// getBlankTileData returns zero 2d tile data with a given scaling and format.
func (d *Data) getBlankTileImage(uuid dvid.UUID, shape dvid.DataShape, scaling Scaling) (image.Image, error) {
levelSpec, found := d.Levels[scaling]
if !found {
return nil, fmt.Errorf("Could not extract tiles for unspecified scale level %d", scaling)
}
tileW, tileH, err := shape.GetSize2D(levelSpec.TileSize)
if err != nil {
return nil, err
}
source, err := datastore.GetDataByUUID(uuid, d.Source)
if err != nil {
return nil, err
}
src, ok := source.(*imageblk.Data)
if !ok {
return nil, fmt.Errorf("Data instance %q for uuid %q is not imageblk.Data", d.Source, uuid)
}
bytesPerVoxel := src.Values.BytesPerElement()
switch bytesPerVoxel {
case 1, 2, 4, 8:
numBytes := tileW * tileH * bytesPerVoxel
data := make([]byte, numBytes, numBytes)
return dvid.GoImageFromData(data, int(tileW), int(tileH))
default:
return nil, fmt.Errorf("Cannot construct blank tile for data %q with %d bytes/voxel",
d.Source, src.Values.BytesPerElement())
}
}
// NewTKey returns an imagetile-specific key component based on the components of a tile request.
func NewTKey(tile dvid.ChunkPoint3d, plane dvid.DataShape, scale Scaling) storage.TKey {
buf := bytes.NewBuffer(plane.Bytes())
buf.WriteByte(byte(scale))
buf.WriteByte(byte(3))
idx := dvid.IndexZYX(tile)
buf.Write(idx.Bytes())
return buf.Bytes()
}
func (s *Shape) FromShape(shape dvid.DataShape) error {
switch {
case shape.Equals(dvid.XY):
*s = XY
case shape.Equals(dvid.XZ):
*s = XZ
case shape.Equals(dvid.YZ):
*s = YZ
case shape.Equals(dvid.Vol3d):
*s = XYZ
default:
return fmt.Errorf("No Google BrainMaps shape corresponds to DVID %s shape", shape)
}
return nil
}
// GetTileSpec returns a TileSpec for a given scale and dvid Geometry.
func GetTileSpec(scaling Scaling, shape dvid.DataShape) (*TileSpec, error) {
ts := new(TileSpec)
ts.scaling = scaling
switch {
case shape.Equals(dvid.XY):
ts.plane = XY
case shape.Equals(dvid.XZ):
ts.plane = XZ
case shape.Equals(dvid.YZ):
ts.plane = YZ
default:
return nil, fmt.Errorf("No Google BrainMaps slice orientation corresponding to DVID %s shape", shape)
}
return ts, nil
}