/* blockstat.h

Defines some structures and constants used by the blockstat
subroutines and main programs.

W H F Smith, 9 Jan 2007, version 1.  */

struct BM_DATA_IN {
	int	index;		/* identifier for BM pixel  */
	int	source_id;	/* unique file number for the source of this point value */
	short int z;	/* a depth or elevation value, neg below sea level */
	short int s;	/* combined H and V uncertainty in this z value */
};

struct BM_DATA_OUT {
	int	index;	/* range from 0 up to 933 120 000 - 1 for srtm30  */
	int	id_min;	/* source ID associated with minimum (deepest) z value */
	int	id_med;	/* source ID associated with median value */
	int	id_max;	/* source ID associated with maximum (shallowest) z value */
	short int z_min;	/* minimum (deepest) z value */
	short int z_max;	/* maximum (shallowest) z value */
	short int z_mean;	/* mean z value */
	short int z_std;	/* standard deviation of z values */
	short int z_median;	/* median z value in this block  */
	short int z_spread;	/* inter-quartile range of z in this block  */
};

struct BM_CSYS {	/* Coordinate system info  */
	double	radius;	/* Used for Mercator img only */
	double	maxlat;	/* Range of data mapped -maxlat < lat <= maxlat  */
	int	img;	/* True to use Mercator img, false for lon,lat (srtm30)  */
	int	npd;	/* # of pixels per degree (lon), that is, 30, 60, 120  */
	int	ntot;	/* nx * ny.  */
	int	nx;		/* # of pixels in 360 degrees of lon */
	int	ny;		/* # of pixels in (-maxlat, maxlat]  */
	int	nyh;	/* ny/2, used for Mercator img only.  */
};

struct BM_ERR_PARAMS {
	double	ha;
	double	hb;
	double	va;
	double	vb;
	double	smin;
	double	ha2;
	double	va2;
	double	smin2;
};

/* Definitions of macros for coordinate types:  */

#define GTOPO30 1
#define IMG1M72 2
#define IMG1M81 3
#define IMG2M72 4
#define IMG2M81 5

/* Default values for horizontal and vertical sigma a and b.
The error is computed as e = hypot(a, b*z), where z is depth.
These assume the horizontal errors are given in meters.
The vertical numbers below give half the error allowed by IHO
S-44 (1998 edition) Order 3 Bathymetric Models; the IHO standard
is a 95% confidence standard.  
SIG_H_A assumes excellent GPS navigation and SIG_H_B assumes
a beam width of 200 m in 5 km of water.  These numbers are 
probably too small. */

#define SIG_H_A 1.0
#define SIG_H_B 0.02
#define SIG_V_A 2.5
#define SIG_V_B 0.025

/* SIG_Z_MIN is used to set a minimum, positive uncertainty
in depth if the computed uncertainty comes out too small. */

#define SIG_Z_MIN 1.0

/* NSX, NSY, NST are the X Y and Total dimensions of the 
one byte per pixel, global lat lon one arc minute file
of seafloor slopes to use in converting horizontal uncertainties
to vertical uncertainties.  */ 

#define NSX 21600
#define NSY 10800
#define NST 233280000

int     lonlat_from_k (int k, double *lon, double *lat, struct BM_CSYS *coords);
int     k_from_lonlat (double lon, double lat, struct BM_CSYS *coords);
int     init_coords (struct BM_CSYS *coords, int coord_type);
void	init_default_err_p (struct BM_ERR_PARAMS *err_p);
int		square_err_a (struct BM_ERR_PARAMS *err_p);
FILE *get_next_fp (int stdin_is_list, int argc, char **argv, int *nargfiles, int *karg, FILE *fplist, FILE *lastfp);
int		load_slopes (FILE *fp, unsigned char *sfslope);
void	dat2bmdi (double x, double y, double z, double sh, double sv, int srcid, 
	unsigned char *sfslope, struct BM_ERR_PARAMS *err_p, struct BM_CSYS *coords, struct BM_DATA_IN *bmdi);
int	process_cm_record (char *strbuf, unsigned char *sfslope, struct BM_ERR_PARAMS *err_p, struct BM_CSYS *coords, struct BM_DATA_IN *bmdi);