Geografic-Information-System/lib/raster/color_read.c

/*!
 * \file raster/color_read.c
 * 
 * \brief Raster Library - Read color table of raster map
 *
 * (C) 1999-2009 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 USACERL and many others
 */

#include <string.h>

#include <grass/gis.h>
#include <grass/raster.h>
#include <grass/glocale.h>

static int read_colors(const char *, const char *, const char *,
		       struct Colors *);
static int read_new_colors(FILE *, struct Colors *);
static int read_old_colors(FILE *, struct Colors *);


/*!
 * \brief Read raster map layer color table
 *
 * The color table for the raster map <i>name</i> in the specified
 * <i>mapset</i> is read into the <i>colors</i> structure. If the data
 * layer has no color table, a default color table is generated and 0
 * is returned. If there is an error reading the color table, a
 * diagnostic message is printed and -1 is returned. If the color
 * table is read ok, 1 is returned.
 *
 * This routine reads the rules from the color file. If the input
 * raster map is is a floating-point map it calls
 * Rast_mark_colors_as_fp().
 *
 *  Note: If a secondary color file for map name <i>name</i> exists in
 *  the current project, that color file is read.  This allows the
 *  user to define their own color lookup tables for cell maps found
 *  in other mapsets.
 *
 *  Warning message is printed if the color file is
 *  missing or invalid.
 *
 * \param name map name
 * \param mapset mapset name
 * \param[out] colors pointer to Colors structure
 *
 * \return -1 on error
 * \return 0 if missing, but default colors generated
 * \return 1 on success
 */
int Rast_read_colors(const char *name, const char *mapset,
		     struct Colors *colors)
{
    int fp;
    char buf[GNAME_MAX];
    char *err;
    char xname[GNAME_MAX];
    struct Range range;
    struct FPRange drange;
    CELL min, max;
    DCELL dmin, dmax;

    fp = Rast_map_is_fp(name, mapset);
    Rast_init_colors(colors);

    strcpy(xname, name);
    mapset = G_find_raster(xname, mapset);
    name = xname;

    if (fp)
	Rast_mark_colors_as_fp(colors);

    /* first look for secondary color table in current mapset */
    sprintf(buf, "colr2/%s", mapset);
    if (read_colors(buf, name, G_mapset(), colors) >= 0)
	return 1;

    /* now look for the regular color table */
    switch (read_colors("colr", name, mapset, colors)) {
    case -2:
	if (!fp) {
	    if (Rast_read_range(name, mapset, &range) >= 0) {
		Rast_get_range_min_max(&range, &min, &max);
		if (!Rast_is_c_null_value(&min) &&
		    !Rast_is_c_null_value(&max))
		    Rast_make_rainbow_colors(colors, min, max);
		return 0;
	    }
	}
	else {
	    if (Rast_read_fp_range(name, mapset, &drange) >= 0) {
		Rast_get_fp_range_min_max(&drange, &dmin, &dmax);
		if (!Rast_is_d_null_value(&dmin) &&
		    !Rast_is_d_null_value(&dmax))
		    Rast_make_rainbow_fp_colors(colors, dmin, dmax);
		return 0;
	    }
	}
	err = _("missing");
	break;
    case -1:
	err = _("invalid");
	break;
    default:
	return 1;
    }

    G_warning(_("Color support for <%s@%s> %s"), name, mapset, err);
    return -1;
}

static int read_colors(const char *element, const char *name,
		       const char *mapset, struct Colors *colors)
{
    FILE *fd;
    int stat;
    char buf[1024];

    if (!(fd = G_fopen_old(element, name, mapset)))
	return -2;

    /*
     * first line in 4.0 color files is %
     * otherwise it is pre 4.0
     */
    if (fgets(buf, sizeof buf, fd) == NULL) {
	fclose(fd);
	return -1;
    }
    G_fseek(fd, 0L, 0);

    G_strip(buf);
    if (*buf == '%') {		/* 4.0 format */
	stat = read_new_colors(fd, colors);
	colors->version = 0;	/* 4.0 format */
    }
    else {
	stat = read_old_colors(fd, colors);
	colors->version = -1;	/* pre 4.0 format */
    }
    fclose(fd);
    return stat;
}

/* parse input lines with the following formats
 *   val1:r:g:b val2:r:g:b
 *   val:r:g:b          (implies cat1==cat2)
 *
 * r:g:b can be just a single grey level
 *   cat1:x cat2:y
 *   cat:x
 *
 * optional lines are
 *    invert            invert color table
 *    shift:n           where n is the amount to shift the color table
 *    nv:r:g:b          color to use for NULL values
 *    *:r:g:b           color to use for undefined (beyond color rules)
 */
static int read_new_colors(FILE * fd, struct Colors *colors)
{
    double val1, val2;
    long cat1, cat2;
    int r1, g1, b1;
    int r2, g2, b2;
    char buf[1024];
    char word1[256], word2[256];
    int n, fp_rule;
    int null, undef;
    int modular;
    DCELL shift;

    if (fgets(buf, sizeof buf, fd) == NULL)
	return -1;
    G_strip(buf);

    if (sscanf(buf + 1, "%lf %lf", &val1, &val2) == 2)
	Rast_set_d_color_range((DCELL) val1, (DCELL) val2, colors);

    modular = 0;
    while (fgets(buf, sizeof buf, fd)) {
	null = undef = fp_rule = 0;
	*word1 = *word2 = 0;
	n = sscanf(buf, "%s %s", word1, word2);
	if (n < 1)
	    continue;

	if (sscanf(word1, "shift:%lf", &shift) == 1
	    || (strcmp(word1, "shift:") == 0 &&
		sscanf(word2, "%lf", &shift) == 1)) {
	    Rast_shift_d_colors(shift, colors);
	    continue;
	}
	if (strcmp(word1, "invert") == 0) {
	    Rast_invert_colors(colors);
	    continue;
	}
	if (strcmp(word1, "%%") == 0) {
	    modular = !modular;
	    continue;
	}

	switch (sscanf(word1, "nv:%d:%d:%d", &r1, &g1, &b1)) {
	case 1:
	    null = 1;
	    b1 = g1 = r1;
	    break;
	case 3:
	    null = 1;
	    break;
	}
	if (!null)
	    switch (sscanf(word1, "*:%d:%d:%d", &r1, &g1, &b1)) {
	    case 1:
		undef = 1;
		b1 = g1 = r1;
		break;
	    case 3:
		undef = 1;
		break;
	    }
	if (!null && !undef)
	    switch (sscanf(word1, "%ld:%d:%d:%d", &cat1, &r1, &g1, &b1)) {
	    case 2:
		b1 = g1 = r1;
		break;
	    case 4:
		break;
	    default:
		if (sscanf(word1, "%lf:%d:%d:%d", &val1, &r1, &g1, &b1) == 4)
		    fp_rule = 1;
		else if (sscanf(word1, "%lf:%d", &val1, &r1) == 2) {
		    fp_rule = 1;
		    b1 = g1 = r1;
		}
		else
		    continue;	/* other lines are ignored */
	    }
	if (n == 2) {
	    switch (sscanf(word2, "%ld:%d:%d:%d", &cat2, &r2, &g2, &b2)) {
	    case 2:
		b2 = g2 = r2;
		if (fp_rule)
		    val2 = (DCELL) cat2;
		break;
	    case 4:
		if (fp_rule)
		    val2 = (DCELL) cat2;
		break;
	    default:
		if (sscanf(word2, "%lf:%d:%d:%d", &val2, &r2, &g2, &b2) == 4) {
		    if (!fp_rule)
			val1 = (DCELL) cat1;
		    fp_rule = 1;
		}
		else if (sscanf(word2, "%lf:%d", &val2, &r2) == 2) {
		    if (!fp_rule)
			val1 = (DCELL) cat1;
		    fp_rule = 1;
		    b2 = g2 = r2;
		}
		else
		    continue;	/* other lines are ignored */
	    }
	}
	else {
	    if (!fp_rule)
		cat2 = cat1;
	    else
		val2 = val1;
	    r2 = r1;
	    g2 = g1;
	    b2 = b1;
	}
	if (null)
	    Rast_set_null_value_color(r1, g1, b1, colors);
	else if (undef)
	    Rast_set_default_color(r1, g1, b1, colors);

	else if (modular) {
	    if (fp_rule)
		Rast_add_modular_d_color_rule((DCELL *) & val1, r1, g1,
					      b1, (DCELL *) & val2, r2,
					      g2, b2, colors);
	    else
		Rast_add_modular_c_color_rule((CELL *) & cat1, r1, g1, b1,
					      (CELL *) & cat2, r2, g2, b2,
					      colors);
	}
	else {
	    if (fp_rule)
		Rast_add_d_color_rule((DCELL *) & val1, r1, g1, b1,
				      (DCELL *) & val2, r2, g2, b2, colors);
	    else
		Rast_add_c_color_rule((CELL *) & cat1, r1, g1, b1,
				      (CELL *) & cat2, r2, g2, b2, colors);
	}
	G_debug(3, "adding rule %ld=%.2lf %d %d %d  %ld=%.2lf %d %d %d",
		cat1, val1, r1, g1, b1, cat2, val2, r2, g2, b2);
    }
    return 1;
}

static int read_old_colors(FILE * fd, struct Colors *colors)
{
    char buf[256];
    long n;
    long min;
    float red_f, grn_f, blu_f;
    int red, grn, blu;
    int old;
    int zero;

    Rast_init_colors(colors);
    /*
     * first line in pre 3.0 color files is number of colors - ignore
     * otherwise it is #min first color, and the next line is for color 0
     */
    if (fgets(buf, sizeof buf, fd) == NULL)
	return -1;

    G_strip(buf);
    if (*buf == '#') {		/* 3.0 format */
	old = 0;
	if (sscanf(buf + 1, "%ld", &min) != 1)	/* first color */
	    return -1;
	zero = 1;
    }
    else {
	old = 1;
	min = 0;
	zero = 0;
    }

    colors->cmin = min;
    n = min;
    while (fgets(buf, sizeof buf, fd)) {
	if (old) {
	    if (sscanf(buf, "%f %f %f", &red_f, &grn_f, &blu_f) != 3)
		return -1;

	    red = 256 * red_f;
	    grn = 256 * grn_f;
	    blu = 256 * blu_f;
	}
	else {
	    switch (sscanf(buf, "%d %d %d", &red, &grn, &blu)) {
	    case 1:
		blu = grn = red;
		break;
	    case 2:
		blu = grn;
		break;
	    case 3:
		break;
	    default:
		return -1;
	    }
	}
	if (zero) {
	    Rast__insert_color_into_lookup((CELL) 0, red, grn, blu,
					   &colors->fixed);
	    zero = 0;
	}
	else
	    Rast__insert_color_into_lookup((CELL) n++, red, grn, blu,
					   &colors->fixed);
    }
    colors->cmax = n - 1;

    return 0;
}

/*!
 * \brief Mark colors as floating-point.
 *
 * Sets a flag in the <i>colors</i> structure that indicates that
 * these colors should only be looked up using floating-point raster
 * data (not integer data). In particular if this flag is set, the
 * routine Rast_get_c_colors_min_max() should return min=-255$^3$ and
 * max=255$^3$.
 *
 * \param colors pointer to Colors structure
 */
void Rast_mark_colors_as_fp(struct Colors *colors)
{
    colors->is_float = 1;
}