/* MX LIBRARY FUNCTION:  mxiraf_image_s_open_f3
 *
 * PURPOSE:  Open a IRAF image (open a mxiraf_image_s structure). 
 *
 * USAGE EXAMPLES:
 *
 *   struct mxiraf_image_s *m31=NULL;
 *   struct mxiraf_image_s *m33=NULL;
 *   int status;
 *   
 *   status = mxiraf_image_s_open_f3 (&m31, "m31.fits", IRAF_READ_WRITE);
 *   status = mxiraf_image_s_open_f3 (&m33, "m33.fits", IRAF_READ_ONLY);
 *
 * AUTHOR:  K. J. Mighell (mighell@noao.edu)
 *
 * LANGUAGE:  ANSI C
 *
 * DOCUMENTATION:  http://www.noao.edu/staff/mighell/mx
 *
 * DATE:  20000313
 *
 * MOD:  3
 * 
 * Copyleft (L) 2000 Kenneth John Mighell
 */

#include "mx.h" 

int mxiraf_image_s_open_f3( 
  struct mxiraf_image_s **out,
  char *name,
  IRAFIOMode iomode
) {

  char mxfunc[] = "mxiraf_image_s_open_f3";
  int status;

  struct mxiraf_image_s *image=NULL;
  int   magic_offset;
  int   ix;
  int   ix0;
  int   iy;
  int   iy0;
  int   iy1;
  int   pxi;
  int   mpx;
  int   offset;
  int   nx;
  int   ny;
  int   idx0;
  int   idy0;
  float *r4px;

  /*
   * Allocate memory for new mxiraf_image_s structure
   */
  image = (struct mxiraf_image_s *)malloc(sizeof(struct mxiraf_image_s));
  /*
   * any errors?
   */
  if ((struct mxiraf_image_s *)NULL==image) {
    status = 1;
    sprintf (MX.tmpmsg,
      "#   could not allocate mxiraf_image_s structure!\n"
    );
    goto error;
  }

  /*
   * Set image-> name to name
   */
  strncpy (image->name, name, sizeof(image->name));

  /*
   * Set image->iomode to iomode
   */
  image->iomode = iomode;

  /*
   * Open the input IRAF image 
   */
  image->ptr = c_immap (image->name, image->iomode, 0);
  /* CVOS error? */
  if ( mxiraf_cvos_error_check_f0() ) {status = 2; goto error2;}

  /* 
   * Get image section 
   */
  c_imgsection (image->name, image->section, sizeof(image->name));
  /* CVOS error? */
  if ( mxiraf_cvos_error_check_f0() ) {status = 3; goto error2;}

  /* 
   * Get the image dimensions 
   */
  image->ndimi = c_imgndim (image->ptr);
  /* CVOS error? */
  if ( mxiraf_cvos_error_check_f0() ) {status = 4; goto error2;}
  /* only 2 dimensions are currently supported */
  if (image->ndimi != 2) {
    status = 5;
    sprintf (
      MX.tmpmsg,
      "#   image->ndimi=%d != 2  <-- Only 2 dimensions currently supported\n",
      image->ndimi
    );
    goto error;
  }

  /* 
   * Get the size of the X dimension (width)
   */
  nx = c_imglen (image->ptr, 1);
  /* CVOS error? */
  if ( mxiraf_cvos_error_check_f0() ) {status = 6; goto error2;}
  /* 
   * Set image->NXI to nx;
   */
  image->NXI = nx;


  /* 
   * Get the size of the Y dimension (height)
   */
  ny = c_imglen (image->ptr, 2);
  /* CVOS error? */
  if ( mxiraf_cvos_error_check_f0() ) {status = 7; goto error2;}
  /* 
   * Set image->NYI to ny;
   */
  image->NYI = ny;

  /* 
   * Get the pixel type
   */
  image->pxtype = (IRAFType) c_imgtypepix (image->ptr);
  /* CVOS error? */
  if ( mxiraf_cvos_error_check_f0() ) {status = 8; goto error2;}
  /* only IRAF_REAL (TY_REAL) data is currently supported */
  if (image->pxtype != IRAF_REAL) {
    status = 9;
    sprintf (
      MX.tmpmsg,
      "#   image->pxtype=%d != %d  "
      "<-- Only IRAF_REAL (TY_REAL) currently supported\n",
      image->pxtype, (IRAF_REAL)
    );
    goto error;
  } 

  /* 
   * Get offsets 
   */
  /* HACK ALERT: begin ========================================================
   */
  magic_offset = 49 - 208; /* IM_VOFF - IM_LEN */
  idx0 = c_imglen (image->ptr, (1+magic_offset) );
  /* CVOS error? */
  if ( mxiraf_cvos_error_check_f0() ) {status = 10; goto error2;}
  /*
   * Set image->LLX0I to idx0
   */
  image->LLX0I = idx0;
  idy0 = c_imglen (image->ptr, (2+magic_offset) );
  /* CVOS error? */
  if ( mxiraf_cvos_error_check_f0() ) {status = 11; goto error2;}
  /*
   * Set image->LLY0I to idy0
   */
  image->LLY0I = idy0;
  /*
   * Use of magic_offset is a temporary hack until such time 
   * that CVOS truely becomes a full C implementation of VOS
   *
   * HACK ALERT: end ==========================================================
   */

  /*
   * Open mxip_image_s structure
   */
  mpx = 1;
  status = mxip_image_s_open_f7(
    &image->data,
    image->NXI,
    image->NYI,
    image->LLX0I,
    image->LLY0I,
    mpx,
    image->name
  );
  if (status) {
    status = 12;
    goto error2;
  } 

  /*
   * The image->data->vectord has been initialized to zero.
   * Now copy the pixel data.
   */
  for (iy0 = 0; iy0 < ny; ++iy0) { 
    iy1 = iy0 + 1;
    r4px = c_imgl2r (image->ptr, iy1);        /* get data row by row */
    /* CVOS error? */
    if ( mxiraf_cvos_error_check_f0() ) {status = 13; goto error2;}
    offset = iy0*nx;
    for (ix0 = 0; ix0 < nx; ++ix0) {  
      pxi = offset + ix0;                      /* calculate offset */
      image->data->vectord[pxi] = (double) r4px[ix0]; 
                                               /* get pixels one by one */
    }
  }

  image->openedi = MX_OPENED;

ok:
  status = 0;
  goto bye;

error:
  mxp_errmsg_set_f3 (mxfunc, status, MX.tmpmsg);
  goto bye;

error2:
  mxp_errmsg_append_f3 (mxfunc, status, "");
  goto bye;

bye:
  *out = &*image;
  return (status);

}
/* end-of-file */