfigDataDirC);
     if ((fp = fopen(markersConfigDataFilePathC, "r")) == NULL) {
         ARLOGe("Error: unable to locate marker config data file '%s'.\n", markersConfigDataFilePathC);
         return;
     }

     // First line is number of markers to read.
     get_buff(buf, MAXPATHLEN, fp, );
     if (sscanf(buf, "%d", &tempI) !=  ) {
         ARLOGe("Error in marker configuration data file; expected marker count.\n");
         fclose(fp);
         return;
     }

     arMallocClear(markersNFT, ARMarkerNFT, tempI);
     markersNFTCount = tempI;

     ARLOGd("Reading %d marker configuration(s).\n", markersNFTCount);

 37     for (i = ; i < markersNFTCount; i++) {

         // Read marker file name.
         if (!get_buff(buf, MAXPATHLEN, fp, )) {
             ARLOGe("Error in marker configuration data file; expected marker name.\n");
             break;
         }

         // Read marker type.
         if (!get_buff(buf1, MAXPATHLEN, fp, )) {
             ARLOGe("Error in marker configuration data file; expected marker type.\n");
             break;
         }

         // Interpret marker type, and read more data.
         if (strcmp(buf1, "SINGLE") == ) {
             ARLOGe("Error in marker configuration data file; SINGLE markers not supported in this build.\n");
         } else if (strcmp(buf1, "MULTI") == ) {
             ARLOGe("Error in marker configuration data file; MULTI markers not supported in this build.\n");
         } else if (strcmp(buf1, "NFT") == ) {
             markersNFT[i].valid = markersNFT[i].validPrev = FALSE;
             arMalloc(markersNFT[i].datasetPathname, char, markersConfigDataDirCLen + strlen(buf) + );
             strcpy(markersNFT[i].datasetPathname, markersConfigDataDirC);
             strcpy(markersNFT[i].datasetPathname + markersConfigDataDirCLen, buf);
             markersNFT[i].pageNo = -;
         } else {
             ARLOGe("Error in marker configuration data file; unsupported marker type %s.\n", buf1);
         }

         // Look for optional tokens. A blank line marks end of options.
         while (get_buff(buf, MAXPATHLEN, fp, ) && (buf[] != '\0')) {
             if (strncmp(buf, "FILTER", ) == ) {
                 markersNFT[i].filterCutoffFrequency　　= AR_FILTER_TRANS_MAT_CUTOFF_FREQ_DEFAULT;
                 markersNFT[i].filterSampleRate　　　　  = AR_FILTER_TRANS_MAT_SAMPLE_RATE_DEFAULT;
                 if (strlen(buf) != ) {
                     if (sscanf(&buf[],
 #ifdef ARDOUBLE_IS_FLOAT
                                "%f"
 #else
                                "%lf"
 #endif
                                , &tempF) == ) markersNFT[i].filterCutoffFrequency = tempF;
                 }
                 markersNFT[i].ftmi = arFilterTransMatInit(markersNFT[i].filterSampleRate, markersNFT[i].filterCutoffFrequency);
             }
             // Unknown tokens are ignored.
         }
 84     }
     fclose(fp);

     // If not all markers were read, an error occurred.
     if (i < markersNFTCount) {

         // Clean up.
         for (; i >= ; i--) {
             if (markersNFT[i].datasetPathname)  free(markersNFT[i].datasetPathname);
             if (markersNFT[i].ftmi) arFilterTransMatFinal(markersNFT[i].ftmi);
         }
         free(markersNFT);

         *markersNFTCount_out = ;
         *markersNFT_out = NULL;
         return;
     }

     *markersNFTCount_out = markersNFTCount;
     *markersNFT_out      = markersNFT;
 }

typedef struct _ARMarkerNFT {
    // ARMarker protected
    bool       valid;
    bool       validPrev;
    ARdouble   trans[][];
    ARPose     pose;
    ARdouble   marker_width;
    ARdouble   marker_height;
    // ARMarker private
    ARFilterTransMatInfo *ftmi;　　// 变换矩阵，为何使用链表的形式？
    ARdouble   filterCutoffFrequency;
    ARdouble   filterSampleRate;
    // ARMarkerNFT
    int        pageNo;
    char      *datasetPathname;
} ARMarkerNFT;

loadNFTData 开始分析。

---

 // References globals: markersNFTCount
 // Modifies globals: threadHandle, surfaceSet[], surfaceSetCount, markersNFT[]
 static int loadNFTData(void)
 {
     int i;
     KpmRefDataSet *refDataSet;

     // If data was already loaded, stop KPM tracking thread and unload previously loaded data.
     if (threadHandle) {
         ARLOGi("Reloading NFT data.\n");
         unloadNFTData();
     } else {
         ARLOGi("Loading NFT data.\n");
     }

     refDataSet = NULL;

18     for (i = ; i < markersNFTCount; i++) {　　// 重点在这里！
         // (1) Load KPM data.
         KpmRefDataSet  *refDataSet2;
         ARLOGi("Reading %s.fset3\n", markersNFT[i].datasetPathname);
         if (kpmLoadRefDataSet(markersNFT[i].datasetPathname, "fset3", &refDataSet2) <  ) {
             ARLOGe("Error reading KPM data from %s.fset3\n", markersNFT[i].datasetPathname);
             markersNFT[i].pageNo = -;
             continue;
         }
         markersNFT[i].pageNo = surfaceSetCount;
         ARLOGi("  Assigned page no. %d.\n", surfaceSetCount);
         if (kpmChangePageNoOfRefDataSet(refDataSet2, KpmChangePageNoAllPages, surfaceSetCount) < ) {
             ARLOGe("Error: kpmChangePageNoOfRefDataSet\n");
             exit(-);
         }
         if (kpmMergeRefDataSet(&refDataSet, &refDataSet2) < ) {
             ARLOGe("Error: kpmMergeRefDataSet\n");
             exit(-);
         }
         ARLOGi("  Done.\n");

         // (2) Load AR2 data.
         ARLOGi("Reading %s.fset\n", markersNFT[i].datasetPathname);

         if ((surfaceSet[surfaceSetCount] = ar2ReadSurfaceSet(markersNFT[i].datasetPathname, "fset", NULL)) == NULL ) {
             ARLOGe("Error reading data from %s.fset\n", markersNFT[i].datasetPathname);
         }
         ARLOGi("  Done.\n");

         surfaceSetCount++;
         if (surfaceSetCount == PAGES_MAX) break;
49     }
     if (kpmSetRefDataSet(kpmHandle, refDataSet) < ) {
         ARLOGe("Error: kpmSetRefDataSet\n");
         exit(-);
     }
     kpmDeleteRefDataSet(&refDataSet);

     // Start the KPM tracking thread.
     threadHandle = trackingInitInit(kpmHandle);
     if (!threadHandle) exit(-);

     ARLOGi("Loading of NFT data complete.\n");
     return (TRUE);
 }

需要找个multi marker的例子再继续分析。