private static void DrawToBitmapT <T>(IRaster raster, T noData, Func <int, int, T> getValue, Func <int, byte> getByte, Action <int, byte> setByte, IRasterSymbolizer rasterSymbolizer, int stride, ProgressMeter pm)
where T : struct, IEquatable <T>, IComparable <T>
{
if (raster == null)
{
throw new ArgumentNullException(nameof(raster));
}
if (rasterSymbolizer == null)
{
throw new ArgumentNullException(nameof(rasterSymbolizer));
}
if (rasterSymbolizer.Scheme.Categories == null || rasterSymbolizer.Scheme.Categories.Count == 0)
{
return;
}
float[][] hillshade = null;
if (rasterSymbolizer.ShadedRelief.IsUsed)
{
pm.BaseMessage = "Calculating Shaded Relief";
hillshade = rasterSymbolizer.HillShade ?? raster.CreateHillShadeT(getValue, rasterSymbolizer.ShadedRelief, pm);
}
pm.BaseMessage = "Calculating Colors";
var sets = GetColorSets <T>(rasterSymbolizer.Scheme.Categories);
var noDataColor = Argb.FromColor(rasterSymbolizer.NoDataColor);
for (int row = 0; row < raster.NumRows; row++)
{
for (int col = 0; col < raster.NumColumns; col++)
{
var value = getValue(row, col);
Argb argb;
if (value.Equals(noData))
{
argb = noDataColor;
}
else
{
// Usually values are not random, so check neighboring previous cells for same color
int?srcOffset = null;
if (col > 0)
{
if (value.Equals(getValue(row, col - 1)))
{
srcOffset = Offset(row, col - 1, stride);
}
}
if (srcOffset == null && row > 0)
{
if (value.Equals(getValue(row - 1, col)))
{
srcOffset = Offset(row - 1, col, stride);
}
}
if (srcOffset != null)
{
argb = new Argb(getByte((int)srcOffset + 3), getByte((int)srcOffset + 2), getByte((int)srcOffset + 1), getByte((int)srcOffset));
}
else
{
argb = GetColor(sets, value);
}
}
if (hillshade != null)
{
if (hillshade[row][col] == -1 || float.IsNaN(hillshade[row][col]))
{
argb = new Argb(argb.A, noDataColor.R, noDataColor.G, noDataColor.B);
}
else
{
var red = (int)(argb.R * hillshade[row][col]);
var green = (int)(argb.G * hillshade[row][col]);
var blue = (int)(argb.B * hillshade[row][col]);
argb = new Argb(argb.A, red, green, blue);
}
}
var offset = Offset(row, col, stride);
setByte(offset, argb.B);
setByte(offset + 1, argb.G);
setByte(offset + 2, argb.R);
setByte(offset + 3, argb.A);
}
pm.Next();
}
}