private static Label CreateLabel(IGeometry feature, string text, float rotation, int priority, LabelStyle style, IViewport viewport,
Graphics g)
{
var gdiSize = g.MeasureString(text, style.Font.ToGdi());
var size = new Styles.Size {
Width = gdiSize.Width, Height = gdiSize.Height
};
var position = viewport.WorldToScreen(feature.GetBoundingBox().GetCentroid());
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 > viewport.Width || position.X + size.Width < 0 ||
position.Y - size.Height > viewport.Height || position.Y + size.Height < 0)
{
return(null);
}
Label label;
if (!style.CollisionDetection)
{
label = new Label(text, position, rotation, priority, null, style);
}
else
{
//Collision detection is enabled so we need to measure the size of the string
label = new Label(text, position, rotation, priority,
new 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 is LineString))
{
return(label);
}
var line = feature as LineString;
if (line.Length / viewport.Resolution > size.Width) //Only label feature if it is long enough
{
CalculateLabelOnLinestring(line, ref label, viewport);
}
else
{
return(null);
}
return(label);
}
private static Label CreateLabel(IGeometry feature, string text, float rotation, int priority, LabelStyle style, IViewport viewport,
Graphics g)
{
var gdiSize = g.MeasureString(text, style.Font.ToGdi());
var size = new Styles.Size { Width = gdiSize.Width, Height = gdiSize.Height };
var position = viewport.WorldToScreen(feature.GetBoundingBox().GetCentroid());
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 > viewport.Width || position.X + size.Width < 0 ||
position.Y - size.Height > viewport.Height || position.Y + size.Height < 0)
return null;
Label label;
if (!style.CollisionDetection)
label = new Label(text, position, rotation, priority, null, style);
else
{
//Collision detection is enabled so we need to measure the size of the string
label = new Label(text, position, rotation, priority,
new 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 is LineString)) return label;
var line = feature as LineString;
if (line.Length / viewport.Resolution > size.Width) //Only label feature if it is long enough
CalculateLabelOnLinestring(line, ref label, viewport);
else
return null;
return label;
}
