private SharpMap.Rendering.Label CreateLabel(IGeometry feature, string text, float rotation, SharpMap.Styles.LabelStyle style, Map map, System.Drawing.Graphics g)
{
System.Drawing.SizeF size = g.MeasureString(text, style.Font);
System.Drawing.PointF position = map.WorldToImage(feature.EnvelopeInternal.Centre);
position.X = position.X - size.Width * (short)style.HorizontalAlignment * 0.5f;
position.Y = position.Y - size.Height * (short)style.VerticalAlignment * 0.5f;
if (position.X - size.Width > map.Size.Width || position.X + size.Width < 0 ||
position.Y - size.Height > map.Size.Height || position.Y + size.Height < 0)
{
return(null);
}
else
{
SharpMap.Rendering.Label lbl;
if (!style.CollisionDetection)
{
lbl = new SharpMap.Rendering.Label(text, position, rotation, this.Priority, null, style);
}
else
{
//Collision detection is enabled so we need to measure the size of the string
lbl = new SharpMap.Rendering.Label(text, position, rotation, this.Priority,
new SharpMap.Rendering.LabelBox(position.X - size.Width * 0.5f - style.CollisionBuffer.Width, position.Y + size.Height * 0.5f + style.CollisionBuffer.Height,
size.Width + 2f * style.CollisionBuffer.Width, size.Height + style.CollisionBuffer.Height * 2f), style);
}
if (feature.GetType() == typeof(ILineString))
{
ILineString line = feature as ILineString;
if (line.Length / map.PixelSize > size.Width) //Only label feature if it is long enough
{
CalculateLabelOnLinestring(line, ref lbl, map);
}
else
{
return(null);
}
}
return(lbl);
}
}
private void CalculateLabelOnLinestring(ILineString line, ref SharpMap.Rendering.Label label, Map map)
{
double dx, dy;
double tmpx, tmpy;
double angle = 0.0;
// first find the middle segment of the line
int midPoint = (line.Coordinates.Length - 1) / 2;
if (line.Coordinates.Length > 2)
{
dx = line.Coordinates[midPoint + 1].X - line.Coordinates[midPoint].X;
dy = line.Coordinates[midPoint + 1].Y - line.Coordinates[midPoint].Y;
}
else
{
midPoint = 0;
dx = line.Coordinates[1].X - line.Coordinates[0].X;
dy = line.Coordinates[1].Y - line.Coordinates[0].Y;
}
if (dy == 0)
{
label.Rotation = 0;
}
else if (dx == 0)
{
label.Rotation = 90;
}
else
{
// calculate angle of line
angle = -Math.Atan(dy / dx) + Math.PI * 0.5;
angle *= (180d / Math.PI); // convert radians to degrees
label.Rotation = (float)angle - 90; // -90 text orientation
}
tmpx = line.Coordinates[midPoint].X + (dx * 0.5);
tmpy = line.Coordinates[midPoint].Y + (dy * 0.5);
label.LabelPoint = map.WorldToImage(SharpMap.Converters.Geometries.GeometryFactory.CreateCoordinate(tmpx, tmpy));
}
private SharpMap.Rendering.Label CreateLabel(IGeometry feature,string text, float rotation, ILabelStyle style, IMap map, System.Drawing.Graphics g)
{
System.Drawing.SizeF size = g.MeasureString(text, style.Font);
System.Drawing.PointF position = map.WorldToImage(feature.EnvelopeInternal.Centre);
position.X = position.X - size.Width * (short)style.HorizontalAlignment * 0.5f;
position.Y = position.Y - size.Height * (short)style.VerticalAlignment * 0.5f;
if (position.X-size.Width > map.Size.Width || position.X+size.Width < 0 ||
position.Y-size.Height > map.Size.Height || position.Y+size.Height < 0)
return null;
else
{
SharpMap.Rendering.Label lbl;
if (!style.CollisionDetection)
lbl = new SharpMap.Rendering.Label(text, position, rotation, this.Priority, null, style);
else
{
//Collision detection is enabled so we need to measure the size of the string
lbl = new SharpMap.Rendering.Label(text, position, rotation, this.Priority,
new SharpMap.Rendering.LabelBox(position.X - size.Width * 0.5f - style.CollisionBuffer.Width, position.Y + size.Height * 0.5f + style.CollisionBuffer.Height,
size.Width + 2f * style.CollisionBuffer.Width, size.Height + style.CollisionBuffer.Height * 2f), style);
}
if (feature.GetType() == typeof(ILineString))
{
ILineString line = feature as ILineString;
if (line.Length / map.PixelSize > size.Width) //Only label feature if it is long enough
CalculateLabelOnLinestring(line, ref lbl, map);
else
return null;
}
return lbl;
}
}
public void RenderLayer(ILabelLayer layer, Map map, Graphics g)
{
if (layer.Style.Enabled &&
layer.Style.MaxVisible >= map.Zoom &&
layer.Style.MinVisible < map.Zoom)
{
if (layer.DataSource == null)
{
throw (new ApplicationException("DataSource property not set on layer '" + layer.LayerName + "'"));
}
g.TextRenderingHint = layer.TextRenderingHint;
g.SmoothingMode = layer.SmoothingMode;
SharpMap.Geometries.BoundingBox envelope = map.Envelope; //View to render
if (layer.CoordinateTransformation != null)
{
envelope = GeometryTransform.TransformBox(envelope, layer.CoordinateTransformation.MathTransform.Inverse());
}
FeatureDataSet ds = new FeatureDataSet();
layer.DataSource.Open();
layer.DataSource.ExecuteIntersectionQuery(envelope, ds);
layer.DataSource.Close();
if (ds.Tables.Count == 0)
{
//base.Render(g, map);
return;
}
FeatureDataTable features = (FeatureDataTable)ds.Tables[0];
//Initialize label collection
List <Label> labels = new List <Label>();
LabelLayer.GetLabelMethod lblDelegate = layer.LabelStringDelegate;
//List<System.Drawing.Rectangle> LabelBoxes; //Used for collision detection
//Render labels
for (int i = 0; i < features.Count; i++)
{
FeatureDataRow feature = features[i];
if (layer.CoordinateTransformation != null)
{
features[i].Geometry = GeometryTransform.TransformGeometry(features[i].Geometry, layer.CoordinateTransformation.MathTransform);
}
ILabelStyle style = null;
if (layer.Theme != null) //If thematics is enabled, lets override the style
{
style = layer.Theme.GetStyle(feature);
}
else
{
style = layer.Style;
}
float rotation = 0;
if (!String.IsNullOrEmpty(layer.RotationColumn))
{
float.TryParse(feature[layer.RotationColumn].ToString(), NumberStyles.Any, Map.numberFormat_EnUS, out rotation);
}
string text;
if (lblDelegate != null)
{
text = lblDelegate(feature);
}
else
{
text = feature[layer.LabelColumn].ToString();
}
if (text != null && text != String.Empty)
{
if (feature.Geometry is GeometryCollection)
{
if (layer.MultipartGeometryBehaviour == SharpMap.Layers.LabelLayer.MultipartGeometryBehaviourEnum.All)
{
foreach (SharpMap.Geometries.Geometry geom in (feature.Geometry as GeometryCollection))
{
SharpMap.Rendering.Label lbl = CreateLabel(layer, geom, text, rotation, style, map, g);
if (lbl != null)
{
labels.Add(lbl);
}
}
}
else if (layer.MultipartGeometryBehaviour == SharpMap.Layers.LabelLayer.MultipartGeometryBehaviourEnum.CommonCenter)
{
Label lbl = CreateLabel(layer, feature.Geometry, text, rotation, style, map, g);
if (lbl != null)
{
labels.Add(lbl);
}
}
else if (layer.MultipartGeometryBehaviour == SharpMap.Layers.LabelLayer.MultipartGeometryBehaviourEnum.First)
{
if ((feature.Geometry as GeometryCollection).Collection.Count > 0)
{
SharpMap.Rendering.Label lbl = CreateLabel(layer, (feature.Geometry as GeometryCollection).Collection[0], text, rotation, style, map, g);
if (lbl != null)
{
labels.Add(lbl);
}
}
}
else if (layer.MultipartGeometryBehaviour == SharpMap.Layers.LabelLayer.MultipartGeometryBehaviourEnum.Largest)
{
GeometryCollection coll = (feature.Geometry as GeometryCollection);
if (coll.NumGeometries > 0)
{
double largestVal = 0;
int idxOfLargest = 0;
for (int j = 0; j < coll.NumGeometries; j++)
{
SharpMap.Geometries.Geometry geom = coll.Geometry(j);
if (geom is Geometries.LineString && ((Geometries.LineString)geom).Length > largestVal)
{
largestVal = ((Geometries.LineString)geom).Length;
idxOfLargest = j;
}
if (geom is Geometries.MultiLineString && ((Geometries.MultiLineString)geom).Length > largestVal)
{
largestVal = ((Geometries.LineString)geom).Length;
idxOfLargest = j;
}
if (geom is Geometries.Polygon && ((Geometries.Polygon)geom).Area > largestVal)
{
largestVal = ((Geometries.Polygon)geom).Area;
idxOfLargest = j;
}
if (geom is Geometries.MultiPolygon && ((Geometries.MultiPolygon)geom).Area > largestVal)
{
largestVal = ((Geometries.MultiPolygon)geom).Area;
idxOfLargest = j;
}
}
SharpMap.Rendering.Label lbl = CreateLabel(layer, coll.Geometry(idxOfLargest), text, rotation, style, map, g);
if (lbl != null)
{
labels.Add(lbl);
}
}
}
}
else
{
SharpMap.Rendering.Label lbl = CreateLabel(layer, feature.Geometry, text, rotation, style, map, g);
if (lbl != null)
{
labels.Add(lbl);
}
}
}
}
if (labels.Count > 0) //We have labels to render...
{
if (layer.Style.CollisionDetection && layer.LabelFilter != null)
{
layer.LabelFilter(labels);
}
for (int i = 0; i < labels.Count; i++)
{
VectorRenderer.DrawLabel(g, labels[i].LabelPoint, labels[i].Style.Offset, labels[i].Style.Font, labels[i].Style.ForeColor, labels[i].Style.BackColor, layer.Style.Halo, labels[i].Rotation, labels[i].Text, map);
}
}
labels = null;
}
//base.Render(g, map);
}
/// <summary>
/// Renders the layer
/// </summary>
/// <param name="g">Graphics object reference</param>
/// <param name="map">Map which is rendered</param>
public override void OnRender(System.Drawing.Graphics g, Map map)
{
if (Style.Enabled && Style.MaxVisible >= map.Zoom && Style.MinVisible < map.Zoom)
{
if (DataSource == null)
{
throw (new ApplicationException("DataSource property not set on layer '" + Name + "'"));
}
g.TextRenderingHint = this.TextRenderingHint;
g.SmoothingMode = this.SmoothingMode;
IEnvelope envelope = map.Envelope; //View to render
if (CoordinateTransformation != null)
{
envelope = CoordinateSystems.Transformations.GeometryTransform.TransformBox(envelope, this.CoordinateTransformation.MathTransform.Inverse());
}
IList features = DataSource.GetFeatures(envelope);
if (features.Count == 0)
{
return;
}
//Initialize label collection
var labels = new List <Rendering.Label>();
//List<System.Drawing.Rectangle> LabelBoxes; //Used for collision detection
//Render labels
for (int i = 0; i < features.Count; i++)
{
IFeature feature = (IFeature)features[i];
if (this.CoordinateTransformation != null)
{
((IFeature)features[i]).Geometry = SharpMap.CoordinateSystems.Transformations.GeometryTransform.TransformGeometry(((IFeature)features[i]).Geometry, this.CoordinateTransformation.MathTransform);
}
SharpMap.Styles.LabelStyle style = null;
if (this.Theme != null) //If thematics is enabled, lets override the style
{
style = this.Theme.GetStyle(feature) as SharpMap.Styles.LabelStyle;
}
else
{
style = this.Style;
}
float rotation = 0;
if (!String.IsNullOrEmpty(this.RotationColumn))
{
rotation = FeatureAttributeAccessorHelper.GetAttributeValue <float>(feature, RotationColumn, 0f);
}
string text = GetText(feature);
if (text != null && text != String.Empty)
{
if (feature.Geometry is IGeometryCollection)
{
if (this.MultipartGeometryBehaviour == MultipartGeometryBehaviourEnum.All)
{
foreach (IGeometry geom in (feature.Geometry as IGeometryCollection))
{
SharpMap.Rendering.Label lbl = CreateLabel(geom, text, rotation, style, map, g);
if (lbl != null)
{
labels.Add(lbl);
}
}
}
else if (this.MultipartGeometryBehaviour == MultipartGeometryBehaviourEnum.CommonCenter)
{
SharpMap.Rendering.Label lbl = CreateLabel(feature.Geometry, text, rotation, style, map, g);
if (lbl != null)
{
labels.Add(lbl);
}
}
else if (this.MultipartGeometryBehaviour == MultipartGeometryBehaviourEnum.First)
{
if ((feature.Geometry as IGeometryCollection).Geometries.Length > 0)
{
SharpMap.Rendering.Label lbl = CreateLabel((feature.Geometry as IGeometryCollection).Geometries[0], text, rotation, style, map, g);
if (lbl != null)
{
labels.Add(lbl);
}
}
}
else if (this.MultipartGeometryBehaviour == MultipartGeometryBehaviourEnum.Largest)
{
IGeometryCollection coll = (feature.Geometry as IGeometryCollection);
if (coll.NumGeometries > 0)
{
double largestVal = 0;
int idxOfLargest = 0;
for (int j = 0; j < coll.NumGeometries; j++)
{
IGeometry geom = coll.Geometries[j];
if (geom is ILineString && ((ILineString)geom).Length > largestVal)
{
largestVal = ((ILineString)geom).Length;
idxOfLargest = j;
}
if (geom is IMultiLineString && ((IMultiLineString)geom).Length > largestVal)
{
largestVal = ((ILineString)geom).Length;
idxOfLargest = j;
}
if (geom is IPolygon && ((IPolygon)geom).Area > largestVal)
{
largestVal = ((IPolygon)geom).Area;
idxOfLargest = j;
}
if (geom is IMultiPolygon && ((IMultiPolygon)geom).Area > largestVal)
{
largestVal = ((IMultiPolygon)geom).Area;
idxOfLargest = j;
}
}
SharpMap.Rendering.Label lbl = CreateLabel(coll.Geometries[idxOfLargest], text, rotation, style, map, g);
if (lbl != null)
{
labels.Add(lbl);
}
}
}
}
else
{
SharpMap.Rendering.Label lbl = CreateLabel(feature.Geometry, text, rotation, style, map, g);
if (lbl != null)
{
labels.Add(lbl);
}
}
}
}
if (labels.Count > 0) //We have labels to render...
{
if (this.Style.CollisionDetection && this.labelFilter != null)
{
this.labelFilter(labels);
}
for (int i = 0; i < labels.Count; i++)
{
SharpMap.Rendering.VectorRenderingHelper.DrawLabel(g, labels[i].LabelPoint, labels[i].Style.Offset, labels[i].Style.Font, labels[i].Style.ForeColor, labels[i].Style.BackColor, Style.Halo, labels[i].Rotation, labels[i].Text, map);
}
}
labels = null;
}
}
