/// <summary>
/// This creates a window from this raster. The window will still save to the same
/// source file, but only has access to a small window of data, so it can be loaded like a buffer.
/// The georeferenced extents will be for the new window, not the original raster. startRow and endRow
/// will exist in the new raster, however, so that it knows how to copy values back to the original raster.
/// </summary>
/// <param name="startRow">The 0 based integer index of the top row to get from this raster. If this raster is itself a window, 0 represents the startRow from the file.</param>
/// <param name="endRow">The integer index of the bottom row to get from this raster. The largest allowed value is NumRows - 1.</param>
/// <param name="startColumn">The 0 based integer index of the leftmost column to get from this raster. If this raster is a window, 0 represents the startColumn from the file.</param>
/// <param name="endColumn">The 0 based integer index of the rightmost column to get from this raster. The largest allowed value is NumColumns - 1</param>
/// <param name="inRam">Boolean. If this is true and the window is small enough, a copy of the values will be loaded into memory.</param>
/// <returns>An implementation of IRaster</returns>
public new IRaster GetWindow(int startRow, int endRow, int startColumn, int endColumn, bool inRam)
{
int numCols = endColumn - startColumn + 1;
int numRows = endRow - startRow + 1;
BinaryShortRaster result = new BinaryShortRaster();
result.Filename = Filename;
result.Projection = Projection;
result.NumRows = endRow - startRow + 1;
result.NumColumns = endColumn - startColumn + 1;
result.NumRowsInFile = NumRowsInFile;
result.NumColumnsInFile = NumColumnsInFile;
result.NoDataValue = NoDataValue;
result.StartColumn = startColumn + StartColumn;
result.StartRow = startRow + StartRow;
result.EndColumn = endColumn + StartColumn;
result.EndRow = EndRow + StartRow;
// Reposition the "raster" so that it matches the window, not the whole raster
// X = [0] + [1] * column + [2] * row;
// Y = [3] + [4] * column + [5] * row;
result.Bounds = new RasterBounds(result.NumRows, result.NumColumns, new double[6]);
result.Bounds.AffineCoefficients[0] = Bounds.AffineCoefficients[0] +
Bounds.AffineCoefficients[1]*startColumn +
Bounds.AffineCoefficients[2]*startRow;
result.Bounds.AffineCoefficients[1] = Bounds.AffineCoefficients[1];
result.Bounds.AffineCoefficients[2] = Bounds.AffineCoefficients[2];
result.Bounds.AffineCoefficients[3] = Bounds.AffineCoefficients[3] +
Bounds.AffineCoefficients[4]*startColumn +
Bounds.AffineCoefficients[5]*startRow;
result.Bounds.AffineCoefficients[4] = Bounds.AffineCoefficients[4];
result.Bounds.AffineCoefficients[5] = Bounds.AffineCoefficients[5];
// Now we can copy any values currently in memory.
if (IsInRam)
{
//result.ReadHeader(Filename);
result.Data = new short[numRows][];
ProgressMeter pm = new ProgressMeter(ProgressHandler, MessageStrings.CopyingValues, endRow);
pm.StartValue = startRow;
// copy values directly using both data structures
for (int row = 0; row < numRows; row++)
{
result.Data[row] = new short[numCols];
for (int col = 0; col < numCols; col++)
{
result.Data[row][col] = Data[startRow + row][startColumn + col];
}
pm.CurrentValue = row;
}
pm.Reset();
}
else
result.OpenWindow(Filename, startRow, endRow, startColumn, endColumn, inRam);
result.Value = new ShortValueGrid(result);
return result;
}
/// <summary>
/// This creates a completely new raster from the windowed domain on the original raster. This new raster
/// will have a separate source file, and values like NumRowsInFile will correspond to the newly created file.
/// All the values will be copied to the new source file. If inRam = true and the new raster is small enough,
/// the raster values will be loaded into memory.
/// </summary>
/// <param name="filename"></param>
/// <param name="startRow">The 0 based integer index of the top row to copy from this raster. If this raster is itself a window, 0 represents the startRow from the file.</param>
/// <param name="endRow">The integer index of the bottom row to copy from this raster. The largest allowed value is NumRows - 1.</param>
/// <param name="startColumn">The 0 based integer index of the leftmost column to copy from this raster. If this raster is a window, 0 represents the startColumn from the file.</param>
/// <param name="endColumn">The 0 based integer index of the rightmost column to copy from this raster. The largest allowed value is NumColumns - 1</param>
/// <param name="copyValues">If this is true, the valeus are saved to the file. If this is false and the data can be loaded into Ram, no file handling is done. Otherwise, a file of NoData values is created.</param>
/// <param name="inRam">Boolean. If this is true and the window is small enough, a copy of the values will be loaded into memory.</param>
/// <returns>An implementation of IRaster</returns>
public new IRaster CopyWindow(string filename, int startRow, int endRow, int startColumn, int endColumn,
bool copyValues, bool inRam)
{
int numCols = endColumn - startColumn + 1;
int numRows = endRow - startRow + 1;
BinaryShortRaster result = new BinaryShortRaster(filename, numCols, numRows, inRam);
result.Projection = Projection;
// The affine coefficients defining the world file are the same except that they are translated over. Only the position of the
// upper left corner changes. Everything else is the same as the previous raster.
// X = [0] + [1] * column + [2] * row;
// Y = [3] + [4] * column + [5] * row;
result.Bounds = new RasterBounds(result.NumRows, result.NumColumns, new double[6]);
result.Bounds.AffineCoefficients[0] = Bounds.AffineCoefficients[0] +
Bounds.AffineCoefficients[1]*startColumn +
Bounds.AffineCoefficients[2]*startRow;
result.Bounds.AffineCoefficients[1] = Bounds.AffineCoefficients[1];
result.Bounds.AffineCoefficients[2] = Bounds.AffineCoefficients[2];
result.Bounds.AffineCoefficients[3] = Bounds.AffineCoefficients[3] +
Bounds.AffineCoefficients[4]*startColumn +
Bounds.AffineCoefficients[5]*startRow;
result.Bounds.AffineCoefficients[4] = Bounds.AffineCoefficients[4];
result.Bounds.AffineCoefficients[5] = Bounds.AffineCoefficients[5];
if (IsInRam)
{
ProgressMeter pm = new ProgressMeter(ProgressHandler, MessageStrings.CopyingValues, numRows);
// copy values directly using both data structures
for (int row = 0; row < numRows; row++)
{
for (int col = 0; col < numCols; col++)
{
result.Data[row][col] = Data[startRow + row][startColumn + col];
}
pm.CurrentValue = row;
}
pm.Reset();
if (result.IsInRam == false)
{
// Force the result raster to write itself to a file and then purge its memory.
result.Write(filename);
result.Data = null;
}
}
else
{
if (result.IsInRam)
{
// the source is not in memory, so we just read the values from the file as if opening it directly from the file.
result.OpenWindow(Filename, startRow, endRow, startColumn, endColumn, true);
}
else
{
// Both sources are file based so we basically copy rows of bytes from one to the other.
FileStream source = new FileStream(Filename, FileMode.Open, FileAccess.Read, FileShare.Read);
result.WriteHeader(filename);
FileStream dest = new FileStream(filename, FileMode.Append, FileAccess.Write, FileShare.None);
source.Seek(HeaderSize, SeekOrigin.Begin);
BinaryReader bReader = new BinaryReader(source);
BinaryWriter bWriter = new BinaryWriter(dest);
ProgressMeter pm = new ProgressMeter(ProgressHandler, MessageStrings.CopyingValues, numRows);
// copy values directly using both data structures
source.Seek(NumColumnsInFile*startRow*ByteSize, SeekOrigin.Current);
for (int row = 0; row < numRows; row++)
{
source.Seek(numCols*ByteSize, SeekOrigin.Current);
byte[] rowData = bReader.ReadBytes(ByteSize*numCols);
bWriter.Write(rowData);
source.Seek(NumColumnsInFile - endColumn + 1, SeekOrigin.Current);
bWriter.Flush();
pm.CurrentValue = row;
}
pm.Reset();
}
}
return result;
}
