template<> NValue NValue::callUnary<FUNC_VOLT_POLYGONFROMTEXT>() const
{
bool is_shell = true;
if (isNull()) {
return NValue::getNullValue(VALUE_TYPE_GEOGRAPHY);
}
int32_t textLength;
const char* textData = getObject_withoutNull(&textLength);
const std::string wkt(textData, textLength);
// Discard whitespace, but return commas or parentheses as tokens
Tokenizer tokens(wkt, boost::char_separator<char>(" \f\n\r\t\v", ",()"));
Tokenizer::iterator it = tokens.begin();
Tokenizer::iterator end = tokens.end();
if (! boost::iequals(*it, "polygon")) {
throwInvalidWktPoly("does not start with POLYGON keyword");
}
++it;
if (! boost::iequals(*it, "(")) {
throwInvalidWktPoly("missing left parenthesis after POLYGON keyword");
}
++it;
std::size_t length = Polygon::serializedLengthNoLoops();
std::vector<std::unique_ptr<S2Loop> > loops;
while (it != end) {
loops.push_back(std::unique_ptr<S2Loop>(new S2Loop()));
readLoop(is_shell, wkt, it, end, loops.back().get());
// Only the first loop is a shell.
is_shell = false;
length += Loop::serializedLength(loops.back()->num_vertices());
if (*it == ",") {
++it;
}
else if (*it == ")") {
++it;
break;
}
else {
throwInvalidWktPoly("unexpected token: '" + (*it) + "'");
}
}
if (it != end) {
// extra stuff after input
throwInvalidWktPoly("unrecognized input after WKT: '" + (*it) + "'");
}
NValue nval = ValueFactory::getUninitializedTempGeographyValue(length);
char* storage = const_cast<char*>(ValuePeeker::peekObjectValue(nval));
Polygon poly;
poly.init(&loops); // polygon takes ownership of loops here.
SimpleOutputSerializer output(storage, length);
poly.saveToBuffer(output);
return nval;
}
static NValue polygonFromText(const std::string &wkt, bool doValidation)
{
// Discard whitespace, but return commas or parentheses as tokens
Tokenizer tokens(wkt, boost::char_separator<char>(" \f\n\r\t\v", ",()"));
Tokenizer::iterator it = tokens.begin();
Tokenizer::iterator end = tokens.end();
if (! boost::iequals(*it, "polygon")) {
throwInvalidWktPoly("does not start with POLYGON keyword");
}
++it;
if (! boost::iequals(*it, "(")) {
throwInvalidWktPoly("missing left parenthesis after POLYGON keyword");
}
++it;
bool is_shell = true;
std::size_t length = Polygon::serializedLengthNoLoops();
std::vector<std::unique_ptr<S2Loop> > loops;
while (it != end) {
loops.push_back(std::unique_ptr<S2Loop>(new S2Loop()));
readLoop(is_shell, wkt, it, end, loops.back().get());
// Only the first loop is a shell.
is_shell = false;
length += Loop::serializedLength(loops.back()->num_vertices());
if (*it == ",") {
++it;
}
else if (*it == ")") {
++it;
break;
}
else {
throwInvalidWktPoly("unexpected token: '" + (*it) + "'");
}
}
if (it != end) {
// extra stuff after input
throwInvalidWktPoly("unrecognized input after WKT: '" + (*it) + "'");
}
NValue nval = ValueFactory::getUninitializedTempGeographyValue(length);
char* storage = const_cast<char*>(ValuePeeker::peekObjectValue(nval));
Polygon poly;
poly.init(&loops); // polygon takes ownership of loops here.
if (doValidation) {
std::stringstream validReason;
if (!poly.IsValid(&validReason)
|| isMultiPolygon(poly, &validReason)) {
throwInvalidWktPoly(validReason.str());
}
}
SimpleOutputSerializer output(storage, length);
poly.saveToBuffer(output);
return nval;
}
static GeographyPointValue::Coord stringToCoord(int pointOrPoly,
const std::string& input,
const std::string& val)
{
GeographyPointValue::Coord coord = 0.0;
try {
coord = boost::lexical_cast<GeographyPointValue::Coord>(val);
}
catch (const boost::bad_lexical_cast&) {
if (pointOrPoly == POLY) {
throwInvalidWktPoly("expected a number but found '" + val + "'");
}
else {
throwInvalidWktPoint(input);
}
}
return coord;
}
static void readLoop(bool is_shell,
const std::string &wkt,
Tokenizer::iterator &it,
const Tokenizer::iterator &end,
S2Loop *loop)
{
if (! boost::iequals(*it, "(")) {
throwInvalidWktPoly("expected left parenthesis to start a loop");
}
++it;
std::vector<S2Point> points;
while (it != end && *it != ")") {
GeographyPointValue::Coord lng = stringToCoord(POLY, wkt, *it);
if (lng < -180 || lng > 180) {
throwInvalidPolygonLongitude(*it);
}
++it;
GeographyPointValue::Coord lat = stringToCoord(POLY, wkt, *it);
if (lat < -90 || lat > 90) {
throwInvalidPolygonLatitude(*it);
}
++it;
// Note: This is S2. It takes latitude, longitude, not
// longitude, latitude.
points.push_back(S2LatLng::FromDegrees(lat, lng).ToPoint());
if (*it == ",") {
++it;
// continue to next lat long pair
}
else if (*it != ")") {
throwInvalidWktPoly("unexpected token: '" + (*it) + "'");
}
}
if (it == end) {
// we hit the end of input before the closing parenthesis
throwInvalidWktPoly("unexpected end of input");
}
assert (*it == ")");
// Advance iterator to next token
++it;
if (points.size() < 4) {
throwInvalidWktPoly("A polygon ring must contain at least 4 points (including repeated closing vertex)");
}
const S2Point& first = points.at(0);
const S2Point& last = points.at(points.size() - 1);
if (first != last) {
throwInvalidWktPoly("A polygon ring's first vertex must be equal to its last vertex");
}
// S2 format considers the closing vertex in a loop to be
// implicit, while in WKT it is explicit. Remove the closing
// vertex here to reflect this.
points.pop_back();
// The first is a shell. All others are holes. We need to reverse
// the order of the vertices for holes.
if (!is_shell) {
// Don't touch the first point. We don't want to
// cycle the vertices.
std::reverse(++(points.begin()), points.end());
}
loop->Init(points);
}
