private void DrawPoints(MapViewport map, IEnumerable <DataRow> features, Bitmap dot, Bitmap image)
{
var size = new Size(dot.Width, dot.Height);
foreach (FeatureDataRow row in features)
{
var heatValue = HeatValueComputer(row);
if (heatValue <= 0)
{
continue;
}
if (heatValue >= 1f)
{
heatValue = 1;
}
var c = row.Geometry.PointOnSurface.Coordinate;
if (CoordinateTransformation != null)
{
c = GeometryTransform.TransformCoordinate(c, CoordinateTransformation.MathTransform);
}
var posF = map.WorldToImage(c);
var pos = Point.Round(posF);
//var pos = Point.Round(PointF.Subtract(posF, halfSize));
using (var tmpDot = ApplyHeatValueToImage(dot, heatValue))
{
ImageBlender.BlendImages(image, pos.X, pos.Y, size.Width, size.Height,
tmpDot, 0, 0, BlendOperation.BlendMultiply);
}
}
}
protected void ddlProjection_SelectedIndexChanged(object sender, EventArgs e)
{
//Transform current view to new coordinate system and zoom to the transformed box
string PreviousProj = ViewState["currentProj"].ToString();
string SelectedProj = ddlProjection.SelectedValue;
//Points defining the current view
Point left = new Point(myMap.Envelope.MinX, myMap.Center.Y);
Point right = new Point(myMap.Envelope.MaxX, myMap.Center.Y);
Point center = myMap.Center;
if (PreviousProj != "Pseudo")
{
//Transform current view back to geographic coordinates
ICoordinateTransformation trans = GetTransform(PreviousProj);
left = GeometryTransform.TransformCoordinate(new Point(myMap.Envelope.MinX, myMap.Center.Y),
trans.MathTransform.Inverse());
right = GeometryTransform.TransformCoordinate(new Point(myMap.Envelope.MaxX, myMap.Center.Y),
trans.MathTransform.Inverse());
center = GeometryTransform.TransformCoordinate(myMap.Center, trans.MathTransform.Inverse());
}
//If both PreviousSRID and SelectedSRID are projected coordsys, first transform to geographic
if (SelectedProj == "Pseudo")
{
myMap.Center = center;
myMap.Zoom = Math.Abs(right.X - left.X);
}
else //Project coordinates to new projection
{
//Transform back to geographic and over to new projection
ICoordinateTransformation trans = GetTransform(SelectedProj);
left = GeometryTransform.TransformCoordinate(left, trans.MathTransform);
right = GeometryTransform.TransformCoordinate(right, trans.MathTransform);
center = GeometryTransform.TransformCoordinate(center, trans.MathTransform);
myMap.Center = center;
myMap.Zoom = Math.Abs(right.X - left.X);
var envelopeGcs = GeometryTransform.TransformBox(myMap.Envelope, trans.MathTransform.Inverse());
litEnvelopeLatLong.Text = envelopeGcs.ToString();
}
GenerateMap();
}