private void OnRender()
{
if (rendering && !renderingPending)
{
Dispatcher.BeginInvoke(OnRender);
return;
}
else if (rendering)
{
return;
}
if (DesignerProperties.GetIsInDesignMode(this))
{
return;
}
rendering = true;
renderingPending = false;
ContentPanel.Children.Clear();
var transform = Plotter.Viewport.Transform;
Rect output = Plotter.Viewport.Output;
Rect visible = Plotter.Viewport.Visible;
var tileInfos = GetVisibleTiles();
int minLevel = TileProvider.Level - maxLevelShift;
var lowerTiles = GetLoadedLowerTiles(tileInfos).Where(id => id.Level >= minLevel);
foreach (var tile in lowerTiles)
{
if (TileSystem.IsReady(tile))
{
BitmapImage bmp = TileSystem[tile];
Rect visibleRect = Transform(TileProvider.GetBounds(tile));
Rect screenRect = visibleRect.DataToScreen(transform);
DrawTile(bmp, screenRect, visibleRect);
}
else
{
TileSystem.BeginLoadImage(tile);
}
}
foreach (var tileInfo in tileInfos)
{
if (TileSystem.IsReady(tileInfo.Tile))
{
BitmapImage bmp = TileSystem[tileInfo.Tile];
DrawTile(bmp, tileInfo.ScreenBounds, tileInfo.VisibleBounds);
}
else
{
TileSystem.BeginLoadImage(tileInfo.Tile);
}
}
rendering = false;
}