/**
 * \file view.c
 *
 * \brief GIS Library - 3D View functions.
 *
 * (C) 2001-2008 by the GRASS Development Team
 *
 * This program is free software under the GNU General Public License
 * (>=v2). Read the file COPYING that comes with GRASS for details.
 *
 * \author Bill Brown - US Army CERL
 *
 * \date 1992-2008
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <grass/gis.h>
#include <grass/glocale.h>


#define REQ_KEYS 8

static int compare_wind(const struct Cell_head *, const struct Cell_head *);
static int get_bool(const char *);
static void pr_winerr(int, const char *);
static void edge_sort(float sides[4]);
static int read_old_format(struct G_3dview *, FILE *);

static const int vers_major = 4;
static const int vers_minor = 1;

static int Suppress_warn = 0;


/**
 * \brief Turns 3D View warnings on and off.
 *
 * If Suppress_warn is 0, a warning will be printed if less than 95% of
 * the window when the view was saved overlaps the current window.
 *
 * \param[in] b
 * \return
 */

void G_3dview_warning(int b)
{
    Suppress_warn = b ? 0 : 1;
}


/**
 * \brief Sets default for <b>v</b> based on <b>w</b>.
 *
 * \param[in,out] v
 * \param[in] w
 * \return always returns 1
 */

int G_get_3dview_defaults(struct G_3dview *v, struct Cell_head *w)
{
    if (!v || !w)
	return (-1);

    v->exag = 1.0;
    v->fov = 40.0;
    v->from_to[0][0] = (w->east + w->west) / 2.0;
    v->from_to[0][1] = w->south - (w->north - w->south);
    v->from_to[0][2] = w->north - w->south;
    v->from_to[1][0] = (w->east + w->west) / 2.0;
    v->from_to[1][1] = (w->north + w->south) / 2.0;
    v->from_to[1][2] = 0.0;

    v->twist = 0.0;
    v->mesh_freq = 15;
    v->poly_freq = 1;
    v->display_type = 2;
    v->colorgrid = v->fringe = v->surfonly = v->lightson = v->doavg = 0;
    v->dozero = v->shading = 1;
    strcpy(v->bg_col, "black");
    strcpy(v->grid_col, "white");
    strcpy(v->other_col, "red");
    v->ambient = v->shine = 0.3;
    v->lightcol[0] = v->lightcol[1] = v->lightcol[2] = 0.8;
    v->lightpos[0] = w->west;
    v->lightpos[1] = w->north;
    v->lightpos[2] = (w->east - w->west) / 2.0;
    v->lightpos[3] = 1.0;	/* local source */

    v->vwin.north = w->north;
    v->vwin.south = w->south;
    v->vwin.east = w->east;
    v->vwin.west = w->west;
    v->vwin.format = w->format;
    v->vwin.compressed = w->compressed;
    v->vwin.proj = w->proj;
    v->vwin.zone = w->zone;
    v->vwin.ew_res = w->ew_res;
    v->vwin.ns_res = w->ns_res;
    v->vwin.cols = w->cols;
    v->vwin.rows = w->rows;

    return (1);

}


/**
 * \brief Saves info to a 3d.view file.
 *
 * The address of a window (struct Cell_head *) may be passed, or if 
 * NULL is passed, the Cell_head structure inside the G_3dview struct 
 * will be used.  e.g., if you called <i>G_get_3dview_defaults</i> with 
 * the Cell_head you want saved, the G_3dview returned already contains 
 * the new Cell_head. But if you're using all the keywords, so didn't 
 * need defaults, pass this routine the address of a Cell_head.<br>
 *
 * User should call <i>G_get_3dview_defaults</i> before filling a 
 * G_3dview struct to be written if not using all of the optional 
 * keywords.<br>
 *
 * These keywords are constant in all 3d.view files:<br>
 * PGM_ID<br>
 * <b>cell keywords:</b><br>
 * north<br>
 * south<br>
 * east<br>
 * west<br>
 * rows<br>
 * cols<br>
 * <b>required keywords:</b><br>
 * TO_EASTING<br>
 * TO_NORTHING<br>
 * TO_HEIGHT<br>
 * FROM_EASTING<br>
 * FROM_NORTHING<br>
 * FROM_HEIGHT<br>
 * Z_EXAG<br>
 * FIELD_VIEW<br>
 * <b>optional keywords:</b> (defaults provided when reading)<br>
 * TWIST<br>
 * MESH_FREQ<br>
 * POLY_RES<br>
 * DOAVG<br>
 * DISPLAY_TYPE<br>
 * DOZERO<br>
 * COLORGRID<br>
 * SHADING<br>
 * FRINGE<br>
 * BG_COL<br>
 * GRID_COL<br>
 * OTHER_COL<br>
 * LIGHTS_ON<br>
 * LIGHTPOS<br>
 * LIGHTCOL<br>
 * LIGHTAMBIENT<br>
 * SHINE<br>
 * SURFACEONLY<br>
 *
 * \param[in] fname file name
 * \param[in] mapset
 * \param[in] View
 * \param[in] Win
 * \return 1 on success
 * \return -1 on error
 */

int G_put_3dview(const char *fname, const char *mapset,
		 const struct G_3dview *View, const struct Cell_head *Win)
{
    FILE *fp;

    if (NULL == (fp = G_fopen_new("3d.view", fname))) {
	G_warning(_("Unable to open %s for writing"), fname);
	return (-1);
    }

    fprintf(fp, "# %01d.%02d\n", vers_major, vers_minor);
    fprintf(fp, "PGM_ID: %s\n", View->pgm_id);

    if (Win) {
	fprintf(fp, "north: %f\n", Win->north);
	fprintf(fp, "south: %f\n", Win->south);
	fprintf(fp, "east: %f\n", Win->east);
	fprintf(fp, "west: %f\n", Win->west);
	fprintf(fp, "rows: %d\n", Win->rows);
	fprintf(fp, "cols: %d\n", Win->cols);
    }
    else {
	fprintf(fp, "north: %f\n", View->vwin.north);
	fprintf(fp, "south: %f\n", View->vwin.south);
	fprintf(fp, "east: %f\n", View->vwin.east);
	fprintf(fp, "west: %f\n", View->vwin.west);
	fprintf(fp, "rows: %d\n", View->vwin.rows);
	fprintf(fp, "cols: %d\n", View->vwin.cols);
    }

    fprintf(fp, "TO_EASTING: %f\n", View->from_to[1][0]);
    fprintf(fp, "TO_NORTHING: %f\n", View->from_to[1][1]);
    fprintf(fp, "TO_HEIGHT: %f\n", View->from_to[1][2]);
    fprintf(fp, "FROM_EASTING: %f\n", View->from_to[0][0]);
    fprintf(fp, "FROM_NORTHING: %f\n", View->from_to[0][1]);
    fprintf(fp, "FROM_HEIGHT: %f\n", View->from_to[0][2]);
    fprintf(fp, "Z_EXAG: %f\n", View->exag);
    fprintf(fp, "TWIST: %f\n", View->twist);
    fprintf(fp, "FIELD_VIEW: %f\n", View->fov);
    fprintf(fp, "MESH_FREQ: %d\n", View->mesh_freq);
    fprintf(fp, "POLY_RES: %d\n", View->poly_freq);
    fprintf(fp, "DOAVG: %d\n", View->doavg);
    fprintf(fp, "DISPLAY_TYPE: %d\n", View->display_type);
    fprintf(fp, "DOZERO: %d\n", View->dozero);

    fprintf(fp, "COLORGRID: %d\n", View->colorgrid);	/* 1 = use color */
    fprintf(fp, "SHADING: %d\n", View->shading);
    fprintf(fp, "FRINGE: %d\n", View->fringe);
    fprintf(fp, "BG_COL: %s\n", View->bg_col);
    fprintf(fp, "GRID_COL: %s\n", View->grid_col);
    fprintf(fp, "OTHER_COL: %s\n", View->other_col);
    fprintf(fp, "SURFACEONLY: %d\n", View->surfonly);
    fprintf(fp, "LIGHTS_ON: %d\n", View->lightson);
    fprintf(fp, "LIGHTPOS: %f %f %f %f\n", View->lightpos[0],
	    View->lightpos[1], View->lightpos[2], View->lightpos[3]);
    fprintf(fp, "LIGHTCOL: %f %f %f\n", View->lightcol[0], View->lightcol[1],
	    View->lightcol[2]);
    fprintf(fp, "LIGHTAMBIENT: %f\n", View->ambient);
    fprintf(fp, "SHINE: %f\n", View->shine);

    fclose(fp);

    return (1);
}


/**
 * \brief Gets a 3D View.
 *
 * If reading an old format, the window boundaries are not checked 
 * against the current window since boundaries weren't saved.
 *
 * \param[in] fname
 * \param[in] mapset
 * \param[in,out] View
 * \return -1 on error
 * \return 1 on success
 * \return 2 if <b>fname</b> was written with this version of routine
 * \return 0 if is older format (through 4.0)
 */

int G_get_3dview(const char *fname, const char *mapset, struct G_3dview *View)
{
    struct Cell_head curwin;
    FILE *fp;
    char buffer[80], keystring[24], boo[8], nbuf[128], ebuf[128];
    int lap, v_maj, v_min, wind_keys = 0, reqkeys = 0;
    int current = 0;		/* current version flag */

    mapset = G_find_file2("3d.view", fname, mapset);
    if (mapset != NULL) {
	if (NULL == (fp = G_fopen_old("3d.view", fname, mapset))) {
	    G_warning(_("Unable to open %s for reading"), fname);
	    return (-1);
	}

	G_get_set_window(&curwin);
	G_get_3dview_defaults(View, &curwin);

	if (NULL != fgets(buffer, 80, fp)) {
	    if (buffer[0] != '#') {	/* old d.3d format */
		rewind(fp);
		if (0 <= read_old_format(View, fp))
		    return (0);
		else
		    return (-1);
	    }
	    else {
		sscanf(buffer, "#%d.%d\n", &v_maj, &v_min);
		if (v_maj == vers_major && v_min == vers_minor)
		    current = 1;	/* same version */
	    }
	}

	while (NULL != fgets(buffer, 75, fp)) {
	    if (buffer[0] != '#') {

		sscanf(buffer, "%[^:]:", keystring);

		if (!strcmp(keystring, "PGM_ID")) {
		    sscanf(buffer, "%*s%s", (View->pgm_id));
		    continue;
		}
		if (!strcmp(keystring, "north")) {
		    sscanf(buffer, "%*s%lf", &(View->vwin.north));
		    ++wind_keys;
		    continue;
		}
		if (!strcmp(keystring, "south")) {
		    sscanf(buffer, "%*s%lf", &(View->vwin.south));
		    ++wind_keys;
		    continue;
		}
		if (!strcmp(keystring, "east")) {
		    sscanf(buffer, "%*s%lf", &(View->vwin.east));
		    ++wind_keys;
		    continue;
		}
		if (!strcmp(keystring, "west")) {
		    sscanf(buffer, "%*s%lf", &(View->vwin.west));
		    ++wind_keys;
		    continue;
		}
		if (!strcmp(keystring, "rows")) {
		    sscanf(buffer, "%*s%d", &(View->vwin.rows));
		    ++wind_keys;
		    continue;
		}
		if (!strcmp(keystring, "cols")) {
		    sscanf(buffer, "%*s%d", &(View->vwin.cols));
		    ++wind_keys;
		    continue;
		}
		if (!strcmp(keystring, "TO_EASTING")) {
		    sscanf(buffer, "%*s%f", &(View->from_to[1][0]));
		    ++reqkeys;
		    continue;
		}
		if (!strcmp(keystring, "TO_NORTHING")) {
		    sscanf(buffer, "%*s%f", &(View->from_to[1][1]));
		    ++reqkeys;
		    continue;
		}
		if (!strcmp(keystring, "TO_HEIGHT")) {
		    sscanf(buffer, "%*s%f", &(View->from_to[1][2]));
		    ++reqkeys;
		    continue;
		}
		if (!strcmp(keystring, "FROM_EASTING")) {
		    sscanf(buffer, "%*s%f", &(View->from_to[0][0]));
		    ++reqkeys;
		    continue;
		}
		if (!strcmp(keystring, "FROM_NORTHING")) {
		    sscanf(buffer, "%*s%f", &(View->from_to[0][1]));
		    ++reqkeys;
		    continue;
		}
		if (!strcmp(keystring, "FROM_HEIGHT")) {
		    sscanf(buffer, "%*s%f", &(View->from_to[0][2]));
		    ++reqkeys;
		    continue;
		}
		if (!strcmp(keystring, "Z_EXAG")) {
		    sscanf(buffer, "%*s%f", &(View->exag));
		    ++reqkeys;
		    continue;
		}
		if (!strcmp(keystring, "MESH_FREQ")) {
		    sscanf(buffer, "%*s%d", &(View->mesh_freq));
		    continue;
		}
		if (!strcmp(keystring, "POLY_RES")) {
		    sscanf(buffer, "%*s%d", &(View->poly_freq));
		    continue;
		}
		if (!strcmp(keystring, "DOAVG")) {
		    sscanf(buffer, "%*s%d", &(View->doavg));
		    continue;
		}
		if (!strcmp(keystring, "FIELD_VIEW")) {
		    sscanf(buffer, "%*s%f", &(View->fov));
		    ++reqkeys;
		    continue;
		}
		if (!strcmp(keystring, "TWIST")) {
		    sscanf(buffer, "%*s%f", &(View->twist));
		    continue;
		}
		if (!strcmp(keystring, "DISPLAY_TYPE")) {
		    sscanf(buffer, "%*s%d", &View->display_type);
		    continue;
		}
		if (!strcmp(keystring, "DOZERO")) {
		    sscanf(buffer, "%*s%s", boo);
		    View->dozero = get_bool(boo);
		    continue;
		}
		if (!strcmp(keystring, "COLORGRID")) {
		    sscanf(buffer, "%*s%s", boo);
		    View->colorgrid = get_bool(boo);
		    continue;
		}
		if (!strcmp(keystring, "FRINGE")) {
		    sscanf(buffer, "%*s%s", boo);
		    View->fringe = get_bool(boo);
		    continue;
		}
		if (!strcmp(keystring, "SHADING")) {
		    sscanf(buffer, "%*s%s", boo);
		    View->shading = get_bool(boo);
		    continue;
		}
		if (!strcmp(keystring, "BG_COL")) {
		    sscanf(buffer, "%*s%s", View->bg_col);
		    continue;
		}
		if (!strcmp(keystring, "GRID_COL")) {
		    sscanf(buffer, "%*s%s", View->grid_col);
		    continue;
		}
		if (!strcmp(keystring, "OTHER_COL")) {
		    sscanf(buffer, "%*s%s", View->other_col);
		    continue;
		}
		if (!strcmp(keystring, "SURFACEONLY")) {
		    sscanf(buffer, "%*s%s", boo);
		    View->surfonly = get_bool(boo);
		    continue;
		}
		if (!strcmp(keystring, "LIGHTS_ON")) {
		    sscanf(buffer, "%*s%s", boo);
		    View->lightson = get_bool(boo);
		    continue;
		}
		if (!strcmp(keystring, "LIGHTPOS")) {
		    sscanf(buffer, "%*s%f%f%f%f", &(View->lightpos[0]),
			   &(View->lightpos[1]), &(View->lightpos[2]),
			   &(View->lightpos[3]));
		    continue;
		}
		if (!strcmp(keystring, "LIGHTCOL")) {
		    sscanf(buffer, "%*s%f%f%f", &(View->lightcol[0]),
			   &(View->lightcol[1]), &(View->lightcol[2]));
		    continue;
		}
		if (!strcmp(keystring, "LIGHTAMBIENT")) {
		    sscanf(buffer, "%*s%f", &(View->ambient));
		    continue;
		}
		if (!strcmp(keystring, "SHINE")) {
		    sscanf(buffer, "%*s%f", &(View->shine));
		    continue;
		}
	    }
	}

	fclose(fp);

	if (reqkeys != REQ_KEYS)	/* required keys not found */
	    return (-1);

	/* fill rest of View->vwin */
	if (wind_keys == 6) {
	    View->vwin.ew_res = (View->vwin.east - View->vwin.west) /
		View->vwin.cols;
	    View->vwin.ns_res = (View->vwin.north - View->vwin.south) /
		View->vwin.rows;
	}
	else
	    return (0);		/* older format */

	if (!Suppress_warn) {
	    if (95 > (lap = compare_wind(&(View->vwin), &curwin))) {

		fprintf(stderr, _("GRASS window when view was saved:\n"));
		G_format_northing(View->vwin.north, nbuf, G_projection());
		fprintf(stderr, "north:   %s\n", nbuf);
		G_format_northing(View->vwin.south, nbuf, G_projection());
		fprintf(stderr, "south:   %s\n", nbuf);
		G_format_easting(View->vwin.east, ebuf, G_projection());
		fprintf(stderr, "east:    %s\n", ebuf);
		G_format_easting(View->vwin.west, ebuf, G_projection());
		fprintf(stderr, "west:    %s\n", ebuf);
		pr_winerr(lap, fname);
	    }
	}
    }
    else {
	G_warning(_("Unable to open %s for reading"), fname);
	return (-1);
    }

    if (current)
	return (2);

    return (1);
}


/* returns the percentage of savedwin that overlaps curwin */

static int compare_wind(const struct Cell_head *savedwin,
			const struct Cell_head *curwin)
{
    float e_ings[4], n_ings[4], area_lap, area_saved;
    int outside = 0;

    if (savedwin->north < curwin->south)
	outside = 1;
    if (savedwin->south > curwin->north)
	outside = 1;
    if (savedwin->east < curwin->west)
	outside = 1;
    if (savedwin->west > curwin->east)
	outside = 1;
    if (outside)
	return (0);

    e_ings[0] = savedwin->west;
    e_ings[1] = savedwin->east;
    e_ings[2] = curwin->west;
    e_ings[3] = curwin->east;
    edge_sort(e_ings);

    n_ings[0] = savedwin->south;
    n_ings[1] = savedwin->north;
    n_ings[2] = curwin->south;
    n_ings[3] = curwin->north;
    edge_sort(n_ings);

    area_lap = (e_ings[2] - e_ings[1]) * (n_ings[2] - n_ings[1]);
    area_saved = (savedwin->east - savedwin->west) *
	(savedwin->north - savedwin->south);

    return ((int)(area_lap * 100.0 / area_saved));
}


static int get_bool(const char *str)
{
    if (str[0] == 'y' || str[0] == 'Y')
	return (1);
    if (str[0] == 'n' || str[0] == 'N')
	return (0);

    return (atoi(str) ? 1 : 0);
}


static void pr_winerr(int vis,	/* % of saved window overlapping current window */
		      const char *viewname)
{
    switch (vis) {
    case 0:
	G_warning(_(" Window saved in \"%s\" is completely outside of current GRASS window."),
		  viewname);
	break;
    default:
	G_warning(_(" Only %d%% of window saved in \"%s\" overlaps with current GRASS window."),
		  vis, viewname);
	break;
    }
}

/*********************************************************************/
/* sorts 4 floats from lowest to highest */

static void edge_sort(float sides[4])
{
    int i, j;
    float temp;

    for (i = 0; i < 4; ++i) {
	for (j = i + 1; j < 4; ++j) {
	    if (sides[j] < sides[i]) {	/* then swap */
		temp = sides[i];
		sides[i] = sides[j];
		sides[j] = temp;
	    }
	}
    }
}


static int read_old_format(struct G_3dview *v, FILE * fp)
{
    char buffer[80];
    int req_keys = 0;
    double td;
    char boo[8];

    strcpy((v->pgm_id), "d.3d");
    if (1 == sscanf(fgets(buffer, 80, fp), "%f", &(v->from_to[1][0])))
	++req_keys;
    if (1 == sscanf(fgets(buffer, 80, fp), "%f", &(v->from_to[1][1])))
	++req_keys;
    if (1 == sscanf(fgets(buffer, 80, fp), "%f", &(v->from_to[1][2])))
	++req_keys;
    if (1 == sscanf(fgets(buffer, 80, fp), "%f", &(v->from_to[0][0])))
	++req_keys;
    if (1 == sscanf(fgets(buffer, 80, fp), "%f", &(v->from_to[0][1])))
	++req_keys;
    if (1 == sscanf(fgets(buffer, 80, fp), "%f", &(v->from_to[0][2])))
	++req_keys;
    if (1 == sscanf(fgets(buffer, 80, fp), "%f", &(v->exag)))
	++req_keys;
    sscanf(fgets(buffer, 80, fp), "%d", &(v->mesh_freq));
    if (1 == sscanf(fgets(buffer, 80, fp), "%f", &(v->fov)))
	++req_keys;
    if (1 == sscanf(fgets(buffer, 80, fp), "%lf", &td)) {	/* resolution */
	v->vwin.rows = (v->vwin.north - v->vwin.south) / td;
	v->vwin.cols = (v->vwin.east - v->vwin.west) / td;
	v->vwin.ew_res = v->vwin.ns_res = td;
    }

    sscanf(fgets(buffer, 80, fp), "%s", boo);	/* linesonly */
    v->display_type = get_bool(boo) ? 1 : 3;
    sscanf(fgets(buffer, 80, fp), "%s", boo);
    v->dozero = get_bool(boo);
    sscanf(fgets(buffer, 80, fp), "%s", v->grid_col);
    if (!strcmp(v->grid_col, "color"))
	v->colorgrid = 1;

    sscanf(fgets(buffer, 80, fp), "%s", v->other_col);
    sscanf(fgets(buffer, 80, fp), "%s", v->bg_col);
    sscanf(fgets(buffer, 80, fp), "%s", boo);
    v->doavg = get_bool(boo);

    if (v->exag) {		/* old 3d.view files saved height with no exag */
	v->from_to[0][2] /= v->exag;
	v->from_to[1][2] /= v->exag;
    }


    fclose(fp);
    if (req_keys == REQ_KEYS)
	return (1);
    else
	return (-1);
}