Revision
Map::getElevationLayers( ElevationLayerVector& out_list ) const
{
out_list.reserve( _elevationLayers.size() );
Threading::ScopedReadLock lock( const_cast<Map*>(this)->_mapDataMutex );
for( ElevationLayerVector::const_iterator i = _elevationLayers.begin(); i != _elevationLayers.end(); ++i )
out_list.push_back( i->get() );
return _dataModelRevision;
}
bool
ElevationLayerVector::populateHeightField(osg::HeightField* hf,
const TileKey& key,
const Profile* haeProfile,
ElevationInterpolation interpolation,
ProgressCallback* progress ) const
{
// heightfield must already exist.
if ( !hf )
return false;
// if the caller provided an "HAE map profile", he wants an HAE elevation grid even if
// the map profile has a vertical datum. This is the usual case when building the 3D
// terrain, for example. Construct a temporary key that doesn't have the vertical
// datum info and use that to query the elevation data.
TileKey keyToUse = key;
if ( haeProfile )
{
keyToUse = TileKey(key.getLOD(), key.getTileX(), key.getTileY(), haeProfile );
}
// Collect the valid layers for this tile.
ElevationLayerVector contenders;
ElevationLayerVector offsets;
for(ElevationLayerVector::const_reverse_iterator i = this->rbegin(); i != this->rend(); ++i)
{
ElevationLayer* layer = i->get();
if ( layer->getEnabled() && layer->getVisible() )
{
// calculate the resolution-mapped key (adjusted for tile resolution differential).
TileKey mappedKey =
keyToUse.mapResolution(hf->getNumColumns(), layer->getTileSize());
// Note: isKeyInRange tests the key, but haData tests the mapped key.
// I think that's right!
if ((layer->getTileSource() == 0L) ||
(layer->isKeyInRange(key) && layer->getTileSource()->hasData(mappedKey)))
{
if (layer->isOffset())
offsets.push_back(layer);
else
contenders.push_back(layer);
}
}
}
// nothing? bail out.
if ( contenders.empty() && offsets.empty() )
{
return false;
}
// Sample the layers into our target.
unsigned numColumns = hf->getNumColumns();
unsigned numRows = hf->getNumRows();
double xmin = key.getExtent().xMin();
double ymin = key.getExtent().yMin();
double dx = key.getExtent().width() / (double)(numColumns-1);
double dy = key.getExtent().height() / (double)(numRows-1);
// We will load the actual heightfields on demand. We might not need them all.
GeoHeightFieldVector heightFields(contenders.size());
GeoHeightFieldVector offsetFields(offsets.size());
std::vector<bool> heightFailed (contenders.size(), false);
std::vector<bool> offsetFailed(offsets.size(), false);
const SpatialReference* keySRS = keyToUse.getProfile()->getSRS();
bool realData = false;
for (unsigned c = 0; c < numColumns; ++c)
{
double x = xmin + (dx * (double)c);
for (unsigned r = 0; r < numRows; ++r)
{
double y = ymin + (dy * (double)r);
// Collect elevations from each layer as necessary.
bool resolved = false;
for(int i=0; i<contenders.size() && !resolved; ++i)
{
if ( heightFailed[i] )
continue;
GeoHeightField& layerHF = heightFields[i];
if ( !layerHF.valid() )
{
TileKey mappedKey =
keyToUse.mapResolution(hf->getNumColumns(), contenders[i]->getTileSize());
layerHF = contenders[i]->createHeightField(mappedKey, progress);
if ( !layerHF.valid() )
{
heightFailed[i] = true;
continue;
}
}
// If we actually got a layer then we have real data
realData = true;
float elevation;
if (layerHF.getElevation(keySRS, x, y, interpolation, keySRS, elevation) &&
elevation != NO_DATA_VALUE)
{
resolved = true;
hf->setHeight(c, r, elevation);
}
}
for(int i=offsets.size()-1; i>=0; --i)
{
if ( offsetFailed[i] )
continue;
GeoHeightField& layerHF = offsetFields[i];
if ( !layerHF.valid() )
{
TileKey mappedKey =
keyToUse.mapResolution(hf->getNumColumns(), offsets[i]->getTileSize());
layerHF = offsets[i]->createHeightField(mappedKey, progress);
if ( !layerHF.valid() )
{
offsetFailed[i] = true;
continue;
}
}
// If we actually got a layer then we have real data
realData = true;
float elevation = 0.0f;
if (layerHF.getElevation(keySRS, x, y, interpolation, keySRS, elevation) &&
elevation != NO_DATA_VALUE)
{
hf->getHeight(c, r) += elevation;
}
}
}
}
// Return whether or not we actually read any real data
return realData;
}
