Fixed bug in Arc when EndAngle is smaller than StartAngle.

arklumpus · May 28, 2020 · aae74c9 · aae74c9
1 parent e750230
commit aae74c9
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Showing 2 changed files with 70 additions and 11 deletions.
diff --git a/VectSharp/Graphics.cs b/VectSharp/Graphics.cs
@@ -775,19 +775,78 @@ public Segment[] ToBezierSegments()
         {
             List<Segment> tbr = new List<Segment>();
 
-            if (EndAngle - StartAngle <= Math.PI / 2)
+            if (EndAngle > StartAngle)
             {
-                tbr.AddRange(GetBezierSegment(Points[0].X, Points[0].Y, Radius, StartAngle, EndAngle, true));
+                if (EndAngle - StartAngle <= Math.PI / 2)
+                {
+                    tbr.AddRange(GetBezierSegment(Points[0].X, Points[0].Y, Radius, StartAngle, EndAngle, true));
+                }
+                else
+                {
+                    int count = (int)Math.Ceiling(2 * (EndAngle - StartAngle) / Math.PI);
+                    double angle = StartAngle;
+
+                    for (int i = 0; i < count; i++)
+                    {
+                        tbr.AddRange(GetBezierSegment(Points[0].X, Points[0].Y, Radius, angle, angle + (EndAngle - StartAngle) / count, i == 0));
+                        angle += (EndAngle - StartAngle) / count;
+                    }
+                }
             }
-            else
+            else if (EndAngle < StartAngle)
             {
-                int count = (int)Math.Ceiling(2 * (EndAngle - StartAngle) / Math.PI);
-                double angle = StartAngle;
+                Point startPoint = new Point(Points[0].X + Radius * Math.Cos(EndAngle), Points[0].Y + Radius * Math.Sin(EndAngle));
+                if (StartAngle - EndAngle <= Math.PI / 2)
+                {
+                    tbr.AddRange(GetBezierSegment(Points[0].X, Points[0].Y, Radius, EndAngle, StartAngle, true));
+                }
+                else
+                {
+                    int count = (int)Math.Ceiling(2 * (StartAngle - EndAngle) / Math.PI);
+                    double angle = EndAngle;
 
-                for (int i = 0; i < count; i++)
+                    for (int i = 0; i < count; i++)
+                    {
+                        tbr.AddRange(GetBezierSegment(Points[0].X, Points[0].Y, Radius, angle, angle + (StartAngle - EndAngle) / count, i == 0));
+                        angle += (StartAngle - EndAngle) / count;
+                    }
+                }
+
+                return ReverseSegments(tbr, startPoint).ToArray();
+            }
+
+            return tbr.ToArray();
+        }
+
+        private static Segment[] ReverseSegments(IReadOnlyList<Segment> originalSegments, Point startPoint)
+        {
+            List<Segment> tbr = new List<Segment>(originalSegments.Count);
+
+            for (int i = originalSegments.Count - 1; i >= 0; i--)
+            {
+                switch (originalSegments[i].Type)
                 {
-                    tbr.AddRange(GetBezierSegment(Points[0].X, Points[0].Y, Radius, angle, angle + (EndAngle - StartAngle) / count, i == 0));
-                    angle += (EndAngle - StartAngle) / count;
+                    case SegmentType.Line:
+                        if (i > 0)
+                        {
+                            tbr.Add(new LineSegment(originalSegments[i - 1].Point));
+                        }
+                        else
+                        {
+                            tbr.Add(new LineSegment(startPoint));
+                        }
+                        break;
+                    case SegmentType.CubicBezier:
+                        CubicBezierSegment originalSegment = (CubicBezierSegment)originalSegments[i];
+                        if (i > 0)
+                        {
+                            tbr.Add(new CubicBezierSegment(originalSegment.Points[1], originalSegment.Points[0], originalSegments[i - 1].Point));
+                        }
+                        else
+                        {
+                            tbr.Add(new CubicBezierSegment(originalSegment.Points[1], originalSegment.Points[0], startPoint));
+                        }
+                        break;
                 }
             }
 

diff --git a/VectSharp/VectSharp.csproj b/VectSharp/VectSharp.csproj
@@ -5,9 +5,9 @@
     <Authors>Giorgio Bianchini</Authors>
     <Company>University of Bristol</Company>
     <Description>A library to produce vector graphics (including text) without too many dependencies. Extensible to support multiple output formats. This is the base package, and does not provide any output formats. For more information, see https://github.com/arklumpus/VectSharp</Description>
-    <Version>1.2.0</Version>
-    <AssemblyVersion>1.2.0.0</AssemblyVersion>
-    <FileVersion>1.2.0.0</FileVersion>
+    <Version>1.2.1</Version>
+    <AssemblyVersion>1.2.1.0</AssemblyVersion>
+    <FileVersion>1.2.1.0</FileVersion>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">