osg::Image*
createImage( const TileKey& key, ProgressCallback* progress )
{
if ( !_image.valid() || key.getLevelOfDetail() > getMaxDataLevel() )
return NULL;
GeoImage cropped = _image.crop( key.getExtent(), true, getPixelsPerTile(), getPixelsPerTile() );
return cropped.valid() ? cropped.takeImage() : 0L;
}
GeoImage
ImageLayer::createImageFromTileSource(const TileKey& key,
ProgressCallback* progress,
bool forceFallback,
bool& out_isFallback)
{
// Results:
//
// * return an osg::Image matching the key extent is all goes well;
//
// * return NULL to indicate that the key exceeds the maximum LOD of the source data,
// and that the engine may need to generate a "fallback" tile if necessary;
//
// deprecated:
// * return an "empty image" if the LOD is valid BUT the key does not intersect the
// source's data extents.
out_isFallback = false;
TileSource* source = getTileSource();
if ( !source )
return GeoImage::INVALID;
// If the profiles are different, use a compositing method to assemble the tile.
if ( !key.getProfile()->isEquivalentTo( getProfile() ) )
{
return assembleImageFromTileSource( key, progress, out_isFallback );
}
// Good to go, ask the tile source for an image:
osg::ref_ptr<TileSource::ImageOperation> op = _preCacheOp;
osg::ref_ptr<osg::Image> result;
if ( forceFallback )
{
// check if the tile source has any data coverage for the requested key.
// the LOD is ignore here and checked later
if ( !source->hasDataInExtent( key.getExtent() ) )
{
OE_DEBUG << LC << "createImageFromTileSource: hasDataInExtent(" << key.str() << ") == false" << std::endl;
return GeoImage::INVALID;
}
TileKey finalKey = key;
while( !result.valid() && finalKey.valid() )
{
if ( !source->getBlacklist()->contains( finalKey.getTileId() ) &&
source->hasDataForFallback(finalKey))
{
result = source->createImage( finalKey, op.get(), progress );
if ( result.valid() )
{
if ( finalKey.getLevelOfDetail() != key.getLevelOfDetail() )
{
// crop the fallback image to match the input key, and ensure that it remains the
// same pixel size; because chances are if we're requesting a fallback that we're
// planning to mosaic it later, and the mosaicer requires same-size images.
GeoImage raw( result.get(), finalKey.getExtent() );
GeoImage cropped = raw.crop( key.getExtent(), true, raw.getImage()->s(), raw.getImage()->t(), *_runtimeOptions.driver()->bilinearReprojection() );
result = cropped.takeImage();
}
}
}
if ( !result.valid() )
{
finalKey = finalKey.createParentKey();
out_isFallback = true;
}
}
if ( !result.valid() )
{
result = 0L;
//result = _emptyImage.get();
finalKey = key;
}
}
else
{
// Fail is the image is blacklisted.
if ( source->getBlacklist()->contains( key.getTileId() ) )
{
OE_DEBUG << LC << "createImageFromTileSource: blacklisted(" << key.str() << ")" << std::endl;
return GeoImage::INVALID;
}
if ( !source->hasData( key ) )
{
OE_DEBUG << LC << "createImageFromTileSource: hasData(" << key.str() << ") == false" << std::endl;
return GeoImage::INVALID;
}
result = source->createImage( key, op.get(), progress );
}
// Process images with full alpha to properly support MP blending.
if ( result != 0L && *_runtimeOptions.featherPixels())
{
ImageUtils::featherAlphaRegions( result.get() );
}
// If image creation failed (but was not intentionally canceled),
// blacklist this tile for future requests.
if ( result == 0L && (!progress || !progress->isCanceled()) )
{
source->getBlacklist()->add( key.getTileId() );
}
return GeoImage(result.get(), key.getExtent());
}
