Fixed pixel snapping of lines in folding margin.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@5218 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/CaretLayer.cs

@@ -79,7 +79,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 				                  caretRectangle.Y - textView.VerticalOffset,
 				                  caretRectangle.Width,
 				                  caretRectangle.Height);
-				drawingContext.DrawRectangle(caretBrush, null, PixelSnapHelpers.ToPixels(r));
+				drawingContext.DrawRectangle(caretBrush, null, PixelSnapHelpers.PixelAlign(r));
 			}
 		}
 	}

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Folding/FoldingMargin.cs

@@ -37,7 +37,8 @@ namespace ICSharpCode.AvalonEdit.Folding
 			foreach (FoldingMarginMarker m in markers) {
 				m.Measure(availableSize);
 			}
-			return new Size(SizeFactor * (double)GetValue(TextBlock.FontSizeProperty), 0);
+			double width = SizeFactor * (double)GetValue(TextBlock.FontSizeProperty);
+			return new Size(PixelSnapHelpers.RoundToOdd(width), 0);
 		}
 		
 		/// <inheritdoc/>
@@ -49,7 +50,7 @@ namespace ICSharpCode.AvalonEdit.Folding
 				double yPos = m.VisualLine.GetTextLineVisualYPosition(textLine, VisualYPosition.LineTop) - TextView.VerticalOffset;
 				yPos += (textLine.Height - m.DesiredSize.Height) / 2;
 				double xPos = (finalSize.Width - m.DesiredSize.Width) / 2;
-				m.Arrange(new Rect(new Point(xPos, yPos), m.DesiredSize));
+				m.Arrange(new Rect(PixelSnapHelpers.Round(new Point(xPos, yPos)), m.DesiredSize));
 			}
 			return base.ArrangeOverride(finalSize);
 		}
@@ -84,7 +85,6 @@ namespace ICSharpCode.AvalonEdit.Folding
 					if (fs.StartOffset <= line.LastDocumentLine.Offset + line.LastDocumentLine.Length) {
 						FoldingMarginMarker m = new FoldingMarginMarker {
 							IsExpanded = !fs.IsFolded,
-							SnapsToDevicePixels = true,
 							VisualLine = line,
 							FoldingSection = fs
 						};
@@ -208,6 +208,10 @@ namespace ICSharpCode.AvalonEdit.Folding
 		/// </summary>
 		void DrawFoldLines(DrawingContext drawingContext, Pen[] colors, Pen[] endMarker)
 		{
+			// Because we are using PenLineCap.Flat (the default), for vertical lines,
+			// Y coordinates must be on pixel boundaries, whereas the X coordinate must be in the
+			// middle of a pixel. (and the other way round for horizontal lines)
+			Size pixelSize = PixelSnapHelpers.GetPixelSize();
 			double markerXPos = PixelSnapHelpers.PixelAlign(RenderSize.Width / 2);
 			double startY = 0;
 			Pen currentPen = colors[0];
@@ -216,12 +220,12 @@ namespace ICSharpCode.AvalonEdit.Folding
 				foreach (TextLine tl in vl.TextLines) {
 					if (endMarker[tlNumber] != null) {
 						double visualPos = GetVisualPos(vl, tl);
-						drawingContext.DrawLine(endMarker[tlNumber], new Point(markerXPos, visualPos), new Point(RenderSize.Width, visualPos));
+						drawingContext.DrawLine(endMarker[tlNumber], new Point(markerXPos - pixelSize.Width / 2, visualPos), new Point(RenderSize.Width, visualPos));
 					}
 					if (colors[tlNumber + 1] != currentPen) {
 						double visualPos = GetVisualPos(vl, tl);
 						if (currentPen != null) {
-							drawingContext.DrawLine(currentPen, new Point(markerXPos, startY), new Point(markerXPos, visualPos));
+							drawingContext.DrawLine(currentPen, new Point(markerXPos, startY + pixelSize.Height / 2), new Point(markerXPos, visualPos - pixelSize.Height / 2));
 						}
 						currentPen = colors[tlNumber + 1];
 						startY = visualPos;
@@ -230,14 +234,14 @@ namespace ICSharpCode.AvalonEdit.Folding
 				}
 			}
 			if (currentPen != null) {
-				drawingContext.DrawLine(currentPen, new Point(markerXPos, startY), new Point(markerXPos, RenderSize.Height));
+				drawingContext.DrawLine(currentPen, new Point(markerXPos, startY + pixelSize.Height / 2), new Point(markerXPos, RenderSize.Height));
 			}
 		}
 		
 		double GetVisualPos(VisualLine vl, TextLine tl)
 		{
 			double pos = vl.GetTextLineVisualYPosition(tl, VisualYPosition.LineTop) + tl.Height / 2 - TextView.VerticalOffset;
-			return Math.Round(pos) + 0.5;
+			return PixelSnapHelpers.PixelAlign(pos);
 		}
 		
 		int GetTextLineIndexFromOffset(List<TextLine> textLines, int offset)

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Folding/FoldingMarginMarker.cs

@@ -12,6 +12,7 @@ using System.Windows.Input;
 using System.Windows.Media;
 
 using ICSharpCode.AvalonEdit.Rendering;
+using ICSharpCode.AvalonEdit.Utils;
 
 namespace ICSharpCode.AvalonEdit.Folding
 {
@@ -50,23 +51,26 @@ namespace ICSharpCode.AvalonEdit.Folding
 		protected override Size MeasureCore(Size availableSize)
 		{
 			double size = MarginSizeFactor * FoldingMargin.SizeFactor * (double)GetValue(TextBlock.FontSizeProperty);
-			size = Math.Round(size);
-			if (Math.Abs((size % 2) - 1) < 0.001) {
-				size -= 1;
-			}
+			size = PixelSnapHelpers.RoundToOdd(size);
 			return new Size(size, size);
 		}
 		
 		protected override void OnRender(DrawingContext drawingContext)
 		{
 			Pen blackPen = new Pen(Brushes.Black, 1);
-			Rect rect = new Rect(new Point(0.5, 0.5), this.RenderSize);
+			blackPen.StartLineCap = PenLineCap.Square;
+			blackPen.EndLineCap = PenLineCap.Square;
+			Size pixelSize = PixelSnapHelpers.GetPixelSize();
+			Rect rect = new Rect(pixelSize.Width / 2,
+			                     pixelSize.Height / 2,
+			                     this.RenderSize.Width - pixelSize.Width,
+			                     this.RenderSize.Height - pixelSize.Height);
 			drawingContext.DrawRectangle(Brushes.White,
 			                             IsMouseDirectlyOver ? blackPen : new Pen(Brushes.Gray, 1),
 			                             rect);
 			double middleX = rect.Left + rect.Width / 2;
 			double middleY = rect.Top + rect.Height / 2;
-			double space = Math.Round(rect.Width / 8) + 1;
+			double space = PixelSnapHelpers.Round(rect.Width / 8) + pixelSize.Width;
 			drawingContext.DrawLine(blackPen,
 			                        new Point(rect.Left + space, middleY),
 			                        new Point(rect.Right - space, middleY));

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/BackgroundGeometryBuilder.cs

@@ -44,8 +44,10 @@ namespace ICSharpCode.AvalonEdit.Rendering
 		/// </summary>
 		public void AddSegment(TextView textView, ISegment segment)
 		{
-			foreach (Rect r in GetRectsForSegment(textView, segment))
-				AddRectangle(r.Left, r.Top, r.Right, r.Bottom);
+			foreach (Rect r in GetRectsForSegment(textView, segment)) {
+				Rect roundedRect = PixelSnapHelpers.PixelAlign(r);
+				AddRectangle(roundedRect.Left, roundedRect.Top, roundedRect.Right, roundedRect.Bottom);
+			}
 		}
 		
 		/// <summary>

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Utils/PixelSnapHelpers.cs

@@ -12,18 +12,67 @@ namespace ICSharpCode.AvalonEdit.Utils
 {
 	static class PixelSnapHelpers
 	{
+		public static Size GetPixelSize()
+		{
+			return new Size(1, 1);
+		}
+		
+		/// <summary>
+		/// Aligns val on the next middle of a pixel.
+		/// </summary>
 		public static double PixelAlign(double val)
 		{
+			// 0 -> 0.5
+			// 0.1 -> 0.5
+			// 0.5 -> 0.5
+			// 0.9 -> 0.5
+			// 1 -> 1.5
 			return Math.Round(val + 0.5) - 0.5;
 		}
 		
-		public static Rect ToPixels(Rect rect)
+		/// <summary>
+		/// Aligns the borders of rect on the middles of pixels.
+		/// </summary>
+		public static Rect PixelAlign(Rect rect)
 		{
 			rect.X = PixelAlign(rect.X);
 			rect.Y = PixelAlign(rect.Y);
-			rect.Width = Math.Round(rect.Width);
-			rect.Height = Math.Round(rect.Height);
+			rect.Width = Round(rect.Width);
+			rect.Height = Round(rect.Height);
 			return rect;
 		}
+		
+		public static Point Round(Point val)
+		{
+			return new Point(Round(val.X), Round(val.Y));
+		}
+		
+		/// <summary>
+		/// Rounds val to a whole number of pixels.
+		/// </summary>
+		public static double Round(double val)
+		{
+			return Math.Round(val);
+		}
+		
+		/// <summary>
+		/// Rounds val to an even number of pixels.
+		/// </summary>
+		public static double RoundToEven(double val)
+		{
+			// 0 -> 0
+			// 1 -> 2
+			// 2 -> 2
+			// 3 -> 4
+			return Math.Round(val / 2) * 2;
+		}
+		
+		/// <summary>
+		/// Rounds val to an odd number of pixels.
+		/// </summary>
+		public static double RoundToOdd(double val)
+		{
+			return RoundToEven(val - 1) + 1;
+		}
 	}
 }