misr_init.cc

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// The code in this file is adopted from A.7.2 of MISR data products specifications 
// Revision S
// https://eosweb.larc.nasa.gov/sites/default/files/project/misr/DPS_v50_RevS.pdf)
//
#ifdef USE_HDFEOS2_LIB
#include "misrproj.h" /* Prototype for this function */
#include "errormacros.h" /* Error macros */
int nb;
int nl;
int ns;
float absOffset[NBLOCK];
float relOffset[NBLOCK-1];
double ulc[2];
double lrc[2];
double sx;
double sy;
double xc;
double yc;
#define FUNC_NAMEm "misr_init"
int misr_init(
    const int nblock, /* Number of blocks */
    const int nline, /* Number of lines in a block */
    const int nsample, /* Number of samples in a block */
    const float relOff[NOFFSET],/* Block offsets */

    const double ulc_coord[], /* Upper left corner coord. in meters */
    const double lrc_coord[] /* Lower right corner coord. in meters */
)
{
    int i; /* Offset index */
    char msg[STRLEN]; /* Warning message */
    /* Argument checks */
    if (nblock < 1 || nblock > NBLOCK) {
        sprintf(msg,"nblock is out of range (1 < %d < %d)", nblock, NBLOCK);
        WRN_LOG_JUMP(msg);
    }
    /* Convert relative offsets to absolute offsets */
    absOffset[0] = 0.0;
    for (i = 1; i < NBLOCK; i++) {
        absOffset[i] = absOffset[i-1] + relOff[i-1];
        relOffset[i-1] = relOff[i-1];
    }
    /* Set ulc and lrc SOM coordinates */
    /* Note; ulc y and lrc y are reversed in the structural metadata. */
    ulc[0] = ulc_coord[0];
    ulc[1] = lrc_coord[1];
    lrc[0] = lrc_coord[0];
    lrc[1] = ulc_coord[1];
    /* Set number of blocks, lines and samples */
    nb = nblock;
    nl = nline;
    ns = nsample;
    /* Compute pixel size in ulc/lrc units (meters) */
    sx = (lrc[0] - ulc[0]) / nl;
    sy = (lrc[1] - ulc[1]) / ns;
    /* Adjust ulc to be in the center of the pixel */
    xc = ulc[0] + sx / 2.0;
    yc = ulc[1] + sy / 2.0;
    return(0);
ERROR_HANDLE:
    return(1);
}
#endif