graph_label *add_label(v5d_info *info, gchar *str, v5d_graph_type gtype)
{
graph_label *label;
gint cnt=1, x, y;
if(info->graph_label_list){
cnt = g_list_length (info->graph_label_list )+1;
}
label_position(info->v5d_display_context, cnt, &x, &y);
label = (graph_label *) g_malloc(sizeof(graph_label));
label->gtype = gtype;
label->data = NULL;
label->labelid = vis5d_make_label(info->v5d_display_context, x,
y, chomp(str));
info->graph_label_list = g_list_append(info->graph_label_list, (gpointer) label);
return label;
}
void update_label(v5d_info *info, graph_label *label, gchar *str)
{
gint cnt, x, y;
vis5d_delete_label(info->v5d_display_context, label->labelid);
cnt = g_list_index(info->graph_label_list, label) + 1;
label_position(info->v5d_display_context, cnt, &x, &y);
label->labelid = vis5d_make_label(info->v5d_display_context, x,
y, chomp(str));
}
void update_graph_labels(v5d_info *info)
{
GList *item;
gint cnt=1, x, y;
if(! info->graph_label_list)
return;
item = g_list_first(info->graph_label_list);
while(item!=NULL){
label_position(info->v5d_display_context, cnt, &x, &y);
vis5d_move_label(info->v5d_display_context, ((graph_label *)item->data)->labelid,
x,y);
item = g_list_next(item);
cnt++;
}
}
void label_interior_position(double *x, double *y) const
{
// start with the default label position
label_position(x,y);
unsigned size = cont_.size();
// if we are not a polygon, or the default is within the polygon we are done
if (size < 3 || hit_test(*x,*y,0))
return;
// otherwise we find a horizontal line across the polygon and then return the
// center of the widest intersection between the polygon and the line.
std::vector<double> intersections; // only need to store the X as we know the y
double x0=0;
double y0=0;
rewind(0);
unsigned command = vertex(&x0, &y0);
double x1,y1;
while (SEG_END != (command=vertex(&x1, &y1)))
{
if (command != SEG_MOVETO)
{
// if the segments overlap
if (y0==y1)
{
if (y0==*y)
{
double xi = (x0+x1)/2.0;
intersections.push_back(xi);
}
}
// if the path segment crosses the bisector
else if ((y0 <= *y && y1 >= *y) ||
(y0 >= *y && y1 <= *y))
{
// then calculate the intersection
double xi = x0;
if (x0 != x1)
{
double m = (y1-y0)/(x1-x0);
double c = y0 - m*x0;
xi = (*y-c)/m;
}
intersections.push_back(xi);
}
}
x0 = x1;
y0 = y1;
}
// no intersections we just return the default
if (intersections.empty())
return;
x0=intersections[0];
double max_width = 0;
for (unsigned ii = 1; ii < intersections.size(); ++ii)
{
double x1=intersections[ii];
double xc=(x0+x1)/2.0;
double width = fabs(x1-x0);
if (width > max_width && hit_test(xc,*y,0))
{
*x=xc;
max_width = width;
}
}
}