private IList <Way> ProcessWays(QueryParameters queryParameters, int numberOfWays, BoundingBox boundingBox, bool filterRequired, double tileLatitude, double tileLongitude, ReadBuffer readBuffer)
{
IList <Way> ways = new List <Way>();
Tag[] wayTags = this.mapFileHeader.MapFileInfo.WayTags;
// Extend BoundingBox about wayFilterDistance meters, so that ways crossing the border added
double verticalExpansion = PointUtils.LatitudeDistance(wayFilterDistance);
double horizontalExpansion = PointUtils.LongitudeDistance(wayFilterDistance, Math.Max(Math.Abs(boundingBox.MinY), Math.Abs(boundingBox.MaxY)));
double minLat = Math.Max(MercatorProjection.LATITUDE_MIN, boundingBox.MinY - verticalExpansion);
double minLon = Math.Max(-180, boundingBox.MinX - horizontalExpansion);
double maxLat = Math.Min(MercatorProjection.LATITUDE_MAX, boundingBox.MaxY + verticalExpansion);
double maxLon = Math.Min(180, boundingBox.MaxX + horizontalExpansion);
BoundingBox wayFilterBbox = new BoundingBox(minLon, minLat, maxLon, maxLat);
for (int elementCounter = numberOfWays; elementCounter != 0; --elementCounter)
{
if (this.mapFileHeader.MapFileInfo.DebugFile)
{
// get and check the way signature
string signatureWay = readBuffer.ReadUTF8EncodedString(SIGNATURE_LENGTH_WAY);
if (!signatureWay.StartsWith("---WayStart", StringComparison.Ordinal))
{
Logger.Log(LogLevel.Warning, "invalid way signature: " + signatureWay);
return(null);
}
}
// get the size of the way (VBE-U)
int wayDataSize = readBuffer.ReadUnsignedInt();
if (wayDataSize < 0)
{
Logger.Log(LogLevel.Warning, "invalid way data size: " + wayDataSize);
return(null);
}
if (queryParameters.useTileBitmask)
{
// get the way tile bitmask (2 bytes)
int tileBitmask = readBuffer.ReadShort();
// check if the way is inside the requested tile
if ((queryParameters.queryTileBitmask & tileBitmask) == 0)
{
// skip the rest of the way and continue with the next way
readBuffer.SkipBytes(wayDataSize - 2);
continue;
}
}
else
{
// ignore the way tile bitmask (2 bytes)
readBuffer.SkipBytes(2);
}
// get the special byte which encodes multiple flags
sbyte specialByte = readBuffer.ReadByte();
// bit 1-4 represent the layer
sbyte layer = (sbyte)((int)((uint)(specialByte & WAY_LAYER_BITMASK) >> WAY_LAYER_SHIFT));
// bit 5-8 represent the number of tag IDs
sbyte numberOfTags = (sbyte)(specialByte & WAY_NUMBER_OF_TAGS_BITMASK);
IList <Tag> tags = new List <Tag>();
for (sbyte tagIndex = numberOfTags; tagIndex != 0; --tagIndex)
{
int tagId = readBuffer.ReadUnsignedInt();
if (tagId < 0 || tagId >= wayTags.Length)
{
Logger.Log(LogLevel.Warning, "invalid way tag ID: " + tagId);
return(null);
}
tags.Add(wayTags[tagId]);
}
// get the feature bitmask (1 byte)
sbyte featureByte = readBuffer.ReadByte();
// bit 1-6 enable optional features
bool featureName = (featureByte & WAY_FEATURE_NAME) != 0;
bool featureHouseNumber = (featureByte & WAY_FEATURE_HOUSE_NUMBER) != 0;
bool featureRef = (featureByte & WAY_FEATURE_REF) != 0;
bool featureLabelPosition = (featureByte & WAY_FEATURE_LABEL_POSITION) != 0;
bool featureWayDataBlocksByte = (featureByte & WAY_FEATURE_DATA_BLOCKS_BYTE) != 0;
bool featureWayDoubleDeltaEncoding = (featureByte & WAY_FEATURE_DOUBLE_DELTA_ENCODING) != 0;
// check if the way has a name
if (featureName)
{
tags.Add(new Tag(TAG_KEY_NAME, ExtractLocalized(readBuffer.ReadUTF8EncodedString())));
}
// check if the way has a house number
if (featureHouseNumber)
{
tags.Add(new Tag(TAG_KEY_HOUSE_NUMBER, readBuffer.ReadUTF8EncodedString()));
}
// check if the way has a reference
if (featureRef)
{
tags.Add(new Tag(TAG_KEY_REF, readBuffer.ReadUTF8EncodedString()));
}
Point labelPosition = ReadOptionalLabelPosition(tileLatitude, tileLongitude, featureLabelPosition, readBuffer);
int wayDataBlocks = ReadOptionalWayDataBlocksByte(featureWayDataBlocksByte, readBuffer);
if (wayDataBlocks < 1)
{
Logger.Log(LogLevel.Warning, "invalid number of way data blocks: " + wayDataBlocks);
return(null);
}
for (int wayDataBlock = 0; wayDataBlock < wayDataBlocks; ++wayDataBlock)
{
List <List <Point> > wayNodes = ProcessWayDataBlock(tileLatitude, tileLongitude, featureWayDoubleDeltaEncoding, readBuffer);
if (wayNodes != null)
{
if (filterRequired && wayFilterEnabled)
{
double minX = double.MaxValue;
double minY = double.MaxValue;
double maxX = 0;
double maxY = 0;
for (int i = 0; i < wayNodes.Count; i++)
{
for (int j = 0; j < wayNodes[i].Count; j++)
{
minX = Math.Min(minX, wayNodes[i][j].X);
minY = Math.Min(minY, wayNodes[i][j].Y);
maxX = Math.Max(maxX, wayNodes[i][j].X);
maxY = Math.Max(maxY, wayNodes[i][j].Y);
}
}
if (!wayFilterBbox.Intersects(new BoundingBox(minX, minY, maxX, maxY)))
{
continue;
}
}
ways.Add(new Way(layer, tags, wayNodes, labelPosition));
}
}
}
return(ways);
}
private Point ReadOptionalLabelPosition(double tileLatitude, double tileLongitude, bool featureLabelPosition, ReadBuffer readBuffer)
{
if (featureLabelPosition)
{
// get the label position latitude offset (VBE-S)
double latitude = tileLatitude + PointUtils.MicrodegreesToDegrees(readBuffer.ReadSignedInt());
// get the label position longitude offset (VBE-S)
double longitude = tileLongitude + PointUtils.MicrodegreesToDegrees(readBuffer.ReadSignedInt());
return(new Point(longitude, latitude));
}
return(null);
}
private List <List <Point> > ProcessWayDataBlock(double tileLatitude, double tileLongitude, bool doubleDeltaEncoding, ReadBuffer readBuffer)
{
// get and check the number of way coordinate blocks (VBE-U)
int numberOfWayCoordinateBlocks = readBuffer.ReadUnsignedInt();
if (numberOfWayCoordinateBlocks < 1 || numberOfWayCoordinateBlocks > short.MaxValue)
{
Logger.Log(LogLevel.Warning, "invalid number of way coordinate blocks: " + numberOfWayCoordinateBlocks);
return(null);
}
// create the array which will store the different way coordinate blocks
List <List <Point> > wayCoordinates = new List <List <Point> >(numberOfWayCoordinateBlocks);
// read the way coordinate blocks
for (int coordinateBlock = 0; coordinateBlock < numberOfWayCoordinateBlocks; ++coordinateBlock)
{
// get and check the number of way nodes (VBE-U)
int numberOfWayNodes = readBuffer.ReadUnsignedInt();
if (numberOfWayNodes < 2 || numberOfWayNodes > short.MaxValue)
{
Logger.Log(LogLevel.Warning, "invalid number of way nodes: " + numberOfWayNodes);
// returning null here will actually leave the tile blank as the
// position on the ReadBuffer will not be advanced correctly. However,
// it will not crash the app.
return(null);
}
// create the array which will store the current way segment
List <Point> waySegment = new List <Point>(numberOfWayNodes);
if (doubleDeltaEncoding)
{
decodeWayNodesDoubleDelta(waySegment, tileLatitude, tileLongitude, readBuffer);
}
else
{
decodeWayNodesSingleDelta(waySegment, tileLatitude, tileLongitude, readBuffer);
}
wayCoordinates.Add(waySegment);
}
return(wayCoordinates);
}
private IList <PointOfInterest> ProcessPOIs(double tileLatitude, double tileLongitude, int numberOfPois, BoundingBox boundingBox, bool filterRequired, ReadBuffer readBuffer)
{
IList <PointOfInterest> pois = new List <PointOfInterest>();
Tag[] poiTags = this.mapFileHeader.MapFileInfo.PoiTags;
for (int elementCounter = numberOfPois; elementCounter != 0; --elementCounter)
{
if (this.mapFileHeader.MapFileInfo.DebugFile)
{
// get and check the POI signature
string signaturePoi = readBuffer.ReadUTF8EncodedString(SIGNATURE_LENGTH_POI);
if (!signaturePoi.StartsWith("***POIStart", StringComparison.Ordinal))
{
Logger.Log(LogLevel.Warning, "invalid POI signature: " + signaturePoi);
return(null);
}
}
// get the POI latitude offset (VBE-S)
double latitude = tileLatitude + PointUtils.MicrodegreesToDegrees(readBuffer.ReadSignedInt());
// get the POI longitude offset (VBE-S)
double longitude = tileLongitude + PointUtils.MicrodegreesToDegrees(readBuffer.ReadSignedInt());
// get the special byte which encodes multiple flags
sbyte specialByte = readBuffer.ReadByte();
// bit 1-4 represent the layer with
sbyte layer = (sbyte)((int)((uint)(specialByte & POI_LAYER_BITMASK) >> POI_LAYER_SHIFT));
// bit 5-8 represent the number of tag IDs
sbyte numberOfTags = (sbyte)(specialByte & POI_NUMBER_OF_TAGS_BITMASK);
IList <Tag> tags = new List <Tag>();
// get the tag IDs (VBE-U)
for (sbyte tagIndex = numberOfTags; tagIndex != 0; --tagIndex)
{
int tagId = readBuffer.ReadUnsignedInt();
if (tagId < 0 || tagId >= poiTags.Length)
{
Logger.Log(LogLevel.Warning, "invalid POI tag ID: " + tagId);
return(null);
}
tags.Add(poiTags[tagId]);
}
// get the feature bitmask (1 byte)
sbyte featureByte = readBuffer.ReadByte();
// bit 1-3 enable optional features
bool featureName = (featureByte & POI_FEATURE_NAME) != 0;
bool featureHouseNumber = (featureByte & POI_FEATURE_HOUSE_NUMBER) != 0;
bool featureElevation = (featureByte & POI_FEATURE_ELEVATION) != 0;
// check if the POI has a name
if (featureName)
{
tags.Add(new Tag(TAG_KEY_NAME, ExtractLocalized(readBuffer.ReadUTF8EncodedString())));
}
// check if the POI has a house number
if (featureHouseNumber)
{
tags.Add(new Tag(TAG_KEY_HOUSE_NUMBER, readBuffer.ReadUTF8EncodedString()));
}
// check if the POI has an elevation
if (featureElevation)
{
tags.Add(new Tag(TAG_KEY_ELE, Convert.ToString(readBuffer.ReadSignedInt())));
}
Point position = new Point(longitude, latitude);
// depending on the zoom level configuration the poi can lie outside
// the tile requested, we filter them out here
if (!filterRequired || boundingBox.Contains(position))
{
pois.Add(new PointOfInterest(layer, tags, position));
}
}
return(pois);
}
private MapReadResult ProcessBlocks(QueryParameters queryParameters, SubFileParameter subFileParameter, BoundingBox boundingBox)
{
bool queryIsWater = true;
bool queryReadWaterInfo = false;
MapReadResult mapFileReadResult = new MapReadResult();
// read and process all blocks from top to bottom and from left to right
for (long row = queryParameters.fromBlockY; row <= queryParameters.toBlockY; ++row)
{
for (long column = queryParameters.fromBlockX; column <= queryParameters.toBlockX; ++column)
{
// calculate the actual block number of the needed block in the file
long blockNumber = row * subFileParameter.BlocksWidth + column;
// get the current index entry
long currentBlockIndexEntry = this.databaseIndexCache.GetIndexEntry(subFileParameter, blockNumber);
// check if the current query would still return a water tile
if (queryIsWater)
{
// check the water flag of the current block in its index entry
queryIsWater &= (currentBlockIndexEntry & BITMASK_INDEX_WATER) != 0;
queryReadWaterInfo = true;
}
// get and check the current block pointer
long currentBlockPointer = currentBlockIndexEntry & BITMASK_INDEX_OFFSET;
if (currentBlockPointer < 1 || currentBlockPointer > subFileParameter.SubFileSize)
{
Logger.Log(LogLevel.Warning, "invalid current block pointer: " + currentBlockPointer);
Logger.Log(LogLevel.Warning, "subFileSize: " + subFileParameter.SubFileSize);
return(null);
}
long nextBlockPointer;
// check if the current block is the last block in the file
if (blockNumber + 1 == subFileParameter.NumberOfBlocks)
{
// set the next block pointer to the end of the file
nextBlockPointer = subFileParameter.SubFileSize;
}
else
{
// get and check the next block pointer
nextBlockPointer = this.databaseIndexCache.GetIndexEntry(subFileParameter, blockNumber + 1) & BITMASK_INDEX_OFFSET;
if (nextBlockPointer > subFileParameter.SubFileSize)
{
Logger.Log(LogLevel.Warning, "invalid next block pointer: " + nextBlockPointer);
Logger.Log(LogLevel.Warning, "sub-file size: " + subFileParameter.SubFileSize);
return(null);
}
}
// calculate the size of the current block
int currentBlockSize = (int)(nextBlockPointer - currentBlockPointer);
if (currentBlockSize < 0)
{
Logger.Log(LogLevel.Warning, "current block size must not be negative: " + currentBlockSize);
return(null);
}
else if (currentBlockSize == 0)
{
// the current block is empty, continue with the next block
continue;
}
else if (currentBlockSize > ReadBuffer.MaximumBufferSize)
{
// the current block is too large, continue with the next block
Logger.Log(LogLevel.Warning, "current block size too large: " + currentBlockSize);
continue;
}
else if (currentBlockPointer + currentBlockSize > this.fileSize)
{
Logger.Log(LogLevel.Warning, "current block largher than file size: " + currentBlockSize);
return(null);
}
// read the current block into the buffer
ReadBuffer readBuffer = new ReadBuffer(inputStream);
if (!readBuffer.ReadFromStream(subFileParameter.StartAddress + currentBlockPointer, currentBlockSize))
{
// skip the current block
Logger.Log(LogLevel.Warning, "reading current block has failed: " + currentBlockSize);
return(null);
}
// calculate the top-left coordinates of the underlying tile
double tileLatitude = MercatorProjection.TileYToLatitude(subFileParameter.BoundaryTileTop + row, subFileParameter.BaseZoomLevel);
double tileLongitude = MercatorProjection.TileXToLongitude(subFileParameter.BoundaryTileLeft + column, subFileParameter.BaseZoomLevel);
try
{
PoiWayBundle poiWayBundle = ProcessBlock(queryParameters, subFileParameter, boundingBox, tileLatitude, tileLongitude, readBuffer);
if (poiWayBundle != null)
{
mapFileReadResult.Add(poiWayBundle);
}
}
catch (System.IndexOutOfRangeException e)
{
Logger.Log(LogLevel.Error, e.Message, e);
}
}
}
// the query is finished, was the water flag set for all blocks?
if (queryIsWater && queryReadWaterInfo)
{
// Deprecate water tiles rendering
// mapFileReadResult.IsWater = true;
}
return(mapFileReadResult);
}
private PoiWayBundle ProcessBlock(QueryParameters queryParameters, SubFileParameter subFileParameter, BoundingBox boundingBox, double tileLatitude, double tileLongitude, ReadBuffer readBuffer)
{
if (!ProcessBlockSignature(readBuffer))
{
return(null);
}
int[][] zoomTable = ReadZoomTable(subFileParameter, readBuffer);
int zoomTableRow = queryParameters.queryZoomLevel - subFileParameter.ZoomLevelMin;
int poisOnQueryZoomLevel = zoomTable[zoomTableRow][0];
int waysOnQueryZoomLevel = zoomTable[zoomTableRow][1];
// get the relative offset to the first stored way in the block
int firstWayOffset = readBuffer.ReadUnsignedInt();
if (firstWayOffset < 0)
{
Logger.Log(LogLevel.Warning, INVALID_FIRST_WAY_OFFSET + firstWayOffset);
return(null);
}
// add the current buffer position to the relative first way offset
firstWayOffset += readBuffer.BufferPosition;
if (firstWayOffset > readBuffer.BufferSize)
{
Logger.Log(LogLevel.Warning, INVALID_FIRST_WAY_OFFSET + firstWayOffset);
return(null);
}
bool filterRequired = queryParameters.queryZoomLevel > subFileParameter.BaseZoomLevel;
IList <PointOfInterest> pois = ProcessPOIs(tileLatitude, tileLongitude, poisOnQueryZoomLevel, boundingBox, filterRequired, readBuffer);
if (pois == null)
{
return(null);
}
// finished reading POIs, check if the current buffer position is valid
if (readBuffer.BufferPosition > firstWayOffset)
{
Logger.Log(LogLevel.Warning, "invalid buffer position: " + readBuffer.BufferPosition);
return(null);
}
// move the pointer to the first way
readBuffer.BufferPosition = firstWayOffset;
IList <Way> ways = ProcessWays(queryParameters, waysOnQueryZoomLevel, boundingBox, filterRequired, tileLatitude, tileLongitude, readBuffer);
if (ways == null)
{
return(null);
}
return(new PoiWayBundle(pois, ways));
}
private void decodeWayNodesSingleDelta(List <Point> waySegment, double tileLatitude, double tileLongitude, ReadBuffer readBuffer)
{
// get the first way node latitude single-delta offset (VBE-S)
double wayNodeLatitude = tileLatitude + PointUtils.MicrodegreesToDegrees(readBuffer.ReadSignedInt());
// get the first way node longitude single-delta offset (VBE-S)
double wayNodeLongitude = tileLongitude + PointUtils.MicrodegreesToDegrees(readBuffer.ReadSignedInt());
// store the first way node
waySegment.Add(new Point(wayNodeLongitude, wayNodeLatitude));
for (int wayNodesIndex = 1; wayNodesIndex < waySegment.Capacity; ++wayNodesIndex)
{
// get the way node latitude offset (VBE-S)
wayNodeLatitude = wayNodeLatitude + PointUtils.MicrodegreesToDegrees(readBuffer.ReadSignedInt());
// get the way node longitude offset (VBE-S)
wayNodeLongitude = wayNodeLongitude + PointUtils.MicrodegreesToDegrees(readBuffer.ReadSignedInt());
// Decoding near international date line can return values slightly outside valid [-180°, 180°] due to calculation precision
if (wayNodeLongitude < PointUtils.LONGITUDE_MIN &&
(PointUtils.LONGITUDE_MIN - wayNodeLongitude) < 0.001)
{
wayNodeLongitude = PointUtils.LONGITUDE_MIN;
}
else if (wayNodeLongitude > PointUtils.LONGITUDE_MAX &&
(wayNodeLongitude - PointUtils.LONGITUDE_MAX) < 0.001)
{
wayNodeLongitude = PointUtils.LONGITUDE_MAX;
}
waySegment.Add(new Point(wayNodeLongitude, wayNodeLatitude));
}
}