Geografic-Information-System/display/d.vect/label.c

#include <grass/gis.h>
#include <grass/vector.h>
#include <grass/display.h>
#include <grass/glocale.h>
#include "local_proto.h"
#include "plot.h"

static int process_line(int, const struct line_pnts *,
			const struct line_cats *, LATTR *,
			int, const struct cat_list *);

int display_label(struct Map_info *Map, int type,
		  struct cat_list *Clist, LATTR *lattr, int chcat)
{
    int ltype;
    struct line_pnts *Points;
    struct line_cats *Cats;
    int ogr_centroids;

    const struct Format_info *finfo;
    
    Points = Vect_new_line_struct();
    Cats = Vect_new_cats_struct();

    Vect_rewind(Map);

    ogr_centroids = FALSE;
    finfo = Vect_get_finfo(Map);
    if (Vect_maptype(Map) == GV_FORMAT_OGR ||
	(Vect_maptype(Map) == GV_FORMAT_POSTGIS &&
         finfo->pg.toposchema_name == NULL)) {
	if (Vect_level(Map) < 2)
	    G_warning(_("Topology level required for drawing centroids "
			"for OGR layers"));
	else if (Vect_get_num_primitives(Map, GV_CENTROID) > 0 &&
		 type & GV_CENTROID)
	    /* label centroids from topo, don't label boundaries */
	    ogr_centroids = TRUE;
    }
    
    while (TRUE) {
	ltype = Vect_read_next_line(Map, Points, Cats);
	if (ltype == -1)
	    G_fatal_error(_("Unable to read vector map"));
	else if (ltype == -2) /* EOF */
	    break;
	
        if (!(type & ltype) && !((type & GV_AREA) && (ltype & GV_CENTROID)))
	    continue;		/* used for both lines and labels */
	
	if (ogr_centroids && ltype == GV_BOUNDARY)
	    /* do not label boundaries */
	    continue;

	process_line(ltype, Points, Cats, lattr, chcat, Clist);
    }

    if (ogr_centroids) {
	/* show label for centroids stored in topo (for OGR layers
	   only) */
	int line, nlines;
	struct bound_box box;
	struct boxlist *list;
	
	list = Vect_new_boxlist(FALSE); /* bboxes not needed */
	Vect_get_constraint_box(Map, &box);
	nlines = Vect_select_lines_by_box(Map, &box, GV_CENTROID, list);
	G_debug(3, "ncentroids (ogr) = %d", nlines);
	
	for (line = 0; line < nlines; line++) {
	    ltype = Vect_read_line(Map, Points, Cats, list->id[line]);
	    process_line(ltype, Points, Cats, lattr, chcat, Clist);
	}
	Vect_destroy_boxlist(list);
    }

    Vect_destroy_line_struct(Points);
    Vect_destroy_cats_struct(Cats);

    return 0;
}

int process_line(int ltype, const struct line_pnts *Points,
		 const struct line_cats *Cats, LATTR *lattr,
		 int chcat, const struct cat_list *Clist)
{
    int i, cat, len;
    char *text = NULL, buf[100];
    
    D_RGB_color(lattr->color.R, lattr->color.G, lattr->color.B);
    D_text_size(lattr->size, lattr->size);
    if (lattr->font)
	D_font(lattr->font);
    if (lattr->enc)
	D_encoding(lattr->enc);
    
    if (chcat) {
	int found = 0;
	
	for (i = 0; i < Cats->n_cats; i++) {
	    if (Cats->field[i] == Clist->field &&
		Vect_cat_in_cat_list(Cats->cat[i], Clist)) {
		found = 1;
		break;
	    }
	}
	if (!found)
	    return 0;
    }
    else if (Clist->field > 0) {
	int found = 0;
	
	for (i = 0; i < Cats->n_cats; i++) {
	    if (Cats->field[i] == Clist->field) {
		found = 1;
		break;
	    }
	}
	/* lines with no category will be displayed */
	if (Cats->n_cats > 0 && !found)
	    return 0;
    }
    
    if (Vect_cat_get(Cats, lattr->field, &cat)) {
	for (i = 0; i < Cats->n_cats; i++) {
	    G_debug(3, "cat lab: field = %d, cat = %d", Cats->field[i],
		    Cats->cat[i]);
	    if (Cats->field[i] == lattr->field) {	/* all cats of given lfield */
		if (!text) {
		    sprintf(buf, "%d", Cats->cat[i]);
		    text = G_calloc(strlen(buf), sizeof(char));
		    text[0] = '\0';
		    strcpy(text, buf);
		}
		else {
		    sprintf(buf, "/%d", Cats->cat[i]);
		    len = strlen(text) + strlen(buf) + 1;
		    text = G_realloc(text, len * sizeof(char));
		    strcat(text, buf);
		}
	    }
	}
	show_label_line(Points, ltype, lattr, text);
    }
    
    if (text)
	G_free(text);

    return 1;
}

void show_label(double *px, double *py, LATTR *lattr, const char *text)
{
    double X = *px, Y = *py;
    int Xoffset, Yoffset;
    double xarr[5], yarr[5];
    double T, B, L, R;

    X = X + D_get_d_to_u_xconv() * 0.5 * lattr->size;
    Y = Y + D_get_d_to_u_yconv() * 1.5 * lattr->size;

    D_pos_abs(X, Y);
    D_get_text_box(text, &T, &B, &L, &R);

    /* Expand border 1/2 of text size */
    T = T - D_get_d_to_u_yconv() * lattr->size / 2;
    B = B + D_get_d_to_u_yconv() * lattr->size / 2;
    L = L - D_get_d_to_u_xconv() * lattr->size / 2;
    R = R + D_get_d_to_u_xconv() * lattr->size / 2;

    Xoffset = 0;
    Yoffset = 0;
    if (lattr->xref == LCENTER)
	Xoffset = -(R - L) / 2;
    if (lattr->xref == LRIGHT)
	Xoffset = -(R - L);
    if (lattr->yref == LCENTER)
	Yoffset = -(B - T) / 2;
    if (lattr->yref == LBOTTOM)
	Yoffset = -(B - T);

    if (lattr->has_bgcolor || lattr->has_bcolor) {
	xarr[0] = xarr[1] = xarr[4] = L + Xoffset;
	xarr[2] = xarr[3] = R + Xoffset;
	yarr[0] = yarr[3] = yarr[4] = B + Yoffset;
	yarr[1] = yarr[2] = T + Yoffset;

	if (lattr->has_bgcolor) {
	    D_RGB_color(lattr->bgcolor.R, lattr->bgcolor.G,
			lattr->bgcolor.B);
	    D_polygon_abs(xarr, yarr, 5);
	}

	if (lattr->has_bcolor) {
	    D_RGB_color(lattr->bcolor.R, lattr->bcolor.G,
			lattr->bcolor.B);
	    D_polyline_abs(xarr, yarr, 5);
	}
	D_RGB_color(lattr->color.R, lattr->color.G, lattr->color.B);
    }

    D_pos_abs(X + Xoffset, Y + Yoffset);
    D_text(text);
}

void show_label_line(const struct line_pnts *Points, int ltype, LATTR *lattr,
		     const char *text)
{
    double X, Y;

    if ((ltype & GV_POINTS) || Points->n_points == 1)
	/* point/centroid or line/boundary with one coor */
    {
	X = Points->x[0];
	Y = Points->y[0];
    }
    else if (Points->n_points == 2) {	/* line with two coors */
	X = (Points->x[0] + Points->x[1]) / 2;
	Y = (Points->y[0] + Points->y[1]) / 2;
    }
    else {
	int i = Points->n_points / 2;
	X = Points->x[i];
	Y = Points->y[i];
    }

    show_label(&X, &Y, lattr, text);
}