color blend: fixed gradient's stops order

Source/Painting/SvgGradientServer.cs

-using System;
 using System.Collections.Generic;
-using System.Collections;
-using System.Text;
 using System.Drawing;
 using System.Drawing.Drawing2D;
 
@@ -106,13 +103,14 @@ namespace Svg
         /// <param name="opacity">The opacity of the colour blend.</param>
         protected ColorBlend GetColourBlend(SvgVisualElement owner, float opacity)
         {
-            ColorBlend blend = new ColorBlend();
             int colourBlends = this.Stops.Count;
             bool insertStart = false;
             bool insertEnd = false;
 
             //gradient.Transform = renderingElement.Transforms.Matrix;
 
+            //stops should be processed in reverse order
+
             // May need to increase the number of colour blends because the range *must* be from 0.0 to 1.0.
             // E.g. 0.5 - 0.8 isn't valid therefore the rest need to be calculated.
 
@@ -120,8 +118,8 @@ namespace Svg
             if (this.Stops[0].Offset.Value > 0)
             {
                 colourBlends++;
-                // Indicate that a colour has to be dynamically added at the start
-                insertStart = true;
+                // Indicate that a colour has to be dynamically added at the end
+                insertEnd = true;
             }
 
             // If the last stop doesn't end at 1 a stop
@@ -129,12 +127,11 @@ namespace Svg
             if (lastValue < 100 || lastValue < 1)
             {
                 colourBlends++;
-                // Indicate that a colour has to be dynamically added at the end
-                insertEnd = true;
+                // Indicate that a colour has to be dynamically added at the start
+                insertStart = true;
             }
 
-            blend.Positions = new float[colourBlends];
-            blend.Colors = new Color[colourBlends];
+            ColorBlend blend = new ColorBlend(colourBlends);
 
             // Set positions and colour values
             int actualStops = 0;
@@ -144,15 +141,21 @@ namespace Svg
 
             for (int i = 0; i < colourBlends; i++)
             {
-                mergedOpacity = opacity * this.Stops[actualStops].Opacity;
-                position = (this.Stops[actualStops].Offset.ToDeviceValue(owner) / owner.Bounds.Width);
-                colour = Color.FromArgb((int)(mergedOpacity * 255), this.Stops[actualStops++].Colour);
+                var currentStop = this.Stops[this.Stops.Count - 1 - actualStops];
+
+                mergedOpacity = opacity * currentStop.Opacity;
+                position = 1 - (currentStop.Offset.ToDeviceValue(owner) / owner.Bounds.Width);
+                colour = Color.FromArgb((int)(mergedOpacity * 255), currentStop.Colour);
+
+                actualStops++;
 
                 // Insert this colour before itself at position 0
                 if (insertStart && i == 0)
                 {
                     blend.Positions[i] = 0.0f;
-                    blend.Colors[i++] = colour;
+                    blend.Colors[i] = colour;
+
+                    i++;
                 }
 
                 blend.Positions[i] = position;
@@ -161,8 +164,10 @@ namespace Svg
                 // Insert this colour after itself at position 0
                 if (insertEnd && i == colourBlends - 2)
                 {
-                    blend.Positions[i + 1] = 1.0f;
-                    blend.Colors[++i] = colour;
+                    i++;
+
+                    blend.Positions[i] = 1.0f;
+                    blend.Colors[i] = colour;
                 }
             }
 
@@ -184,12 +189,12 @@ namespace Svg
 		public override SvgElement DeepCopy<T>()
 		{
 			var newObj = base.DeepCopy<T>() as SvgGradientServer;
-			newObj.SpreadMethod = this.SpreadMethod;
+			
+            newObj.SpreadMethod = this.SpreadMethod;
 			newObj.GradientUnits = this.GradientUnits;
 			newObj.InheritGradient = this.InheritGradient;
-			return newObj;
 
+			return newObj;
 		}
-
     }
 }
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Source/Painting/SvgRadialGradientServer.cs

-using System;
-using System.Collections.Generic;
-using System.Text;
 using System.Drawing;
 using System.Drawing.Drawing2D;
 
@@ -79,33 +76,35 @@ namespace Svg
 
         public override Brush GetBrush(SvgVisualElement renderingElement, float opacity)
         {
-            GraphicsPath path = new GraphicsPath();
-            float left = this.CenterX.ToDeviceValue(renderingElement);
-            float top = this.CenterY.ToDeviceValue(renderingElement, true);
             float radius = this.Radius.ToDeviceValue(renderingElement);
-            RectangleF boundingBox = (this.GradientUnits == SvgCoordinateUnits.ObjectBoundingBox) ? renderingElement.Bounds : renderingElement.OwnerDocument.GetDimensions();
 
-            if (radius > 0)
+            if (radius <= 0)
             {
-                path.AddEllipse(
-                    boundingBox.Left + left - radius,
-                    boundingBox.Top + top - radius,
-                    radius * 2,
-                    radius * 2);
-
-                PathGradientBrush brush = new PathGradientBrush(path);
-                ColorBlend blend = base.GetColourBlend(renderingElement, opacity);
-
-                brush.InterpolationColors = blend;
-                brush.CenterPoint =
-                    new PointF(
-                        boundingBox.Left + this.FocalX.ToDeviceValue(renderingElement),
-                        boundingBox.Top + this.FocalY.ToDeviceValue(renderingElement, true));
-
-                return brush;
+                return null;
             }
             
-            return null;            
+            GraphicsPath path = new GraphicsPath();
+            float left = this.CenterX.ToDeviceValue(renderingElement);
+            float top = this.CenterY.ToDeviceValue(renderingElement, true);
+            
+            RectangleF boundingBox = (this.GradientUnits == SvgCoordinateUnits.ObjectBoundingBox) ? renderingElement.Bounds : renderingElement.OwnerDocument.GetDimensions();
+
+            path.AddEllipse(
+                boundingBox.Left + left - radius,
+                boundingBox.Top + top - radius,
+                radius * 2,
+                radius * 2);
+
+            PathGradientBrush brush = new PathGradientBrush(path);
+            ColorBlend blend = base.GetColourBlend(renderingElement, opacity);
+
+            brush.InterpolationColors = blend;
+            brush.CenterPoint =
+                new PointF(
+                    boundingBox.Left + this.FocalX.ToDeviceValue(renderingElement),
+                    boundingBox.Top + this.FocalY.ToDeviceValue(renderingElement, true));
+
+            return brush;
         }
 
 
@@ -118,13 +117,14 @@ namespace Svg
 		public override SvgElement DeepCopy<T>()
 		{
 			var newObj = base.DeepCopy<T>() as SvgRadialGradientServer;
+
 			newObj.CenterX = this.CenterX;
 			newObj.CenterY = this.CenterY;
 			newObj.Radius = this.Radius;
 			newObj.FocalX = this.FocalX;
 			newObj.FocalY = this.FocalY;
-			return newObj;
 
+			return newObj;
 		}
     }
 }
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