Adding a gradient sample to the Forms app

- Removing an unused count argument from CreateTwoPointConicalGradient
 - Bump the skia submodule to pick up the missing SK_API fix

binding/Binding/SKShader.cs

@@ -69,12 +69,12 @@ namespace SkiaSharp
 				return new SKShader (SkiaApi.sk_shader_new_sweep_gradient (ref center, colors, colorPos, colors.Length, ref localMatrix));
 		}
 
-		public static SKShader CreateTwoPointConicalGradient (SKPoint start, float startRadius, SKPoint end, float endRadius, SKColor [] colors, float [] colorPos, int count, SKShaderTileMode mode)
+		public static SKShader CreateTwoPointConicalGradient (SKPoint start, float startRadius, SKPoint end, float endRadius, SKColor [] colors, float [] colorPos, SKShaderTileMode mode)
 		{
 			return new SKShader (SkiaApi.sk_shader_new_two_point_conical_gradient (ref start, startRadius, ref end, endRadius, colors, colorPos, colors.Length, mode, IntPtr.Zero));
 		}
 		
-		public static SKShader CreateTwoPointConicalGradient (SKPoint start, float startRadius, SKPoint end, float endRadius, SKColor [] colors, float [] colorPos, int count, SKShaderTileMode mode, SKMatrix localMatrix)
+		public static SKShader CreateTwoPointConicalGradient (SKPoint start, float startRadius, SKPoint end, float endRadius, SKColor [] colors, float [] colorPos, SKShaderTileMode mode, SKMatrix localMatrix)
 		{
 			return new SKShader (SkiaApi.sk_shader_new_two_point_conical_gradient (ref start, startRadius, ref end, endRadius, colors, colorPos, colors.Length, mode, ref localMatrix));
 		}

binding/SkiaSharp.Portable/SkiaPortable.cs

@@ -373,8 +373,8 @@
 		public static SkiaSharp.SKShader CreateRadialGradient(SkiaSharp.SKPoint center, float radius, SkiaSharp.SKColor[] colors, System.Single[] colorPos, SkiaSharp.SKShaderTileMode mode, SkiaSharp.SKMatrix localMatrix) { return default(SkiaSharp.SKShader); }
 		public static SkiaSharp.SKShader CreateSweepGradient(SkiaSharp.SKPoint center, SkiaSharp.SKColor[] colors, System.Single[] colorPos) { return default(SkiaSharp.SKShader); }
 		public static SkiaSharp.SKShader CreateSweepGradient(SkiaSharp.SKPoint center, SkiaSharp.SKColor[] colors, System.Single[] colorPos, SkiaSharp.SKMatrix localMatrix) { return default(SkiaSharp.SKShader); }
-		public static SkiaSharp.SKShader CreateTwoPointConicalGradient(SkiaSharp.SKPoint start, float startRadius, SkiaSharp.SKPoint end, float endRadius, SkiaSharp.SKColor[] colors, System.Single[] colorPos, int count, SkiaSharp.SKShaderTileMode mode) { return default(SkiaSharp.SKShader); }
+		public static SkiaSharp.SKShader CreateTwoPointConicalGradient(SkiaSharp.SKPoint start, float startRadius, SkiaSharp.SKPoint end, float endRadius, SkiaSharp.SKColor[] colors, System.Single[] colorPos, SkiaSharp.SKShaderTileMode mode) { return default(SkiaSharp.SKShader); }
-		public static SkiaSharp.SKShader CreateTwoPointConicalGradient(SkiaSharp.SKPoint start, float startRadius, SkiaSharp.SKPoint end, float endRadius, SkiaSharp.SKColor[] colors, System.Single[] colorPos, int count, SkiaSharp.SKShaderTileMode mode, SkiaSharp.SKMatrix localMatrix) { return default(SkiaSharp.SKShader); }
+		public static SkiaSharp.SKShader CreateTwoPointConicalGradient(SkiaSharp.SKPoint start, float startRadius, SkiaSharp.SKPoint end, float endRadius, SkiaSharp.SKColor[] colors, System.Single[] colorPos, SkiaSharp.SKShaderTileMode mode, SkiaSharp.SKMatrix localMatrix) { return default(SkiaSharp.SKShader); }
 		public void Dispose() { }
 		protected virtual void Dispose(bool disposing) { }
 		~SKShader() { }

samples/Skia.Forms.Demo/DrawHelpers.cs

@@ -129,7 +129,47 @@ namespace Skia.Forms.Demo
 
 				canvas.DrawText ("Skia", 20.0f, 224.0f, paint);
 			}
+		}
 
+		public static void DrawGradient (SKCanvas canvas, int width, int height)
+		{
+			var ltColor = SKColors.White;
+			var dkColor = SKColors.Black;
+
+			using (var paint = new SKPaint ()) {
+				using (var shader = SKShader.CreateLinearGradient (
+					new SKPoint (0, 0),
+					new SKPoint (0, height),
+					new [] {ltColor, dkColor},
+					null,
+					SKShaderTileMode.Clamp)) {
+
+					paint.Shader = shader;
+					canvas.DrawPaint (paint);
+				}
+			}
+
+			// Center and Scale the Surface
+			var scale = (width < height ? width : height) / (240f);
+			canvas.Translate (width/2f, height/2f);
+			canvas.Scale (scale, scale);
+			canvas.Translate (-128, -128);
+
+			using (var paint = new SKPaint ()) {
+				using (var shader = SKShader.CreateTwoPointConicalGradient (
+					new SKPoint (115.2f, 102.4f), 
+					25.6f,
+					new SKPoint (102.4f, 102.4f),
+					128.0f,
+					new [] {ltColor, dkColor},
+					null,
+					SKShaderTileMode.Clamp
+				)) {
+					paint.Shader = shader;
+
+					canvas.DrawOval (new SKRect (51.2f, 51.2f, 204.8f, 204.8f), paint);
+				}
+			}
 		}
 	}
 }

samples/Skia.Forms.Demo/Skia.Forms.Demo.cs

@@ -21,7 +21,7 @@ namespace Skia.Forms.Demo
 				BarTextColor = Xamarin.Forms.Color.White,
 			};
 
-			listView.ItemsSource = new [] {"Xamagon", "Text Sample"};
+			listView.ItemsSource = new [] {"Xamagon", "Text Sample", "Gradient Sample"};
 
 			listView.ItemSelected += (sender, e) => {
 				if (e.SelectedItem == null) return;
@@ -41,6 +41,8 @@ namespace Skia.Forms.Demo
 				return DrawHelpers.DrawXamagon;
 			case "Text Sample":
 				return DrawHelpers.TextSample;
+			case "Gradient Sample":
+				return DrawHelpers.DrawGradient;
 			}
 
 			throw new NotImplementedException ();

skia

@@ -1 +1 @@
-Subproject commit 2e74eb03db87ed53376401071c32315f92d8e3b3
+Subproject commit fd370f0131e526963a77eb528819101cdc8eb871