Geografic-Information-System/lib/gis/color_rule.c

/**
 * \file color_rule.c
 *
 * \brief GIS Library - Color rules.
 *
 * (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 GRASS GIS Development Team
 *
 * \date 1999-2008
 */

#include <grass/gis.h>

#define LIMIT(x) if (x < 0) x = 0; else if (x > 255) x = 255;

static void add_color_rule(const void *, int, int, int,
			   const void *, int, int, int,
			   struct _Color_Info_ *, int,
			   DCELL *, DCELL *, RASTER_MAP_TYPE);


/*!
 * \brief Adds the floating-point rule (DCELL version)
 *
 * See G_add_raster_color_rule() for details.
 *
 *  \param v1 cell value
 *  \param r1,g1,b1 color value
 *  \param v2 cell value
 *  \param r2,g2,b2 color value
 *  \param[in,out] colors pointer to color table structure
 *  \return
 */

void G_add_d_raster_color_rule(
    const DCELL * val1, int r1, int g1, int b1,
    const DCELL * val2, int r2, int g2, int b2,
    struct Colors *colors)
{
    add_color_rule(val1, r1, g1, b1, val2, r2, g2, b2, &colors->fixed,
		   colors->version, &colors->cmin, &colors->cmax, DCELL_TYPE);
}


/*!
 * \brief Adds the floating-point rule (FCELL version)
 *
 * See G_add_raster_color_rule() for details.
 *
 *  \param v1 cell value
 *  \param r1,g1,b1 color value
 *  \param v2 cell value
 *  \param r2,g2,b2 color value
 *  \param[in,out] colors pointer to color table structure
 *  \return
 */

void G_add_f_raster_color_rule(
    const FCELL * cat1, int r1, int g1, int b1,
    const FCELL * cat2, int r2, int g2, int b2,
    struct Colors *colors)
{
    add_color_rule(cat1, r1, g1, b1, cat2, r2, g2, b2, &colors->fixed,
		   colors->version, &colors->cmin, &colors->cmax, FCELL_TYPE);
}


/*!
 * \brief Adds the floating-point rule (CCELL version)
 *
 * See G_add_raster_color_rule() for details.
 *
 *  \param v1 cell value
 *  \param r1,g1,b1 color value
 *  \param v2 cell value
 *  \param r2,g2,b2 color value
 *  \param[in,out] colors pointer to color table structure
 *  \return
 */

void G_add_c_raster_color_rule(
    const CELL * cat1, int r1, int g1, int b1,
    const CELL * cat2, int r2, int g2, int b2,
    struct Colors *colors)
{
    add_color_rule(cat1, r1, g1, b1, cat2, r2, g2, b2, &colors->fixed,
		   colors->version, &colors->cmin, &colors->cmax, CELL_TYPE);
}


/*!
 * \brief Adds the floating-point rule
 *
 * Adds the floating-point rule that the range [<em>v1,v2</em>] gets a
 * linear ramp of colors from [<em>r1,g1,b1</em>] to
 * [<em>r2,g2,b2</em>].
 * If either <em>v1</em> or <em>v2</em> is the NULL-value, this call is converted into
 * <tt>G_set_null_value_color (r1, g1, b1, colors)</tt>
 *
 *  - If <em>map_type</em> is CELL_TYPE, calls G_add_c_raster_color_rule()
 *  - If <em>map_type</em> is FCELL_TYPE, calls G_add_f_raster_color_rule()
 *  - If <em>map_type</em> is DCELL_TYPE, calls G_add_d_raster_color_rule()
 *
 *  \param v1 cell value
 *  \param r1,g1,b1 color value
 *  \param v2 cell value
 *  \param r2,g2,b2 color value
 *  \param[in,out] colors pointer to color table structure
 *  \param data_type raster data type (CELL, FCELL, DCELL)
 *  \return
 */

void G_add_raster_color_rule(
    const void *val1, int r1, int g1, int b1,
    const void *val2, int r2, int g2, int b2,
    struct Colors *colors, RASTER_MAP_TYPE data_type)
{
    add_color_rule(val1, r1, g1, b1, val2, r2, g2, b2, &colors->fixed,
		   colors->version, &colors->cmin, &colors->cmax, data_type);
}


/*!
 * \brief Set colors rules
 *
 * This is the heart
 * and soul of the new color logic. It adds a color rule to the <b>colors</b>
 * structure. The colors defined by the red, green, and blue values
 * <b>r1,g1,b1</b> and <b>r2,g2,b2</b> are assigned to <b>cat1</b> and
 * <b>cat2</b> respectively. Colors for data values between <b>cat1</b> and
 * <b>cat2</b> are not stored in the structure but are interpolated when
 * queried by <i>G_lookup_colors</i> and<i>G_get_color.</i> The color
 * components <b>r1,g1,b1</b> and <b>r2,g2,b2</b> must be in the range
 * 0 -- 255.
 * For example, to create a linear grey scale for the range 200 -- 1000:
 \code
 struct Colors colr;
 G_init_colors (&colr);
 G_add_color_rule ((CELL)200, 0,0,0, (CELL)1000, 255,255,255);
 \endcode
 * The programmer is encouraged to review Raster_Color_Table_Format how
 * this routine fits into the 5.x raster color logic.
 * <b>Note.</b> The <b>colors</b> structure must have been initialized by
 * <i>G_init_colors.</i> See Predefined_Color_Tables for routines to
 * build some predefined color tables. 
 *
 *  \param cat1 cell value
 *  \param r1,g1,b1 color value
 *  \param cat2 cell value
 *  \param r2,g2,b2 color value
 *  \param[in,out] colors pointer to color table structure
 *  \return
 */

void G_add_color_rule(
    CELL cat1, int r1, int g1, int b1,
    CELL cat2, int r2, int g2,
    int b2, struct Colors *colors)
{
    add_color_rule((void *)&cat1, r1, g1, b1, (void *)&cat2, r2, g2, b2,
		   &colors->fixed, colors->version, &colors->cmin,
		   &colors->cmax, CELL_TYPE);
}

/**
 * \brief Add modular color rule (DCELL version)
 *
 * \param val1 cell value
 * \param r1,g1,b1 color value
 * \param val2 cell value
 * \param r2,g2,b2 color value
 * \param[in,out] colors pointer to color table structure
 *
 * \return -1 on failure
 * \return 1 on success
 */
int G_add_modular_d_raster_color_rule(
    const DCELL * val1, int r1, int g1, int b1,
    const DCELL * val2, int r2, int g2, int b2,
    struct Colors *colors)
{
    DCELL min, max;

    if (colors->version < 0)
	return -1;		/* can't use this on 3.0 colors */
    min = colors->cmin;
    max = colors->cmax;
    add_color_rule(val1, r1, g1, b1, val2, r2, g2, b2, &colors->modular, 0,
		   &colors->cmin, &colors->cmax, DCELL_TYPE);
    colors->cmin = min;		/* don't reset these */
    colors->cmax = max;

    return 1;
}

/**
 * \brief Add modular color rule (FCELL version)
 *
 * \param val1 cell value
 * \param r1,g1,b1 color value
 * \param val2 cell value
 * \param r2,g2,b2 color value
 * \param[in,out] colors pointer to color table structure
 *
 * \return -1 on failure
 * \return 1 on success
 */
int G_add_modular_f_raster_color_rule(
    const FCELL * val1, int r1, int g1, int b1,
    const FCELL * val2, int r2, int g2, int b2,
    struct Colors *colors)
{
    DCELL min, max;

    if (colors->version < 0)
	return -1;		/* can;t use this on 3.0 colors */
    min = colors->cmin;
    max = colors->cmax;
    add_color_rule(val1, r1, g1, b1, val2, r2, g2, b2, &colors->modular, 0,
		   &colors->cmin, &colors->cmax, FCELL_TYPE);
    colors->cmin = min;		/* don't reset these */
    colors->cmax = max;

    return 1;
}

/**
 * \brief Add modular color rule (CCELL version)
 *
 * \param val1 cell value
 * \param r1,g1,b1 color value
 * \param val2 cell value
 * \param r2,g2,b2 color value
 * \param[in,out] colors pointer to color table structure
 *
 * \return -1 on failure
 * \return 1 on success
 */
int G_add_modular_c_raster_color_rule(
    const CELL * val1, int r1, int g1, int b1,
    const CELL * val2, int r2, int g2, int b2,
    struct Colors *colors)
{
    return G_add_modular_color_rule(*val1, r1, g1, b1, *val2, r2, g2, b2,
				    colors);
}

/**
 * \brief Add modular color rule
 *
 * Question: shouldn't this function call
 * G_add_modular_<data_type>_raster_color_rule() instead???
 *
 * \param val1 cell value
 * \param r1,g1,b1 color value
 * \param val2 cell value
 * \param r2,g2,b2 color value
 * \param[in,out] colors pointer to color table structure
 * \param data_type raster data type
 *
 * \return -1 on failure
 * \return 1 on success
 */
int G_add_modular_raster_color_rule(
    const void *val1, int r1, int g1, int b1,
    const void *val2, int r2, int g2, int b2,
    struct Colors *colors, RASTER_MAP_TYPE data_type)
{
    CELL min, max;

    if (colors->version < 0)
	return -1;		/* can't use this on 3.0 colors */
    min = colors->cmin;
    max = colors->cmax;
    add_color_rule(val1, r1, g1, b1, val2, r2, g2, b2, &colors->modular, 0,
		   &colors->cmin, &colors->cmax, data_type);
    colors->cmin = min;		/* don't reset these */
    colors->cmax = max;

    return 1;
}

/**
 * \brief Add modular color rule
 *
 * This function seems to be same as
 * G_add_modular_raster_color_rule(). Can be removed?
 *
 * \param val1 cell value
 * \param r1,g1,b1 color value
 * \param val2 cell value
 * \param r2,g2,b2 color value
 * \param[in,out] colors pointer to color table structure
 * \param data_type raster data type
 *
 * \return -1 on failure
 * \return 1 on success
 */
int G_add_modular_color_rule(
    CELL cat1, int r1, int g1,
    int b1, CELL cat2, int r2,
    int g2, int b2, struct Colors *colors)
{
    CELL min, max;

    if (colors->version < 0)
	return -1;		/* can;t use this on 3.0 colors */
    min = colors->cmin;
    max = colors->cmax;
    add_color_rule((void *)&cat1, r1, g1, b1, (void *)&cat2, r2, g2, b2,
		   &colors->modular, 0, &colors->cmin, &colors->cmax,
		   CELL_TYPE);
    colors->cmin = min;		/* don't reset these */
    colors->cmax = max;

    return 1;
}

static void add_color_rule(const void *pt1, int r1, int g1, int b1,
			   const void *pt2, int r2, int g2, int b2,
			   struct _Color_Info_ *cp, int version, DCELL * cmin,
			   DCELL * cmax, RASTER_MAP_TYPE data_type)
{
    struct _Color_Rule_ *rule, *next;
    unsigned char red, grn, blu;
    DCELL min, max, val1, val2;
    CELL cat;

    val1 = G_get_raster_value_d(pt1, data_type);
    val2 = G_get_raster_value_d(pt2, data_type);
    /* allocate a low:high rule */
    rule = (struct _Color_Rule_ *)G_malloc(sizeof(*rule));
    rule->next = rule->prev = NULL;

    /* make sure colors are in the range [0,255] */
    LIMIT(r1);
    LIMIT(g1);
    LIMIT(b1);
    LIMIT(r2);
    LIMIT(g2);
    LIMIT(b2);

    /* val1==val2, use average color */
    /* otherwise make sure low < high */
    if (val1 == val2) {
	rule->low.value = rule->high.value = val1;
	rule->low.red = rule->high.red = (r1 + r2) / 2;
	rule->low.grn = rule->high.grn = (g1 + g2) / 2;
	rule->low.blu = rule->high.blu = (b1 + b2) / 2;
    }
    else if (val1 < val2) {
	rule->low.value = val1;
	rule->low.red = r1;
	rule->low.grn = g1;
	rule->low.blu = b1;

	rule->high.value = val2;
	rule->high.red = r2;
	rule->high.grn = g2;
	rule->high.blu = b2;
    }
    else {
	rule->low.value = val2;
	rule->low.red = r2;
	rule->low.grn = g2;
	rule->low.blu = b2;

	rule->high.value = val1;
	rule->high.red = r1;
	rule->high.grn = g1;
	rule->high.blu = b1;
    }

    /* keep track of the overall min and max, excluding null */
    if (G_is_d_null_value(&(rule->low.value)))
	return;
    if (G_is_d_null_value(&(rule->high.value)))
	return;
    min = rule->low.value;
    max = rule->high.value;
    if (min <= max) {
	if (cp->min > cp->max) {
	    cp->min = min;
	    cp->max = max;
	}
	else {
	    if (cp->min > min)
		cp->min = min;
	    if (cp->max < max)
		cp->max = max;
	}
    }
    if (*cmin > *cmax) {
	*cmin = cp->min;
	*cmax = cp->max;
    }
    else {
	if (*cmin > cp->min)
	    *cmin = cp->min;
	if (*cmax < cp->max)
	    *cmax = cp->max;
    }

    /* If version is old style (i.e., pre 4.0),
     *     interpolate this rule from min to max
     *     and insert each cat into the lookup table.
     *     Then free the rule.
     * Otherwise, free the lookup table, if active.
     *     G_organize_colors() will regenerate it
     *     Link this rule into the list of rules
     */

    if (version < 0) {
	for (cat = (CELL) min; cat <= (CELL) max; cat++) {
	    G__interpolate_color_rule((DCELL) cat, &red, &grn, &blu, rule);
	    G__insert_color_into_lookup(cat, (int)red, (int)grn, (int)blu,
					cp);
	}
	G_free(rule);
    }
    else {
	if (cp->rules)
	    cp->rules->prev = rule;
	rule->next = cp->rules;
	cp->rules = rule;

	/* prune the rules:
	 * remove all rules that are contained by this rule 
	 */
	min = rule->low.value;	/* mod 4.1 */
	max = rule->high.value;	/* mod 4.1 */
	cp->n_rules++;
	for (rule = rule->next; rule; rule = next) {
	    next = rule->next;	/* has to be done here, not in for stmt */
	    if (min <= rule->low.value && max >= rule->high.value) {
		if ((rule->prev->next = next))	/* remove from the list */
		    next->prev = rule->prev;
		G_free(rule);
		cp->n_rules--;
	    }
	}

	/* free lookup array, if allocated */
	G__color_free_lookup(cp);
	G__color_free_fp_lookup(cp);
    }
}