private void Render(SKCanvas canvas, IReadOnlyViewport viewport, IEnumerable <ILayer> layers)
{
try
{
layers = layers.ToList();
VisibleFeatureIterator.IterateLayers(viewport, layers, (v, l, s, f, o) => { RenderFeature(canvas, v, l, s, f, o); });
RemovedUnusedBitmapsFromCache();
_currentIteration++;
}
catch (Exception exception)
{
Logger.Log(LogLevel.Error, "Unexpected error in skia renderer", exception);
}
}
public MapInfo GetMapInfo(double x, double y, IReadOnlyViewport viewport, IEnumerable <ILayer> layers, int margin = 0)
{
// todo: use margin to increase the pixel area
// todo: We will need to select on style instead of layer
layers = layers
.Select(l => (l is RasterizingLayer rl) ? rl.ChildLayer : l)
.Where(l => l.IsMapInfoLayer);
var list = new List <MapInfoRecord>();
var result = new MapInfo()
{
ScreenPosition = new Point(x, y),
WorldPosition = viewport.ScreenToWorld(x, y),
Resolution = viewport.Resolution
};
try
{
var width = (int)viewport.Width;
var height = (int)viewport.Height;
var imageInfo = new SKImageInfo(width, height, SKImageInfo.PlatformColorType, SKAlphaType.Unpremul);
var intX = (int)x;
var intY = (int)y;
using (var surface = SKSurface.Create(imageInfo))
{
if (surface == null)
{
return(null);
}
surface.Canvas.ClipRect(new SKRect((float)(x - 1), (float)(y - 1), (float)(x + 1), (float)(y + 1)));
surface.Canvas.Clear(SKColors.Transparent);
var pixmap = surface.PeekPixels();
var color = pixmap.GetPixelColor(intX, intY);
VisibleFeatureIterator.IterateLayers(viewport, layers, (v, layer, style, feature, opacity) => {
surface.Canvas.Save();
// 1) Clear the entire bitmap
surface.Canvas.Clear(SKColors.Transparent);
// 2) Render the feature to the clean canvas
RenderFeature(surface.Canvas, v, layer, style, feature, opacity);
// 3) Check if the pixel has changed.
if (color != pixmap.GetPixelColor(intX, intY))
{
// 4) Add feature and style to result
list.Add(new MapInfoRecord(feature, style, layer));
}
surface.Canvas.Restore();
});
}
if (list.Count == 0)
{
return(result);
}
list.Reverse();
var itemDrawnOnTop = list.First();
result.Feature = itemDrawnOnTop.Feature;
result.Style = itemDrawnOnTop.Style;
result.Layer = itemDrawnOnTop.Layer;
result.MapInfoRecords = list;
}
catch (Exception exception)
{
Logger.Log(LogLevel.Error, "Unexpected error in skia renderer", exception);
}
return(result);
}