private async Task <byte[]> CreateMapImageAsync(
int width,
int height,
Models.Bounds boundingBox,
string mediaType,
bool isTransparent,
uint backgroundColor,
IList <string> layerNames)
{
var imageInfo = new SKImageInfo(
width: width,
height: height,
colorType: SKColorType.Rgba8888,
alphaType: SKAlphaType.Premul);
using var surface = SKSurface.Create(imageInfo);
using var canvas = surface.Canvas;
canvas.Clear(new SKColor(backgroundColor));
foreach (var layerName in layerNames)
{
if (this.tileSourceFabric.Contains(layerName))
{
await WmsHelper.DrawLayerAsync( // TODO: ? pass required format to avoid conversions
this.tileSourceFabric.Get(layerName),
width,
height,
boundingBox,
canvas,
isTransparent,
backgroundColor);
}
}
using SKImage image = surface.Snapshot();
if (String.Compare(mediaType, MediaTypeNames.Image.Tiff, StringComparison.OrdinalIgnoreCase) == 0)
{
using var bitmap = SKBitmap.FromImage(image);
// TODO: improve performance of pixels processing, maybe using unsafe/pointers
var pixels = bitmap.Pixels.SelectMany(p => new byte[] { p.Red, p.Green, p.Blue, p.Alpha }).ToArray();
var tiff = ImageHelper.CreateTiffImage(pixels, image.Width, image.Height);
return(tiff);
}
else
{
var imageFormat = U.ImageHelper.SKEncodedImageFormatFromMediaType(mediaType);
using SKData data = image.Encode(imageFormat, 90); // TODO: ? quality parameter
return(data.ToArray());
}
}
