void
KML_Geometry::parseStyle( xml_node<>* node, KMLContext& cx, Style& style )
{
_extrude = getValue(node, "extrude") == "1";
_tessellate = getValue(node, "tessellate") == "1";
std::string am = getValue(node, "altitudemode");
if ( am.empty() )
am = "clampToGround"; // default.
bool isPoly = _geom.valid() && _geom->getComponentType() == Geometry::TYPE_POLYGON;
bool isLine = _geom.valid() && _geom->getComponentType() == Geometry::TYPE_LINESTRING;
// Resolve the correct altitude symbol. CLAMP_TO_TERRAIN is the default, but the
// technique will depend on the geometry's type and setup.
AltitudeSymbol* alt = style.getOrCreate<AltitudeSymbol>();
alt->clamping() = alt->CLAMP_TO_TERRAIN;
// Compute some info about the geometry
// Are all of the elevations zero?
bool zeroElev = true;
// Are all of the the elevations the same?
bool sameElev = true;
double maxElevation = -DBL_MAX;
//if ( isPoly ) //compute maxElevation also for line strings for extrusion height
{
bool first = true;
double e = 0.0;
ConstGeometryIterator gi( _geom.get(), false );
while(gi.hasMore() )
{
const Geometry* g = gi.next();
for( Geometry::const_iterator ji = g->begin(); ji != g->end(); ++ji )
{
if ( !osg::equivalent(ji->z(), 0.0) )
zeroElev = false;
if (first)
{
first = false;
e = ji->z();
}
else
{
if (!osg::equivalent(e, ji->z()))
{
sameElev = false;
}
}
if (ji->z() > maxElevation) maxElevation = ji->z();
}
}
}
// clamp to ground mode:
if ( am == "clampToGround" )
{
if ( _extrude )
{
alt->technique() = alt->TECHNIQUE_MAP;
}
else if ( isPoly )
{
alt->technique() = alt->TECHNIQUE_DRAPE;
}
else if ( isLine)
{
alt->technique() = alt->TECHNIQUE_DRAPE; // or could be GPU.
}
else // line or point
{
alt->technique() = alt->TECHNIQUE_SCENE;
}
// extrusion is not compatible with clampToGround.
_extrude = false;
}
// "relativeToGround" means the coordinates' Z values are relative to the Z of the
// terrain at that point. NOTE: GE flattens rooftops in this mode when extrude=1,
// which seems wrong..
else if ( am == "relativeToGround" )
{
alt->clamping() = alt->CLAMP_RELATIVE_TO_TERRAIN;
if (isPoly)
{
// If all of the verts have the same elevation then assume that it should be clamped at the centroid and not per vertex.
if (sameElev)
{
alt->binding() = AltitudeSymbol::BINDING_CENTROID;
}
if ( _extrude )
{
alt->technique() = alt->TECHNIQUE_MAP;
}
else
{
alt->technique() = alt->TECHNIQUE_SCENE;
if ( zeroElev )
{
alt->clamping() = alt->CLAMP_TO_TERRAIN;
alt->technique() = alt->TECHNIQUE_DRAPE;
}
}
}
}
// "absolute" means to treat the Z values as-is
else if ( am == "absolute" )
{
alt->clamping() = AltitudeSymbol::CLAMP_NONE;
}
if ( _extrude )
{
ExtrusionSymbol* es = style.getOrCreate<ExtrusionSymbol>();
es->flatten() = false;
if (*alt->clamping() == AltitudeSymbol::CLAMP_NONE)
{
// Set the height to the max elevation + the approx depth of the mariana trench so that it will extend low enough to be always go to the surface of the earth.
// This lets us avoid clamping absolute absolute extruded polygons completely.
es->height() = -(maxElevation + 11100.0);
}
}
else
{
// remove polystyle since it doesn't apply to non-extruded lines and points
if ( !isPoly )
{
style.remove<PolygonSymbol>();
}
}
}
