Changed name of TotalWeight and made it a factor, not a divider

Lehonti · Lehonti · commit fe93db36be12 · 2025-05-24T04:18:01.000+02:00
diff --git a/Pinta.Effects/Classes/ErrorDiffusionMatrix.cs b/Pinta.Effects/Classes/ErrorDiffusionMatrix.cs
@@ -75,7 +75,7 @@ public static class Predefined
 		public static ErrorDiffusionMatrix TwoRowSierra { get; } = new ErrorDiffusionMatrix (DefaultMatrixArrays.TwoRowSierra, 2);
 		public static ErrorDiffusionMatrix SierraLite { get; } = new ErrorDiffusionMatrix (DefaultMatrixArrays.SierraLite, 1);
 		public static ErrorDiffusionMatrix Burkes { get; } = new ErrorDiffusionMatrix (DefaultMatrixArrays.Burkes, 2);
-		public static ErrorDiffusionMatrix Atkinson { get; } = new ErrorDiffusionMatrix (DefaultMatrixArrays.Atkinson, 1, 8);
+		public static ErrorDiffusionMatrix Atkinson { get; } = new ErrorDiffusionMatrix (DefaultMatrixArrays.Atkinson, 1, 0.25);
 		public static ErrorDiffusionMatrix Stucki { get; } = new ErrorDiffusionMatrix (DefaultMatrixArrays.Stucki, 2);
 		public static ErrorDiffusionMatrix JarvisJudiceNinke { get; } = new ErrorDiffusionMatrix (DefaultMatrixArrays.JarvisJudiceNinke, 2);
 		public static ErrorDiffusionMatrix FloydSteinberg { get; } = new ErrorDiffusionMatrix (DefaultMatrixArrays.FloydSteinberg, 1);
@@ -137,12 +137,12 @@ private static class DefaultMatrixArrays
 	private readonly int[,] array_2_d;
 	public int Columns { get; }
 	public int Rows { get; }
-	public int TotalWeight { get; }
+	public double WeightReductionFactor { get; }
 	public int ColumnsToLeft { get; }
 	public int ColumnsToRight { get; }
 	public int RowsBelow { get; }
 	public int this[int row, int column] => array_2_d[row, column];
-	public ErrorDiffusionMatrix (int[,] array2D, int pixelColumn, int? totalWeight = null)
+	public ErrorDiffusionMatrix (int[,] array2D, int pixelColumn, double? weightReductionFactor = null)
 	{
 		var clone = (int[,]) array2D.Clone ();
 		var rows = clone.GetLength (0);
@@ -157,7 +157,7 @@ public ErrorDiffusionMatrix (int[,] array2D, int pixelColumn, int? totalWeight =
 		if (flattened.Take (pixelColumn).Any (w => w != 0)) throw new ArgumentException ("Pixels previous to target cannot have nonzero weights");
 		ColumnsToLeft = pixelColumn;
 		ColumnsToRight = columns - 1 - pixelColumn;
-		TotalWeight = totalWeight ?? flattened.Sum ();
+		WeightReductionFactor = weightReductionFactor ?? (1.0 / flattened.Sum ());
 		Columns = columns;
 		Rows = rows;
 		RowsBelow = rows - 1;
diff --git a/Pinta.Effects/Effects/DitheringEffect.cs b/Pinta.Effects/Effects/DitheringEffect.cs
@@ -90,7 +90,7 @@ protected override void Render (ImageSurface src, ImageSurface dest, RectangleI
 
 					int idx = (thisItem.Y * settings.sourceWidth) + thisItem.X;
 
-					double factor = ((double) weight) / settings.diffusionMatrix.TotalWeight;
+					double factor = weight * settings.diffusionMatrix.WeightReductionFactor;
 
 					dst_data[idx] = AddError (dst_data[idx], factor, errorRed, errorGreen, errorBlue);
 				}

Original file line number	Diff line number	Diff line change
`@@ -90,7 +90,7 @@ protected override void Render (ImageSurface src, ImageSurface dest, RectangleI`
`90`	`90`
`91`	`91`	`int idx = (thisItem.Y * settings.sourceWidth) + thisItem.X;`
`92`	`92`
`93`		`- double factor = ((double) weight) / settings.diffusionMatrix.TotalWeight;`
	`93`	`+ double factor = weight * settings.diffusionMatrix.WeightReductionFactor;`
`94`	`94`
`95`	`95`	`dst_data[idx] = AddError (dst_data[idx], factor, errorRed, errorGreen, errorBlue);`
`96`	`96`	`}`