void
ElevationLayer::assembleHeightField(const TileKey& key,
osg::ref_ptr<osg::HeightField>& out_hf,
osg::ref_ptr<NormalMap>& out_normalMap,
ProgressCallback* progress)
{
// Collect the heightfields for each of the intersecting tiles.
GeoHeightFieldVector heightFields;
//Determine the intersecting keys
std::vector< TileKey > intersectingTiles;
if (key.getLOD() > 0u)
{
getProfile()->getIntersectingTiles(key, intersectingTiles);
}
else
{
// LOD is zero - check whether the LOD mapping went out of range, and if so,
// fall back until we get valid tiles. This can happen when you have two
// profiles with very different tile schemes, and the "equivalent LOD"
// surpasses the max data LOD of the tile source.
unsigned numTilesThatMayHaveData = 0u;
int intersectionLOD = getProfile()->getEquivalentLOD(key.getProfile(), key.getLOD());
while (numTilesThatMayHaveData == 0u && intersectionLOD >= 0)
{
intersectingTiles.clear();
getProfile()->getIntersectingTiles(key.getExtent(), intersectionLOD, intersectingTiles);
for (unsigned int i = 0; i < intersectingTiles.size(); ++i)
{
const TileKey& layerKey = intersectingTiles[i];
if (mayHaveData(layerKey) == true)
{
++numTilesThatMayHaveData;
}
}
--intersectionLOD;
}
}
// collect heightfield for each intersecting key. Note, we're hitting the
// underlying tile source here, so there's no vetical datum shifts happening yet.
// we will do that later.
if ( intersectingTiles.size() > 0 )
{
for (unsigned int i = 0; i < intersectingTiles.size(); ++i)
{
const TileKey& layerKey = intersectingTiles[i];
if ( isKeyInLegalRange(layerKey) )
{
osg::ref_ptr<osg::HeightField> hf;
osg::ref_ptr<NormalMap> normalMap;
createImplementation(layerKey, hf, normalMap, progress);
if (hf.valid())
{
heightFields.push_back( GeoHeightField(hf.get(), normalMap.get(), layerKey.getExtent()) );
}
}
}
// If we actually got a HeightField, resample/reproject it to match the incoming TileKey's extents.
if (heightFields.size() > 0)
{
unsigned int width = 0;
unsigned int height = 0;
for (GeoHeightFieldVector::iterator itr = heightFields.begin(); itr != heightFields.end(); ++itr)
{
if (itr->getHeightField()->getNumColumns() > width)
width = itr->getHeightField()->getNumColumns();
if (itr->getHeightField()->getNumRows() > height)
height = itr->getHeightField()->getNumRows();
}
//Now sort the heightfields by resolution to make sure we're sampling the highest resolution one first.
std::sort( heightFields.begin(), heightFields.end(), GeoHeightField::SortByResolutionFunctor());
out_hf = new osg::HeightField();
out_hf->allocate(width, height);
out_normalMap = new NormalMap(width, height);
//Go ahead and set up the heightfield so we don't have to worry about it later
double minx, miny, maxx, maxy;
key.getExtent().getBounds(minx, miny, maxx, maxy);
double dx = (maxx - minx)/(double)(width-1);
double dy = (maxy - miny)/(double)(height-1);
//Create the new heightfield by sampling all of them.
for (unsigned int c = 0; c < width; ++c)
{
double x = minx + (dx * (double)c);
for (unsigned r = 0; r < height; ++r)
{
double y = miny + (dy * (double)r);
//For each sample point, try each heightfield. The first one with a valid elevation wins.
float elevation = NO_DATA_VALUE;
osg::Vec3 normal(0,0,1);
for (GeoHeightFieldVector::iterator itr = heightFields.begin(); itr != heightFields.end(); ++itr)
{
// get the elevation value, at the same time transforming it vertically into the
// requesting key's vertical datum.
float e = 0.0;
osg::Vec3 n;
if (itr->getElevationAndNormal(key.getExtent().getSRS(), x, y, INTERP_BILINEAR, key.getExtent().getSRS(), e, n))
{
elevation = e;
normal = n;
break;
}
}
out_hf->setHeight( c, r, elevation );
out_normalMap->set( c, r, normal );
}
}
}
else
{
//if (progress && progress->message().empty())
// progress->message() = "assemble yielded no heightfields";
}
}
else
{
//if (progress && progress->message().empty())
// progress->message() = "assemble yielded no intersecting tiles";
}
// If the progress was cancelled clear out any of the output data.
if (progress && progress->isCanceled())
{
out_hf = 0;
out_normalMap = 0;
}
}
osg::HeightField*
ElevationLayer::assembleHeightFieldFromTileSource(const TileKey& key,
ProgressCallback* progress)
{
osg::HeightField* result = 0L;
// Collect the heightfields for each of the intersecting tiles.
GeoHeightFieldVector heightFields;
//Determine the intersecting keys
std::vector< TileKey > intersectingTiles;
getProfile()->getIntersectingTiles( key, intersectingTiles );
// collect heightfield for each intersecting key. Note, we're hitting the
// underlying tile source here, so there's no vetical datum shifts happening yet.
// we will do that later.
if ( intersectingTiles.size() > 0 )
{
for (unsigned int i = 0; i < intersectingTiles.size(); ++i)
{
const TileKey& layerKey = intersectingTiles[i];
if ( isKeyValid(layerKey) )
{
osg::HeightField* hf = createHeightFieldFromTileSource( layerKey, progress );
if ( hf )
{
heightFields.push_back( GeoHeightField(hf, layerKey.getExtent()) );
}
else
{
//We couldn't get a heightfield at the given key so fall back on parent tiles
TileKey parentKey = layerKey.createParentKey();
while (!hf && parentKey.valid())
{
hf = createHeightFieldFromTileSource( parentKey, progress );
if (hf)
{
heightFields.push_back( GeoHeightField(hf, parentKey.getExtent()) );
break;
}
parentKey = parentKey.createParentKey();
}
}
}
}
}
// If we actually got a HeightField, resample/reproject it to match the incoming TileKey's extents.
if (heightFields.size() > 0)
{
unsigned int width = 0;
unsigned int height = 0;
for (GeoHeightFieldVector::iterator itr = heightFields.begin(); itr != heightFields.end(); ++itr)
{
if (itr->getHeightField()->getNumColumns() > width)
width = itr->getHeightField()->getNumColumns();
if (itr->getHeightField()->getNumRows() > height)
height = itr->getHeightField()->getNumRows();
}
result = new osg::HeightField();
result->allocate(width, height);
//Go ahead and set up the heightfield so we don't have to worry about it later
double minx, miny, maxx, maxy;
key.getExtent().getBounds(minx, miny, maxx, maxy);
double dx = (maxx - minx)/(double)(width-1);
double dy = (maxy - miny)/(double)(height-1);
//Create the new heightfield by sampling all of them.
for (unsigned int c = 0; c < width; ++c)
{
double x = minx + (dx * (double)c);
for (unsigned r = 0; r < height; ++r)
{
double y = miny + (dy * (double)r);
//For each sample point, try each heightfield. The first one with a valid elevation wins.
float elevation = NO_DATA_VALUE;
for (GeoHeightFieldVector::iterator itr = heightFields.begin(); itr != heightFields.end(); ++itr)
{
// get the elevation value, at the same time transforming it vertically into the
// requesting key's vertical datum.
float e = 0.0;
if (itr->getElevation(key.getExtent().getSRS(), x, y, INTERP_BILINEAR, key.getExtent().getSRS(), e))
{
elevation = e;
break;
}
}
result->setHeight( c, r, elevation );
}
}
}
return result;
}