/// <summary>
/// Draws grid lines to match boundaries for 10 character PlusCodes.
/// </summary>
/// <param name="totalArea">the GeoArea to draw lines in</param>
/// <returns>the byte array for the maptile png file</returns>
public byte[] DrawCell10GridLines(GeoArea totalArea)
{
int imageSizeX = IMapTiles.SlippyTileSizeSquare;
int imageSizeY = IMapTiles.SlippyTileSizeSquare;
SKBitmap bitmap = new SKBitmap(imageSizeX, imageSizeY, SKColorType.Rgba8888, SKAlphaType.Premul);
SKCanvas canvas = new SKCanvas(bitmap);
var bgColor = new SKColor();
SKColor.TryParse("00000000", out bgColor);
canvas.Clear(bgColor);
canvas.Scale(1, -1, imageSizeX / 2, imageSizeY / 2);
SKPaint paint = new SKPaint();
SKColor color = new SKColor();
SKColor.TryParse("#00CCFF", out color);
paint.Color = color;
paint.Style = SKPaintStyle.Stroke;
paint.StrokeWidth = 1;
paint.IsAntialias = true;
double degreesPerPixelX = totalArea.LongitudeWidth / imageSizeX;
double degreesPerPixelY = totalArea.LatitudeHeight / imageSizeY;
//This is hardcoded to Cell 8 spaced gridlines.
var imageLeft = totalArea.WestLongitude;
var spaceToFirstLineLeft = (imageLeft % resolutionCell10);
var imageBottom = totalArea.SouthLatitude;
var spaceToFirstLineBottom = (imageBottom % resolutionCell10);
double lonLineTrackerDegrees = imageLeft - spaceToFirstLineLeft; //This is degree coords
while (lonLineTrackerDegrees <= totalArea.EastLongitude + resolutionCell10) //This means we should always draw at least 2 lines, even if they're off-canvas.
{
var geoLine = new LineString(new Coordinate[] { new Coordinate(lonLineTrackerDegrees, 90), new Coordinate(lonLineTrackerDegrees, -90) });
var points = PolygonToSKPoints(geoLine, totalArea, degreesPerPixelX, degreesPerPixelY);
canvas.DrawLine(points[0], points[1], paint);
lonLineTrackerDegrees += resolutionCell10;
}
double latLineTrackerDegrees = imageBottom - spaceToFirstLineBottom; //This is degree coords
while (latLineTrackerDegrees <= totalArea.NorthLatitude + resolutionCell10) //This means we should always draw at least 2 lines, even if they're off-canvas.
{
var geoLine = new LineString(new Coordinate[] { new Coordinate(180, latLineTrackerDegrees), new Coordinate(-180, latLineTrackerDegrees) });
var points = PolygonToSKPoints(geoLine, totalArea, degreesPerPixelX, degreesPerPixelY);
canvas.DrawLine(points[0], points[1], paint);
latLineTrackerDegrees += resolutionCell10;
}
var ms = new MemoryStream();
var skms = new SkiaSharp.SKManagedWStream(ms);
bitmap.Encode(skms, SkiaSharp.SKEncodedImageFormat.Png, 100);
var results = ms.ToArray();
skms.Dispose(); ms.Close(); ms.Dispose();
return(results);
}
/// <summary>
/// Combines 2 images into one, given the shared ImageStats for both supplied images.
/// </summary>
/// <param name="info">the ImageStats object used to generate both bottom and top tiles.</param>
/// <param name="bottomTile">the tile to use as the base of the image. Expected to be opaque.</param>
/// <param name="topTile">The tile to layer on top. Expected to be at least partly transparent or translucent.</param>
/// <returns></returns>
public byte[] LayerTiles(ImageStats info, byte[] bottomTile, byte[] topTile)
{
SkiaSharp.SKBitmap bitmap = new SkiaSharp.SKBitmap(info.imageSizeX, info.imageSizeY, SkiaSharp.SKColorType.Rgba8888, SkiaSharp.SKAlphaType.Premul);
SkiaSharp.SKCanvas canvas = new SkiaSharp.SKCanvas(bitmap);
SkiaSharp.SKPaint paint = new SkiaSharp.SKPaint();
canvas.Scale(1, 1, info.imageSizeX / 2, info.imageSizeY / 2);
paint.IsAntialias = true;
var baseBmp = SkiaSharp.SKBitmap.Decode(bottomTile);
var topBmp = SkiaSharp.SKBitmap.Decode(topTile);
canvas.DrawBitmap(baseBmp, 0, 0);
canvas.DrawBitmap(topBmp, 0, 0);
var ms = new MemoryStream();
var skms = new SkiaSharp.SKManagedWStream(ms);
bitmap.Encode(skms, SkiaSharp.SKEncodedImageFormat.Png, 100);
var output = ms.ToArray();
skms.Dispose(); ms.Close(); ms.Dispose();
return(output);
}