/// <summary>
/// Render is where most of the work is done. It builds a list of graphics items to be displayed and calls the S-52 rendorer to actually display them.
/// We could pass the layer, but that would mean that the S-52 code would have to decipher the layers. It seems easier just to build a list and let S-52
/// only take care of the colors, symbol, and tiling.
///
/// The goal is to create one list for each layer in the S57 record and have S52 render that layer.
///
/// S-52 will return a map of the collective layers to display. This can then either be displayed or tiled or both.
/// </summary>
/// <param name="angle"></param>
/// <returns></returns>
public static Map Render(DataSource ds)
{
// the the cursor to the little swirling circle
Cursor.Current = Cursors.WaitCursor;
S57Layer layerCollection = new S57Layer();
SharpMap.Data.FeatureDataSet fds = new FeatureDataSet();
VectorLayer vectorLayer;
Map map = new Map();
int featureCount;
//int iFeatureCount;
int fieldIndex;
string fieldValue;
SharpMap.Data.Providers.Ogr dataProvider;
//SharpMap.Layers.Layer thisLayer;
OSGeo.OGR.Feature thisFeature;
OSGeo.OGR.FeatureDefn featureDefn;
OSGeo.OGR.FieldDefn fieldDefn;
OSGeo.OGR.Layer thisLayer;
Geometry geometry;
Geometry sub_geometry;
string WKTGeometry;
DebugUtil.WriteLine("****************************************************************************");
DebugUtil.WriteLine("*** Render ***");
DebugUtil.WriteLine("****************************************************************************");
// get the datasource that is currently open
// ds = S57.DataSource;
// we are only displaying the layers that our config data says to.
int count = S57.myS57Objects.GetCount();
for (int i = 0; i < count; i++)
{
if (myS57Objects.GetDisplayFlag(i))
{
layerCollection.layerName = myS57Objects.S57ObjectsList[i].ObjectName;
}
}
for (int iLayer = 0; iLayer < ds.GetLayerCount(); iLayer++)
{
thisLayer = DataSource.GetLayerByIndex(iLayer);
DebugUtil.WriteLine("*** Layer = " + thisLayer.GetName() + "Layer Number: " + iLayer);
featureCount = thisLayer.GetFeatureCount(0); // a value of zero will get current feature count. a value of 1 will force a feature count and is slow
DebugUtil.WriteLine("*** Feature Count: " + featureCount);
// FeatureDefn pointer
featureDefn = thisLayer.GetLayerDefn();
DebugUtil.WriteLine("*** Feature Definition Name: " + featureDefn.GetName() + "Field Count: " + featureDefn.GetFieldCount());
// allocate a feature set for this layer based on featureDefn
thisFeature = new Feature(featureDefn);
DebugUtil.WriteLine("*** thisFeature Definition Reference: " + thisFeature.GetDefnRef());
// get a SharpMap dataprovider for this vector layer. this is needed before we
// can render the file
dataProvider = new SharpMap.Data.Providers.Ogr(S57.FileName, iLayer);
// make sure the dataprovider is open
if (!dataProvider.IsOpen)
{
dataProvider.Open();
}
//featureCount = thisLayer.GetFeatureCount(0);
//for (iFeatureCount = 0; iFeatureCount < featureCount; iFeatureCount++)
// reset the current feature to 0 then read all the features
thisLayer.ResetReading();
while ((thisFeature = thisLayer.GetNextFeature()) != null)
{
if (thisFeature == null)
{
MessageBox.Show("thisFeature is null and can not be processed.");
System.Environment.Exit(-1);
}
DebugUtil.WriteLine("Field count from thisFeature: " + thisFeature.GetFieldCount().ToString());
// Get the fields we want using the fieldList. This avoids process fields that have nothing to do with display.
foreach (string thisField in fieldList)
{
// check each feature for the key attributes and add them to the tree if they exist.
if ((fieldIndex = thisFeature.GetFieldIndex(thisField)) >= 0)
{
DebugUtil.WriteLine("Field = " + thisField + ". Field Index = " + fieldIndex);
fieldDefn = featureDefn.GetFieldDefn(fieldIndex);
fieldValue = DecodeField(thisFeature, fieldDefn, fieldIndex);
// valid field values are never 0 or empty
if (fieldValue != null && fieldValue != "" && fieldValue != "0")
{
// this gets the sub-geometries. not all features have sub-geometries
geometry = thisFeature.GetGeometryRef();
// only render things that actually have geometries
if (geometry != null)
{
// a bit confusing, but if it has no sub geometries, use the base geometry. mostly applies to the type POINT
if (geometry.GetGeometryCount() == 0)
{
geometry.ExportToWkt(out WKTGeometry);
vectorLayer = new VectorLayer(thisLayer.GetName(), dataProvider);
DebugUtil.WriteLine("Rendering: " + WKTGeometry);
//vectorLayer = S52.Render(ref vectorLayer, dataProvider, thisFeature, fieldDefn, WKTGeometry);
vectorLayer = S52.Render(thisLayer.GetName(), fds);
map.Layers.Add(vectorLayer);
//vectorLayer.Dispose();
}
else
{
for (int i = 0; i < geometry.GetGeometryCount(); i++)
{
sub_geometry = geometry.GetGeometryRef(i);
if (sub_geometry != null)
{
sub_geometry.ExportToWkt(out WKTGeometry);
vectorLayer = new VectorLayer(thisLayer.GetName(), dataProvider);
DebugUtil.WriteLine("Rendering: " + WKTGeometry);
//vectorLayer = S52.Render(ref vectorLayer, dataProvider, thisFeature, fieldDefn, WKTGeometry);
vectorLayer = S52.Render(thisLayer.GetName(), fds);
map.Layers.Add(vectorLayer);
//vectorLayer.Dispose();
}
}
}
}
}
}
}
}
// free the feature collection for this layer
//thisFeature.Dispose();
}
map.ZoomToExtents();
//Matrix mat = new Matrix();
//mat.RotateAt(angle, map.WorldToImage(map.Center));
//map.MapTransform = mat;
// change back to the defaul cursor
Cursor.Current = Cursors.Default;
return(map);
}
private void S57MapForm_Closing()
{
DebugUtil.Close();
}
