/* summarized distance centroid */
void label_position3(double *x, double *y) const
{
if (type_ == LineString || type_ == MultiLineString)
{
middle_point(x,y);
return;
}
unsigned i = 0;
double l = 0.0;
double tl = 0.0;
double cx = 0.0;
double cy = 0.0;
double x0 = 0.0;
double y0 = 0.0;
double x1 = 0.0;
double y1 = 0.0;
unsigned size = cont_.size();
for (i = 0; i < size-1; i++)
{
cont_.get_vertex(i,&x0,&y0);
cont_.get_vertex(i+1,&x1,&y1);
l = distance(x0,y0,x1,y1);
cx += l * (x1 + x0)/2;
cy += l * (y1 + y0)/2;
tl += l;
}
*x = cx / tl;
*y = cy / tl;
}
/* center of gravity centroid
- best visually but does not work with multipolygons
*/
void label_position(double *x, double *y) const
{
if (type_ == LineString || type_ == MultiLineString)
{
middle_point(x,y);
return;
}
unsigned size = cont_.size();
if (size < 3)
{
cont_.get_vertex(0,x,y);
return;
}
double ai;
double atmp = 0;
double xtmp = 0;
double ytmp = 0;
double x0 =0;
double y0 =0;
double x1 =0;
double y1 =0;
double ox =0;
double oy =0;
unsigned i;
// Use first point as origin to improve numerical accuracy
cont_.get_vertex(0,&ox,&oy);
for (i = 0; i < size-1; i++)
{
cont_.get_vertex(i,&x0,&y0);
cont_.get_vertex(i+1,&x1,&y1);
x0 -= ox; y0 -= oy;
x1 -= ox; y1 -= oy;
ai = x0 * y1 - x1 * y0;
atmp += ai;
xtmp += (x1 + x0) * ai;
ytmp += (y1 + y0) * ai;
}
if (atmp != 0)
{
*x = (xtmp/(3*atmp)) + ox;
*y = (ytmp/(3*atmp)) + oy;
return;
}
*x=x0;
*y=y0;
}
bool hit_test(value_type x, value_type y, double tol) const
{
if (cont_.size() == 1) {
// Handle points
double x0, y0;
cont_.get_vertex(0, &x0, &y0);
return distance(x, y, x0, y0) <= fabs(tol);
} else if (cont_.size() > 1) {
bool inside=false;
double x0=0;
double y0=0;
rewind(0);
vertex(&x0, &y0);
unsigned command;
double x1,y1;
while (SEG_END != (command=vertex(&x1, &y1)))
{
if (command == SEG_MOVETO)
{
x0 = x1;
y0 = y1;
continue;
}
if ((((y1 <= y) && (y < y0)) ||
((y0 <= y) && (y < y1))) &&
( x < (x0 - x1) * (y - y1)/ (y0 - y1) + x1))
inside=!inside;
x0=x1;
y0=y1;
}
return inside;
}
return false;
}
void middle_point(double *x, double *y) const
{
// calculate mid point on path
double x0=0;
double y0=0;
double x1=0;
double y1=0;
unsigned size = cont_.size();
if (size == 1)
{
cont_.get_vertex(0,x,y);
}
else if (size == 2)
{
cont_.get_vertex(0,&x0,&y0);
cont_.get_vertex(1,&x1,&y1);
*x = 0.5 * (x1 + x0);
*y = 0.5 * (y1 + y0);
}
else
{
double len=0.0;
for (unsigned pos = 1; pos < size; ++pos)
{
cont_.get_vertex(pos-1,&x0,&y0);
cont_.get_vertex(pos,&x1,&y1);
double dx = x1 - x0;
double dy = y1 - y0;
len += std::sqrt(dx * dx + dy * dy);
}
double midlen = 0.5 * len;
double dist = 0.0;
for (unsigned pos = 1; pos < size;++pos)
{
cont_.get_vertex(pos-1,&x0,&y0);
cont_.get_vertex(pos,&x1,&y1);
double dx = x1 - x0;
double dy = y1 - y0;
double seg_len = std::sqrt(dx * dx + dy * dy);
if (( dist + seg_len) >= midlen)
{
double r = (midlen - dist)/seg_len;
*x = x0 + (x1 - x0) * r;
*y = y0 + (y1 - y0) * r;
break;
}
dist += seg_len;
}
}
}
unsigned get_vertex(unsigned pos, double* x, double* y) const
{
return cont_.get_vertex(pos, x, y);
}
unsigned vertex(double* x, double* y) const
{
return cont_.get_vertex(itr_++,x,y);
}
unsigned vertex(std::size_t index, double* x, double* y) const
{
return cont_.get_vertex(index, x, y);
}
