/// <summary>
/// Renders the map to an image
/// </summary>
/// <returns></returns>
public virtual Image Render()
{
// DateTime startTime = DateTime.Now; // Used when logging Rendering time of Map
if (Size.IsEmpty)
{
return(null); // nothing to render
}
if (MapRendering != null)
{
MapRendering(null);
}
if (image != null && (Size.Width != image.Width || Size.Height != image.Height)) // re-create only when it is required
{
image.Dispose();
ResourceMonitor.OnResourceDeallocated(this, image);
image = null;
}
if (image == null)
{
image = new Bitmap(Size.Width, Size.Height, PixelFormat.Format32bppPArgb);
ResourceMonitor.OnResourceAllocated(this, image);
}
if (rendering)
{
return(null);
}
rendering = true;
// TODO: draw using multiple threads
/* Action<int> renderLayer = delegate(int i)
* {
* if (Layers[i].RenderRequired)
* {
* Layers[i].Render();
* }
* };
* Parallel.For(0, Layers.Count, renderLayer);
*/
var visibleLayers = GetAllMapLayers(layers, true, true).OrderByDescending(l => l.RenderOrder).ToArray();
// draw decoration layers on top
var gridVectorLayer = GetGridLayer();
if (gridVectorLayer != null)
{
visibleLayers = visibleLayers.Concat(new[] { gridVectorLayer }).ToArray();
}
// merge all layer bitmaps
var g = Graphics.FromImage(image);
g.Clear(BackColor);
foreach (var layer in visibleLayers)
{
if (!(layer.MaxVisible >= Zoom) || !(layer.MinVisible < Zoom))
{
continue;
}
if (layer.RenderRequired || layer.Image == null)
{
layer.Render();
}
if (layer.Image == null)
{
continue;
}
if (Math.Abs(layer.Opacity - 1.0) > 0.0000001)
{
var srcWidth = layer.Image.Width;
var srcHeight = layer.Image.Height;
g.DrawImage(layer.Image, new Rectangle(0, 0, srcWidth, srcHeight), 0, 0,
srcWidth, srcHeight,
GraphicsUnit.Pixel,
CalculateOpacityImageAttributes(layer));
}
else
{
g.DrawImage(layer.Image, 0, 0);
}
if (MapLayerRendered != null)
{
MapLayerRendered(g, layer);
}
if (layer.LastRenderDuration < 100) // do not keep Bitmap if it is very fast to render
{
layer.ClearImage();
}
}
g.Transform = MapTransform;
g.PageUnit = GraphicsUnit.Pixel;
if (MapRendered != null)
{
MapRendered(g);
}
g.Dispose();
foreach (var layer in Layers)
{
ClearLayerImages(layer);
}
// don't delete, enable when optimizing performance
//double dt = (DateTime.Now - startTime).TotalMilliseconds;
//log.DebugFormat("Map rendered in {0:F0} ms, size {1} x {2} px", dt, Size.Width, Size.Height);
RenderRequired = false;
rendering = false;
return(Image);
}
//private bool rendering;
public virtual void Render()
{
/*
* if (rendering)
* {
* return; // can be dangerous, rendering from two threads?
* }
*
* rendering = true;
*
* try
* {
*/
DateTime t = DateTime.Now;
if (image != null && Map != null && (Map.Size.Width != image.Width || Map.Size.Height != image.Height))
// check if we need to re-create bitmap
{
ClearImage();
}
if (Map == null)
{
if (image != null)
{
ClearImage();
}
return;
}
if (image == null)
{
image = new Bitmap(Map.Size.Width, Map.Size.Height, PixelFormat.Format32bppPArgb);
ResourceMonitor.OnResourceAllocated(this, image);
}
if (!Visible || MaxVisible < Map.Zoom || MinVisible > Map.Zoom)
{
return;
}
Graphics graphics = Graphics.FromImage(image);
graphics.Transform = Map.MapTransform.Clone();
graphics.Clear(Color.Transparent);
graphics.PageUnit = GraphicsUnit.Pixel;
// call virtual implementation which renders layer
OnRender(graphics, Map);
if (LabelLayer != null && LabelLayer.Visible)
{
((LabelLayer)LabelLayer).OnRender(graphics, map);
}
// fire event
if (LayerRendered != null)
{
LayerRendered(this, graphics);
}
graphics.Dispose();
lastRenderDuration = (DateTime.Now - t).Milliseconds;
/*
* }
* finally
* {
* rendering = false;
* }
*/
RenderRequired = false;
}