LinearLocation LengthLocationMap::getLocationForward(double length) const
{
if (length <= 0.0)
return LinearLocation();
double totalLength = 0.0;
LinearIterator it (linearGeom);
while (it.hasNext())
{
if (! it.isEndOfLine())
{
Coordinate p0 = it.getSegmentStart();
Coordinate p1 = it.getSegmentEnd();
double segLen = p1.distance(p0);
// length falls in this segment
if (totalLength + segLen > length)
{
double frac = (length - totalLength) / segLen;
unsigned int compIndex = it.getComponentIndex();
unsigned int segIndex = it.getVertexIndex();
return LinearLocation(compIndex, segIndex, frac);
}
totalLength += segLen;
}
it.next();
}
// length is longer than line - return end location
return LinearLocation::getEndLocation(linearGeom);
}
/* private */
LinearLocation
LengthLocationMap::getLocationForward(double length) const
{
if (length <= 0.0)
return LinearLocation();
double totalLength = 0.0;
LinearIterator it (linearGeom);
while (it.hasNext())
{
/**
* Special handling is required for the situation when the
* length references exactly to a component endpoint.
* In this case, the endpoint location of the current component
* is returned,
* rather than the startpoint location of the next component.
* This produces consistent behaviour with the project method.
*/
if (it.isEndOfLine()) {
if (totalLength == length) {
unsigned int compIndex = it.getComponentIndex();
unsigned int segIndex = it.getVertexIndex();
return LinearLocation(compIndex, segIndex, 0.0);
}
}
else {
Coordinate p0 = it.getSegmentStart();
Coordinate p1 = it.getSegmentEnd();
double segLen = p1.distance(p0);
// length falls in this segment
if (totalLength + segLen > length)
{
double frac = (length - totalLength) / segLen;
unsigned int compIndex = it.getComponentIndex();
unsigned int segIndex = it.getVertexIndex();
return LinearLocation(compIndex, segIndex, frac);
}
totalLength += segLen;
}
it.next();
}
// length is longer than line - return end location
return LinearLocation::getEndLocation(linearGeom);
}
/* private */
LinearLocation
LengthLocationMap::resolveHigher(const LinearLocation& loc) const
{
if (! loc.isEndpoint(*linearGeom)) return loc;
unsigned int compIndex = loc.getComponentIndex();
// if last component can't resolve any higher
if (compIndex >= linearGeom->getNumGeometries() - 1) return loc;
do {
compIndex++;
} while (compIndex < linearGeom->getNumGeometries() - 1
&& linearGeom->getGeometryN(compIndex)->getLength() == 0);
// resolve to next higher location
return LinearLocation(compIndex, 0, 0.0);
}
