C++ Vect_reset_line函数代码示例

/*!
  \brief Get area boundary points (native format)
  
  Used by Vect_build_line_area() and Vect_get_area_points().
  
  \param Map pointer to Map_info struct
  \param lines array of boundary lines
  \param n_lines number of lines in array
  \param[out] APoints pointer to output line_pnts struct

  \return number of points
  \return -1 on error
*/
int Vect__get_area_points_nat(const struct Map_info *Map, const plus_t *lines, int n_lines,
                              struct line_pnts *BPoints)
{
    int i, line, aline, dir;
    static struct line_pnts *Points;
    
    if (!Points)
        Points = Vect_new_line_struct();
    
    Vect_reset_line(BPoints);
    for (i = 0; i < n_lines; i++) {
        line = lines[i];
        aline = abs(line);
        G_debug(5, "  append line(%d) = %d", i, line);
        
        if (0 > Vect_read_line(Map, Points, NULL, aline))
            return -1;
        
        dir = line > 0 ? GV_FORWARD : GV_BACKWARD;
        Vect_append_points(BPoints, Points, dir);
        BPoints->n_points--;    /* skip last point, avoids duplicates */
    }
    BPoints->n_points++;        /* close polygon */

    return BPoints->n_points;
}

/*!
  \brief Get area boundary points (PostGIS Topology)
  
  Used by Vect_build_line_area() and Vect_get_area_points().

  \param Map pointer to Map_info struct
  \param lines array of boundary lines
  \param n_lines number of lines in array
  \param[out] APoints pointer to output line_pnts struct

  \return number of points
  \return -1 on error
*/
int Vect__get_area_points_pg(const struct Map_info *Map, const plus_t *lines, int n_lines,
                             struct line_pnts *APoints)
{
    int i, direction;
    
    struct Format_info_pg *pg_info;
    
    PGresult *res;
    
    pg_info = (struct Format_info_pg *)&(Map->fInfo.pg);
   
    Vect_reset_line(APoints);

    res = build_stmt(&(Map->plus), pg_info, lines, n_lines);
    if (!res)
        return -1;
    
    for (i = 0; i < n_lines; i++) {
        Vect__cache_feature_pg(PQgetvalue(res, i, 0), FALSE, FALSE,
                               &(pg_info->cache), NULL); /* do caching in readable way */
	direction = lines[i] > 0 ? GV_FORWARD : GV_BACKWARD;
	Vect_append_points(APoints, pg_info->cache.lines[0], direction);
	APoints->n_points--;	/* skip last point, avoids duplicates */
    }
    APoints->n_points++;	/* close polygon */

    PQclear(res);
    
    return APoints->n_points;
}

/*!
   \brief Returns polygon array of points for given isle

   \param Map pointer to Map_info structure
   \param isle island id
   \param[out] BPoints points array

   \return number of points
   \return -1 on error
 */
int Vect_get_isle_points(const struct Map_info *Map,
                         int isle, struct line_pnts *BPoints)
{
    const struct Plus_head *Plus;
    struct P_isle *Isle;

    G_debug(3, "Vect_get_isle_points(): isle = %d", isle);
    Vect_reset_line(BPoints);

    Plus = &(Map->plus);
    Isle = Plus->Isle[isle];
    
    if (Isle == NULL) {		/* dead isle */
	G_warning(_("Attempt to read points of nonexistent isle"));
	return -1;		/* error, because we should not read dead isles */
    }

    G_debug(3, "  n_lines = %d", Isle->n_lines);

    if (Map->format == GV_FORMAT_POSTGIS &&
        Map->fInfo.pg.toposchema_name &&
        Map->fInfo.pg.cache.ctype != CACHE_MAP) {
#ifdef HAVE_POSTGRES
        /* PostGIS Topology */
        return Vect__get_area_points_pg(Map, Isle->lines, Isle->n_lines, BPoints);
#else
        G_fatal_error(_("GRASS is not compiled with PostgreSQL support"));
#endif
    }
    /* native format */
    return Vect__get_area_points_nat(Map, Isle->lines, Isle->n_lines, BPoints);
}

void write_point(struct Map_info *Out, double x, double y, double z,
		 int line_cat, double along, int table)
{
    char buf[2000];

    G_debug(3, "write_point()");

    Vect_reset_line(PPoints);
    Vect_reset_cats(PCats);

    /* Write point */
    Vect_append_point(PPoints, x, y, z);
    Vect_cat_set(PCats, 1, line_cat);
    Vect_cat_set(PCats, 2, point_cat);
    Vect_write_line(Out, GV_POINT, PPoints, PCats);

    /* Attributes */
    if (!table) {
	db_zero_string(&stmt);
	sprintf(buf, "insert into %s values ( %d, %d, %.15g )", Fi->table,
		point_cat, line_cat, along);
	db_append_string(&stmt, buf);

	if (db_execute_immediate(driver, &stmt) != DB_OK) {
	    G_warning(_("Unable to insert new record: '%s'"),
		      db_get_string(&stmt));
	}
    }
    point_cat++;
}

void writePolyline( struct Map_info* map, int type, QgsPolyline polyline, struct line_cats *cats )
{
  Vect_reset_line( line );
  foreach ( QgsPoint point, polyline )
  {
    Vect_append_point( line, point.x(), point.y(), 0 );
  }

static int ring2pts(const GEOSGeometry *geom, struct line_pnts *Points)
{
    int i, ncoords;
    double x, y, z;
    const GEOSCoordSequence *seq = NULL;

    G_debug(3, "ring2pts()");

    Vect_reset_line(Points);
    if (!geom) {
	G_warning(_("Invalid GEOS geometry!"));
	return 0;
    }
    z = 0.0;
    ncoords = GEOSGetNumCoordinates(geom);
    if (!ncoords) {
	G_warning(_("No coordinates in GEOS geometry (can be ok for negative distance)!"));
	return 0;
    }
    seq = GEOSGeom_getCoordSeq(geom);
    for (i = 0; i < ncoords; i++) {
	GEOSCoordSeq_getX(seq, i, &x);
	GEOSCoordSeq_getY(seq, i, &y);
	if (x != x || x > DBL_MAX || x < -DBL_MAX)
	    G_fatal_error(_("Invalid x coordinate %f"), x);
	if (y != y || y > DBL_MAX || y < -DBL_MAX)
	    G_fatal_error(_("Invalid y coordinate %f"), y);
	Vect_append_point(Points, x, y, z);
    }

    return 1;
}

/* Writes a site to file open on fptr. */
int G_site_put(struct Map_info *Map, const Site * s)
{
    static struct line_pnts *Points = NULL;
    static struct line_cats *Cats = NULL;

    if (Points == NULL)
	Points = Vect_new_line_struct();
    if (Cats == NULL)
	Cats = Vect_new_cats_struct();

    Vect_reset_line(Points);
    Vect_reset_cats(Cats);

    /* no 3D support so far: s->dim[0] */
    Vect_append_point(Points, s->east, s->north, 0.0);

    G_debug(4, "cattype = %d", s->cattype);

    if (s->cattype == FCELL_TYPE || s->cattype == DCELL_TYPE)
	G_fatal_error(_("Category must be integer"));

    if (s->cattype == CELL_TYPE)
	Vect_cat_set(Cats, 1, s->ccat);

    Vect_write_line(Map, GV_POINT, Points, Cats);

    return 0;
}

void QgsGrassEditAddVertex::mouseMove( QgsPoint & newPoint )
{
  if ( e->mSelectedLine > 0 )
  {
    Vect_reset_line( e->mPoints );
    if ( e->mAddVertexEnd )
    {
      Vect_append_point( e->mPoints, e->mEditPoints->x[e->mSelectedPart],
                         e->mEditPoints->y[e->mSelectedPart], 0.0 );
      Vect_append_point( e->mPoints, newPoint.x(), newPoint.y(), 0.0 );
    }
    else
    {
      Vect_append_point( e->mPoints, e->mEditPoints->x[e->mSelectedPart-1],
                         e->mEditPoints->y[e->mSelectedPart-1], 0.0 );
      Vect_append_point( e->mPoints, newPoint.x(), newPoint.y(), 0.0 );
      Vect_append_point( e->mPoints, e->mEditPoints->x[e->mSelectedPart],
                         e->mEditPoints->y[e->mSelectedPart], 0.0 );
    }
    for ( int i = 0; i < e->mPoints->n_points; i++ )
    {
      QgsDebugMsg( QString( "%1 %2" ).arg( e->mPoints->x[i] ).arg( e->mPoints->y[i] ) );
    }

    e->displayDynamic( e->mPoints );
  }
}

void writePolyline( struct Map_info* map, int type, const QgsPolyline& polyline, struct line_cats *cats )
{
  Vect_reset_line( line );
  Q_FOREACH ( const QgsPoint& point, polyline )
  {
    Vect_append_point( line, point.x(), point.y(), 0 );
  }

int
pie(double cx, double cy, int size, double *val, int ncols, COLOR * ocolor,
    COLOR * colors)
{
    int i, j, n;
    double a, end_ang, ang, tot_sum, sum, step, r;
    double x, y;
    struct line_pnts *Points;

    G_debug(4, "pie(): cx = %f cy = %f", cx, cy);

    Points = Vect_new_line_struct();

    /* Calc sum */
    tot_sum = 0;
    for (i = 0; i < ncols; i++)
	tot_sum += val[i];

    step = PI / 180;
    r = (D_d_to_u_col(2) - D_d_to_u_col(1)) * size / 2;	/* do it better */
    /* Draw polygon for each value */
    sum = 0;
    ang = 0;
    for (i = 0; i < ncols; i++) {
	sum += val[i];
	end_ang = 2 * PI * sum / tot_sum;
	Vect_reset_line(Points);

	if (val[0] != tot_sum)	/* all in one slice, don't draw line to center */
	    Vect_append_point(Points, cx, cy, 0);

	n = (int)ceil((end_ang - ang) / step);
	for (j = 0, a = ang; j <= n; j++, a += step) {
	    if (a > end_ang)
		a = end_ang;
	    x = cx + r * cos(a);
	    y = cy + r * sin(a);
	    Vect_append_point(Points, x, y, 0);
	}
	ang = end_ang;

	if (val[0] != tot_sum)
	    Vect_append_point(Points, cx, cy, 0);

	if (!colors[i].none) {
	    D_RGB_color(colors[i].r, colors[i].g, colors[i].b);
	    D_polygon_abs(Points->x, Points->y, Points->n_points);
	}

	D_RGB_color(ocolor->r, ocolor->g, ocolor->b);
	D_polyline_abs(Points->x, Points->y, Points->n_points);
    }

    Vect_destroy_line_struct(Points);

    return 0;
}

/*!
  \brief Read feature from OGR layer at given offset (level 1)
  
  This function implements random access on level 1.

  \param Map pointer to Map_info structure 
  \param[out] line_p container used to store line points within
  \param[out] line_c container used to store line categories within
  \param offset given offset 
  
  \return line type
  \return 0 dead line
  \return -2 no more features
  \return -1 out of memory
*/
int V1_read_line_ogr(struct Map_info *Map,
		     struct line_pnts *line_p, struct line_cats *line_c, off_t offset)
{
    long FID;
    int type;
    OGRGeometryH hGeom;

    G_debug(4, "V1_read_line_ogr() offset = %lu offset_num = %lu",
	    (long) offset, (long) Map->fInfo.ogr.offset_num);

    if (offset >= Map->fInfo.ogr.offset_num)
	return -2;
    
    if (line_p != NULL)
	Vect_reset_line(line_p);
    if (line_c != NULL)
	Vect_reset_cats(line_c);

    FID = Map->fInfo.ogr.offset[offset];
    G_debug(4, "  FID = %ld", FID);
    
    /* coordinates */
    if (line_p != NULL) {
	/* Read feature to cache if necessary */
	if (Map->fInfo.ogr.feature_cache_id != FID) {
	    G_debug(4, "Read feature (FID = %ld) to cache", FID);
	    if (Map->fInfo.ogr.feature_cache) {
		OGR_F_Destroy(Map->fInfo.ogr.feature_cache);
	    }
	    Map->fInfo.ogr.feature_cache =
		OGR_L_GetFeature(Map->fInfo.ogr.layer, FID);
	    if (Map->fInfo.ogr.feature_cache == NULL) {
		G_fatal_error(_("Unable to get feature geometry, FID %ld"),
			      FID);
	    }
	    Map->fInfo.ogr.feature_cache_id = FID;
	}
	
	hGeom = OGR_F_GetGeometryRef(Map->fInfo.ogr.feature_cache);
	if (hGeom == NULL) {
	    G_fatal_error(_("Unable to get feature geometry, FID %ld"),
			  FID);
	}
	
	type = read_line(Map, hGeom, offset + 1, line_p);
    }
    else {
	type = get_line_type(Map, FID);
    }

    /* category */
    if (line_c != NULL) {
	Vect_cat_set(line_c, 1, (int) FID);
    }

    return type;
}

/*!
   \brief Writes point

   Writes GV_POINT to Out at the position of the node in <em>In</em>.

   \param In pointer to Map_info structure (input vector map)
   \param[in,out] Out pointer to Map_info structure (output vector map)
   \param node node id
   \param Cats pointer to line_cats structures
 */
void NetA_add_point_on_node(struct Map_info *In, struct Map_info *Out,
			    int node, struct line_cats *Cats)
{
    static struct line_pnts *Points;
    double x, y, z;

    Points = Vect_new_line_struct();
    Vect_get_node_coor(In, node, &x, &y, &z);
    Vect_reset_line(Points);
    Vect_append_point(Points, x, y, z);
    Vect_write_line(Out, GV_POINT, Points, Cats);
    Vect_destroy_line_struct(Points);
}

/*!
  \brief Reads feature from OGR layer (topology level)
 
  This function implements random access on level 2.
  
  \param Map pointer to Map_info structure
  \param[out] line_p container used to store line points within
  \param[out] line_c container used to store line categories within
  \param line feature id
  
  \return feature type
  \return -2 no more features
  \return -1 out of memory
*/
int V2_read_line_ogr(struct Map_info *Map, struct line_pnts *line_p,
		     struct line_cats *line_c, int line)
{
    struct P_line *Line;
    G_debug(4, "V2_read_line_ogr() line = %d", line);
    
    Line = Map->plus.Line[line];
    
    if (Line == NULL)
	G_fatal_error(_("Attempt to read dead feature %d"), line);

    if (Line->type == GV_CENTROID) {
	G_debug(4, "Centroid");
	
	if (line_p != NULL) {
	    int i, found;
	    struct bound_box box;
	    struct boxlist list;
	    struct P_topo_c *topo = (struct P_topo_c *)Line->topo;
	    
	    /* get area bbox */
	    Vect_get_area_box(Map, topo->area, &box);
	    /* search in spatial index for centroid with area bbox */
	    dig_init_boxlist(&list, 1);
	    Vect_select_lines_by_box(Map, &box, Line->type, &list);
	    
	    found = 0;
	    for (i = 0; i < list.n_values; i++) {
		if (list.id[i] == line) {
		    found = i;
		    break;
		}
	    }

	    Vect_reset_line(line_p);
	    Vect_append_point(line_p, list.box[found].E, list.box[found].N, 0.0);
	}

	if (line_c != NULL) {
	  /* cat = FID and offset = FID for centroid */
	  Vect_reset_cats(line_c);
	  Vect_cat_set(line_c, 1, (int) Line->offset);
	}
	
	return GV_CENTROID;
    }
    
    return V1_read_line_ogr(Map, line_p, line_c, Line->offset);
}

/*!
  \brief Create line segment.
  
  Creates segment of InPoints from start to end measured along the
  line and write it to OutPoints.
  
  If the distance is greater than line length or negative, error is
  returned.
  
  \param InPoints input line
  \param start segment number
  \param end segment number
  \param OutPoints output line
  
  \return 1 success
  \return 0 error when start > length or end < 0 or start < 0 or end > length
*/
int Vect_line_segment(const struct line_pnts *InPoints, double start, double end,
		      struct line_pnts *OutPoints)
{
    int i, seg1, seg2;
    double length, tmp;
    double x1, y1, z1, x2, y2, z2;

    G_debug(3, "Vect_line_segment(): start = %f, end = %f, n_points = %d",
	    start, end, InPoints->n_points);

    Vect_reset_line(OutPoints);

    if (start > end) {
	tmp = start;
	start = end;
	end = tmp;
    }

    /* Check start/end */
    if (end < 0)
	return 0;
    length = Vect_line_length(InPoints);
    if (start > length)
	return 0;

    /* Find coordinates and segments of start/end */
    seg1 = Vect_point_on_line(InPoints, start, &x1, &y1, &z1, NULL, NULL);
    seg2 = Vect_point_on_line(InPoints, end, &x2, &y2, &z2, NULL, NULL);

    G_debug(3, "  -> seg1 = %d seg2 = %d", seg1, seg2);

    if (seg1 == 0 || seg2 == 0) {
	G_warning(_("Segment outside line, no segment created"));
	return 0;
    }

    Vect_append_point(OutPoints, x1, y1, z1);

    for (i = seg1; i < seg2; i++) {
	Vect_append_point(OutPoints, InPoints->x[i], InPoints->y[i],
			  InPoints->z[i]);
    };

    Vect_append_point(OutPoints, x2, y2, z2);
    Vect_line_prune(OutPoints);

    return 1;
}

void QgsGrassEditNewLine::activate()
{
  QgsDebugMsg( "entered." );

  // Display dynamic segment
  if ( e->mEditPoints->n_points > 0 )
  {
    Vect_reset_line( e->mPoints );
    Vect_append_points( e->mPoints, e->mEditPoints, GV_FORWARD );
    QgsPoint point = toMapCoordinates( e->mCanvas->mouseLastXY() );
    Vect_append_point( e->mPoints, point.x(), point.y(), 0.0 );
    e->displayDynamic( e->mPoints );
  }

  QgsGrassEditTool::activate(); // call default bahivour
}