Fixing the bitmap resize/scale methods

- consistency
    - `Resize` is for methods that create new objects
    - `ScalePixels` is for mthods that COPY pixels INTO a provided object
 - uniformity
    - all 3 imageing types have pixel scaling capabilities
 - improved obsolete desriptions
 - added new methods instead of just obsoleting
 - added more tests

binding/Binding/SKBitmap.cs

@@ -744,12 +744,22 @@ namespace SkiaSharp
 			return SkiaApi.sk_bitmap_peek_pixels (Handle, pixmap.Handle);
 		}
 
-		[Obsolete]
-		public SKBitmap Resize (SKImageInfo info, SKBitmapResizeMethod method)
+		[Obsolete ("Use Resize(SKImageInfo, SKFilterQuality) instead.")]
+		public SKBitmap Resize (SKImageInfo info, SKBitmapResizeMethod method) =>
+			Resize (info, method.ToFilterQuality ());
+
+		[Obsolete ("Use ScalePixels(SKBitmap, SKFilterQuality) instead.")]
+		public bool Resize (SKBitmap dst, SKBitmapResizeMethod method) =>
+			ScalePixels (dst, method.ToFilterQuality ());
+
+		[Obsolete ("Use ScalePixels(SKBitmap, SKFilterQuality) instead.")]
+		public static bool Resize (SKBitmap dst, SKBitmap src, SKBitmapResizeMethod method) =>
+			src.ScalePixels (dst, method.ToFilterQuality ());
+
+		public SKBitmap Resize (SKImageInfo info, SKFilterQuality quality)
 		{
 			var dst = new SKBitmap (info);
-			var result = Resize (dst, this, method);
-			if (result) {
+			if (ScalePixels (dst, quality)) {
 				return dst;
 			} else {
 				dst.Dispose ();
@@ -757,18 +767,25 @@ namespace SkiaSharp
 			}
 		}
 
-		[Obsolete]
-		public bool Resize (SKBitmap dst, SKBitmapResizeMethod method)
+		public bool ScalePixels (SKBitmap destination, SKFilterQuality quality)
 		{
-			return Resize (dst, this, method);
+			if (destination == null) {
+				throw new ArgumentNullException (nameof (destination));
+			}
+
+			using (var dstPix = destination.PeekPixels ()) {
+				return ScalePixels (dstPix, quality);
+			}
 		}
 
-		[Obsolete]
-		public static bool Resize (SKBitmap dst, SKBitmap src, SKBitmapResizeMethod method)
+		public bool ScalePixels (SKPixmap destination, SKFilterQuality quality)
 		{
-			using (var srcPix = src.PeekPixels ())
-			using (var dstPix = dst.PeekPixels ()) {
-				return SKPixmap.Resize (dstPix, srcPix, method);// && dst.InstallPixels (dstPix); 
+			if (destination == null) {
+				throw new ArgumentNullException (nameof (destination));
+			}
+
+			using (var srcPix = PeekPixels ()) {
+				return srcPix.ScalePixels (destination, quality);
 			}
 		}
 

tests/Tests/SKBitmapTest.cs

@@ -267,7 +267,7 @@ namespace SkiaSharp.Tests
 
 		[SkippableFact]
 		[Obsolete]
-		public void BitmapResizes()
+		public void BitmapResizesObsolete()
 		{
 			var srcInfo = new SKImageInfo(200, 200);
 			var dstInfo = new SKImageInfo(100, 100);
@@ -290,6 +290,55 @@ namespace SkiaSharp.Tests
 			Assert.Equal(SKColors.Blue, dstBmp.GetPixel(75, 75));
 		}
 
+		[SkippableFact]
+		public void BitmapResizes()
+		{
+			var srcInfo = new SKImageInfo(200, 200);
+			var dstInfo = new SKImageInfo(100, 100);
+
+			var srcBmp = new SKBitmap(srcInfo);
+
+			using (var canvas = new SKCanvas(srcBmp))
+			using (var paint = new SKPaint { Color = SKColors.Green }) {
+				canvas.Clear(SKColors.Blue);
+				canvas.DrawRect(new SKRect(0, 0, 100, 200), paint);
+			}
+
+			Assert.Equal(SKColors.Green, srcBmp.GetPixel(75, 75));
+			Assert.Equal(SKColors.Blue, srcBmp.GetPixel(175, 175));
+
+			var dstBmp = srcBmp.Resize(dstInfo, SKFilterQuality.High);
+			Assert.NotNull(dstBmp);
+
+			Assert.Equal(SKColors.Green, dstBmp.GetPixel(25, 25));
+			Assert.Equal(SKColors.Blue, dstBmp.GetPixel(75, 75));
+		}
+
+		[SkippableFact]
+		public void CanScalePixels()
+		{
+			var srcInfo = new SKImageInfo(200, 200);
+			var dstInfo = new SKImageInfo(100, 100);
+
+			var srcBmp = new SKBitmap(srcInfo);
+			var dstBmp = new SKBitmap(dstInfo);
+
+			using (var canvas = new SKCanvas(srcBmp))
+			using (var paint = new SKPaint { Color = SKColors.Green })
+			{
+				canvas.Clear(SKColors.Blue);
+				canvas.DrawRect(new SKRect(0, 0, 100, 200), paint);
+			}
+
+			Assert.Equal(SKColors.Green, srcBmp.GetPixel(75, 75));
+			Assert.Equal(SKColors.Blue, srcBmp.GetPixel(175, 175));
+
+			Assert.True(srcBmp.ScalePixels(dstBmp, SKFilterQuality.High));
+
+			Assert.Equal(SKColors.Green, dstBmp.GetPixel(25, 25));
+			Assert.Equal(SKColors.Blue, dstBmp.GetPixel(75, 75));
+		}
+
 		[SkippableFact]
 		public void AlphaMaskIsApplied()
 		{
@@ -339,6 +388,7 @@ namespace SkiaSharp.Tests
 		}
 
 		[SkippableFact(Skip = "This test takes a long time (~3mins), so ignore this most of the time.")]
+		[Obsolete]
 		public static void ImageScalingMultipleThreadsTest()
 		{
 			const int numThreads = 100;
@@ -365,6 +415,7 @@ namespace SkiaSharp.Tests
 			Console.WriteLine($"Test completed for {numThreads} tasks, {numIterationsPerThread} each.");
 		}
 
+		[Obsolete]
 		private static byte[] ComputeThumbnail(string fileName)
 		{
 			using (var ms = new MemoryStream())

tests/Tests/SKImageTest.cs

@@ -263,6 +263,34 @@ namespace SkiaSharp.Tests
 			}
 		}
 
+		[SkippableFact]
+		public void CanScalePixels()
+		{
+			var srcInfo = new SKImageInfo(200, 200);
+			var dstInfo = new SKImageInfo(100, 100);
+
+			var srcSurface = SKSurface.Create(srcInfo);
+			var dstBmp = new SKBitmap(dstInfo);
+
+			using (var paint = new SKPaint { Color = SKColors.Green })
+			{
+				srcSurface.Canvas.Clear(SKColors.Blue);
+				srcSurface.Canvas.DrawRect(new SKRect(0, 0, 100, 200), paint);
+			}
+
+			var srcImage = srcSurface.Snapshot();
+			var srcPix = srcImage.PeekPixels();
+			var dstPix = dstBmp.PeekPixels();
+
+			Assert.Equal(SKColors.Green, srcPix.GetPixelColor(75, 75));
+			Assert.Equal(SKColors.Blue, srcPix.GetPixelColor(175, 175));
+
+			Assert.True(srcImage.ScalePixels(dstPix, SKFilterQuality.High));
+
+			Assert.Equal(SKColors.Green, dstBmp.GetPixel(25, 25));
+			Assert.Equal(SKColors.Blue, dstBmp.GetPixel(75, 75));
+		}
+
 		[Obsolete]
 		[SkippableFact]
 		public void EncodeWithSimpleSerializer()

tests/Tests/SKPixmapTest.cs

@@ -6,6 +6,34 @@ namespace SkiaSharp.Tests
 {
 	public class SKPixmapTest : SKTest
 	{
+		[SkippableFact]
+		public void CanScalePixels()
+		{
+			var srcInfo = new SKImageInfo(200, 200);
+			var dstInfo = new SKImageInfo(100, 100);
+
+			var srcBmp = new SKBitmap(srcInfo);
+			var dstBmp = new SKBitmap(dstInfo);
+
+			using (var canvas = new SKCanvas(srcBmp))
+			using (var paint = new SKPaint { Color = SKColors.Green })
+			{
+				canvas.Clear(SKColors.Blue);
+				canvas.DrawRect(new SKRect(0, 0, 100, 200), paint);
+			}
+
+			Assert.Equal(SKColors.Green, srcBmp.GetPixel(75, 75));
+			Assert.Equal(SKColors.Blue, srcBmp.GetPixel(175, 175));
+
+			var srcPix = srcBmp.PeekPixels();
+			var dstPix = dstBmp.PeekPixels();
+
+			Assert.True(srcPix.ScalePixels(dstPix, SKFilterQuality.High));
+
+			Assert.Equal(SKColors.Green, dstBmp.GetPixel(25, 25));
+			Assert.Equal(SKColors.Blue, dstBmp.GetPixel(75, 75));
+		}
+
 		[SkippableFact]
 		public void ReadPixelSucceeds()
 		{