It is now possible to choose the edge behavior for tile reflection (#…

…1141)

* Tile effect now using Cairo extensions to obtain sample

* Added other kinds of edges to `TileEffect`

* Moved `EdgeBehavior` `enum` out of `Warp`

* Added tests for different edge behaviors

* Moved extension to CairoExtensions

* No bilinear sampling for positions inside surface

Pinta.Core/Extensions/CairoExtensions.cs

@@ -935,6 +935,49 @@ public static ColorBgra GetBilinearSampleWrapped (
 			}
 		}
 
+		public static ColorBgra GetBilinearSampleReflected (
+			this ImageSurface src,
+			ReadOnlySpan<ColorBgra> src_data,
+			int srcWidth,
+			int srcHeight,
+			float x,
+			float y
+		) => src.GetBilinearSampleClamped (
+			src_data,
+			srcWidth,
+			srcHeight,
+			ReflectCoord (x, srcWidth),
+			ReflectCoord (y, srcHeight));
+
+		public static ColorBgra GetBilinearSampleReflected (
+			this ImageSurface src,
+			float x,
+			float y
+		) => GetBilinearSampleClamped (
+			src,
+			ReflectCoord (x, src.Width),
+			ReflectCoord (y, src.Height));
+
+		private static float ReflectCoord (float value, int max)
+		{
+			bool reflection = false;
+
+			while (value < 0) {
+				value += max;
+				reflection = !reflection;
+			}
+
+			while (value > max) {
+				value -= max;
+				reflection = !reflection;
+			}
+
+			if (reflection)
+				value = max - value;
+
+			return value;
+		}
+
 		public static void TranslatePointsInPlace (this Span<PointI> points, PointI delta)
 		{
 			for (int i = 0; i < points.Length; ++i)

Pinta.Effects/Algorithms/Warp.cs

@@ -11,8 +11,8 @@
 using System.Collections.Generic;
 using System.Drawing;
 using Cairo;
+using GLib.Internal;
 using Pinta.Core;
-using Pinta.Gui.Widgets;
 
 namespace Pinta.Effects;
 
@@ -25,30 +25,6 @@ public interface IEffectData
 		EdgeBehavior EdgeBehavior { get; }
 	}
 
-	public enum EdgeBehavior
-	{
-		[Caption ("Clamp")]
-		Clamp,
-
-		[Caption ("Wrap")]
-		Wrap,
-
-		[Caption ("Reflect")]
-		Reflect,
-
-		[Caption ("Primary")]
-		Primary,
-
-		[Caption ("Secondary")]
-		Secondary,
-
-		[Caption ("Transparent")]
-		Transparent,
-
-		[Caption ("Original")]
-		Original,
-	}
-
 	public readonly record struct TransformData (double X, double Y);
 
 	public delegate TransformData TransformInverter (
@@ -67,26 +43,6 @@ public sealed record Settings (
 	private static bool IsOnSurface (this ImageSurface src, float u, float v)
 		=> (u >= 0 && u <= (src.Width - 1) && v >= 0 && v <= (src.Height - 1));
 
-	private static float ReflectCoord (float value, int max)
-	{
-		bool reflection = false;
-
-		while (value < 0) {
-			value += max;
-			reflection = !reflection;
-		}
-
-		while (value > max) {
-			value -= max;
-			reflection = !reflection;
-		}
-
-		if (reflection)
-			value = max - value;
-
-		return value;
-	}
-
 	public static Settings CreateSettings (
 		IEffectData warpData,
 		RectangleI selectionBounds,
@@ -155,7 +111,7 @@ private static ColorBgra GetSample (
 		return settings.edgeBehavior switch {
 			EdgeBehavior.Clamp => src.GetBilinearSampleClamped (preliminarySample.X, preliminarySample.Y),
 			EdgeBehavior.Wrap => src.GetBilinearSampleWrapped (preliminarySample.X, preliminarySample.Y),
-			EdgeBehavior.Reflect => src.GetBilinearSampleClamped (ReflectCoord (preliminarySample.X, src.Width), ReflectCoord (preliminarySample.Y, src.Height)),
+			EdgeBehavior.Reflect => src.GetBilinearSampleReflected (preliminarySample.X, preliminarySample.Y),
 			EdgeBehavior.Primary => settings.primaryColor,
 			EdgeBehavior.Secondary => settings.secondaryColor,
 			EdgeBehavior.Transparent => ColorBgra.Transparent,

Pinta.Effects/Classes/EdgeBehavior.cs

@@ -0,0 +1,27 @@
+using Pinta.Gui.Widgets;
+
+namespace Pinta.Effects;
+
+public enum EdgeBehavior
+{
+	[Caption ("Clamp")]
+	Clamp,
+
+	[Caption ("Wrap")]
+	Wrap,
+
+	[Caption ("Reflect")]
+	Reflect,
+
+	[Caption ("Primary")]
+	Primary,
+
+	[Caption ("Secondary")]
+	Secondary,
+
+	[Caption ("Transparent")]
+	Transparent,
+
+	[Caption ("Original")]
+	Original,
+}

Pinta.Effects/Effects/DentsEffect.cs

@@ -159,5 +159,5 @@ public sealed class DentsData : EffectData, Warp.IEffectData
 	[Caption ("Center Offset")]
 	public CenterOffset<double> CenterOffset { get; set; }
 
-	public Warp.EdgeBehavior EdgeBehavior { get; set; } = Warp.EdgeBehavior.Wrap;
+	public EdgeBehavior EdgeBehavior { get; set; } = EdgeBehavior.Wrap;
 }

Pinta.Effects/Effects/PolarInversionEffect.cs

@@ -101,5 +101,5 @@ public sealed class PolarInversionData : EffectData, Warp.IEffectData
 	[Caption ("Center Offset")]
 	public CenterOffset<double> CenterOffset { get; set; }
 
-	public Warp.EdgeBehavior EdgeBehavior { get; set; } = Warp.EdgeBehavior.Reflect;
+	public EdgeBehavior EdgeBehavior { get; set; } = EdgeBehavior.Reflect;
 }

Pinta.Effects/Effects/TileEffect.cs

@@ -38,9 +38,11 @@ public TileData Data
 		=> (TileData) EffectData!;
 
 	private readonly IChromeService chrome;
+	private readonly IPaletteService palette;
 	public TileEffect (IServiceProvider services)
 	{
 		chrome = services.GetService<IChromeService> ();
+		palette = services.GetService<IPaletteService> ();
 		EffectData = new TileData ();
 	}
 
@@ -55,6 +57,7 @@ private sealed record TileSettings (
 		float cos,
 		float tileScale,
 		float adjustedIntensity,
+		EdgeBehavior edgeBehavior,
 		IReadOnlyList<PointD> antiAliasPoints,
 		Func<float, float> waveFunction);
 
@@ -76,6 +79,7 @@ private TileSettings CreateSettings (ImageSurface source)
 			cos: cos,
 			tileScale: (float) Math.PI / tileSize,
 			adjustedIntensity: preliminaryIntensity * preliminaryIntensity / 10 * Math.Sign (preliminaryIntensity),
+			edgeBehavior: Data.EdgeBehavior,
 			antiAliasPoints: InitializeAntiAliasPoints (ANTI_ALIAS_LEVEL, antiAliasSample, sin, cos),
 			waveFunction: GetWaveFunction (Data.WaveType)
 		);
@@ -130,14 +134,16 @@ protected override void Render (
 	}
 
 	// Algorithm Code Ported From PDN
-	private static ColorBgra GetFinalPixelColor (
+	private ColorBgra GetFinalPixelColor (
 		ImageSurface source,
 		TileSettings settings,
 		ReadOnlySpan<ColorBgra> sourceData,
 		PixelOffset pixel)
 	{
 		Span<ColorBgra> samples = stackalloc ColorBgra[settings.antiAliasPoints.Count];
 
+		ColorBgra original = sourceData[pixel.memoryOffset];
+
 		float i = pixel.coordinates.X - settings.halfWidth;
 		float j = pixel.coordinates.Y - settings.halfHeight;
 
@@ -166,34 +172,53 @@ private static ColorBgra GetFinalPixelColor (
 			float finalV = settings.sin * transformedS + settings.cos * transformedT;
 
 			// Translate back to image coordinates
-			int unwrappedSampleX = (int) (settings.halfWidth + finalU);
-			int unwrappedSampleY = (int) (settings.halfHeight + finalV);
-
-			// Ensure coordinates wrap around the image dimensions
-
-			int wrappedSampleX = (unwrappedSampleX + settings.size.Width) % settings.size.Width;
-			int wrappedSampleY = (unwrappedSampleY + settings.size.Height) % settings.size.Height;
-
-			int adjustedSampleX =
-				(wrappedSampleX < 0)
-				? (wrappedSampleX + settings.size.Width) % settings.size.Width
-				: wrappedSampleX;
-			int adjustedSampleY =
-				(wrappedSampleY < 0)
-				? (wrappedSampleY + settings.size.Height) % settings.size.Height
-				: wrappedSampleY;
-
-			PointI samplePosition = new (adjustedSampleX, adjustedSampleY);
+			float preliminaryX = settings.halfWidth + finalU;
+			float preliminaryY = settings.halfHeight + finalV;
 
-			samples[p] = source.GetColorBgra (
+			samples[p] = GetSample (
+				settings,
+				source,
 				sourceData,
-				settings.size.Width,
-				samplePosition);
+				original,
+				preliminaryX,
+				preliminaryY);
 		}
 
 		return ColorBgra.Blend (samples);
 	}
 
+	private ColorBgra GetSample (
+		TileSettings settings,
+		ImageSurface source,
+		ReadOnlySpan<ColorBgra> sourceData,
+		ColorBgra original,
+		float preliminaryX,
+		float preliminaryY)
+	{
+		if (IsOnSurface (settings, preliminaryX, preliminaryY)) {
+			int floorX = (int) preliminaryX;
+			int floorY = (int) preliminaryY;
+			int rowOffset = floorY * settings.size.Width;
+			int columnOffset = floorX;
+			int pixelOffset = rowOffset + columnOffset;
+			return sourceData[pixelOffset];
+		}
+
+		return settings.edgeBehavior switch {
+			EdgeBehavior.Clamp => source.GetBilinearSampleClamped (sourceData, settings.size.Width, settings.size.Height, preliminaryX, preliminaryY),
+			EdgeBehavior.Wrap => source.GetBilinearSampleWrapped (sourceData, settings.size.Width, settings.size.Height, preliminaryX, preliminaryY),
+			EdgeBehavior.Reflect => source.GetBilinearSampleReflected (sourceData, settings.size.Width, settings.size.Height, preliminaryX, preliminaryY),
+			EdgeBehavior.Primary => palette.PrimaryColor.ToColorBgra (),
+			EdgeBehavior.Secondary => palette.SecondaryColor.ToColorBgra (),
+			EdgeBehavior.Transparent => ColorBgra.Transparent,
+			EdgeBehavior.Original => original,
+			_ => throw new ArgumentException ($"{nameof (settings.edgeBehavior)} is out of range", nameof (settings)),
+		};
+	}
+
+	private static bool IsOnSurface (TileSettings settings, float u, float v)
+		=> (u >= 0 && u <= (settings.size.Width - 1) && v >= 0 && v <= (settings.size.Height - 1));
+
 	public sealed class TileData : EffectData
 	{
 		[Caption ("Rotation"), MinimumValue (-45), MaximumValue (45)]
@@ -207,6 +232,9 @@ public sealed class TileData : EffectData
 
 		[Caption ("Tile Type")]
 		public TileType WaveType { get; set; } = TileType.SharpEdges;
+
+		[Caption ("Edge Behavior")]
+		public EdgeBehavior EdgeBehavior { get; set; } = EdgeBehavior.Wrap;
 	}
 }
 

tests/Pinta.Effects.Tests/EffectsTest.cs

@@ -121,7 +121,7 @@ public void Dents7 ()
 	{
 		DentsEffect effect = new (Utilities.CreateMockServices ());
 		effect.Data.CenterOffset = new CenterOffset<double> (0, 0);
-		effect.Data.EdgeBehavior = Warp.EdgeBehavior.Clamp;
+		effect.Data.EdgeBehavior = EdgeBehavior.Clamp;
 		Utilities.TestEffect (effect, "dents7.png");
 	}
 
@@ -512,6 +512,54 @@ public void Tile4 ()
 		Utilities.TestEffect (effect, "tile4.png");
 	}
 
+	[Test]
+	public void Tile5 ()
+	{
+		TileEffect effect = new (Utilities.CreateMockServices ());
+		effect.Data.EdgeBehavior = EdgeBehavior.Clamp;
+		Utilities.TestEffect (effect, "tile5.png");
+	}
+
+	[Test]
+	public void Tile6 ()
+	{
+		TileEffect effect = new (Utilities.CreateMockServices ());
+		effect.Data.EdgeBehavior = EdgeBehavior.Reflect;
+		Utilities.TestEffect (effect, "tile6.png");
+	}
+
+	[Test]
+	public void Tile7 ()
+	{
+		TileEffect effect = new (Utilities.CreateMockServices ());
+		effect.Data.EdgeBehavior = EdgeBehavior.Primary;
+		Utilities.TestEffect (effect, "tile7.png");
+	}
+
+	[Test]
+	public void Tile8 ()
+	{
+		TileEffect effect = new (Utilities.CreateMockServices ());
+		effect.Data.EdgeBehavior = EdgeBehavior.Secondary;
+		Utilities.TestEffect (effect, "tile8.png");
+	}
+
+	[Test]
+	public void Tile9 ()
+	{
+		TileEffect effect = new (Utilities.CreateMockServices ());
+		effect.Data.EdgeBehavior = EdgeBehavior.Transparent;
+		Utilities.TestEffect (effect, "tile9.png");
+	}
+
+	[Test]
+	public void Tile10 ()
+	{
+		TileEffect effect = new (Utilities.CreateMockServices ());
+		effect.Data.EdgeBehavior = EdgeBehavior.Original;
+		Utilities.TestEffect (effect, "tile10.png");
+	}
+
 	[Test]
 	public void Twist1 ()
 	{