Bug fixes: Gradients and Filters

- Support of generic fonts (serif, sans-serif, monospace)
- Initial support of filters
- Fixes to gradient rendering

Source/Basic Shapes/SvgVisualElement.cs

@@ -99,34 +99,66 @@ namespace Svg
             this._requiresSmoothRendering = false;
         }
 
+        protected virtual bool Renderable { get { return true; } }
+
         /// <summary>
         /// Renders the <see cref="SvgElement"/> and contents to the specified <see cref="Graphics"/> object.
         /// </summary>
         /// <param name="renderer">The <see cref="SvgRenderer"/> object to render to.</param>
         protected override void Render(SvgRenderer renderer)
         {
-            if ((this.Path(renderer) != null) && this.Visible && this.Displayable)
+            this.Render(renderer, true);
+        }
+
+        private void Render(SvgRenderer renderer, bool renderFilter)
+        {
+            if (this.Visible && this.Displayable && this.PushTransforms(renderer) &&
+                (!Renderable || this.Path(renderer) != null))
             {
-                this.PushTransforms(renderer);
-                this.SetClip(renderer);
+                bool renderNormal = true;
 
-                // If this element needs smoothing enabled turn anti-aliasing on
-                if (this.RequiresSmoothRendering)
+                if (renderFilter && this.Filter != null)
                 {
-                    renderer.SmoothingMode = SmoothingMode.AntiAlias;
+                    var filter = this.OwnerDocument.IdManager.GetElementById(this.Filter) as FilterEffects.SvgFilter;
+                    if (filter != null)
+                    {
+                        this.PopTransforms(renderer);
+                        filter.ApplyFilter(this, renderer, (r) => this.Render(r, false));
+                        renderNormal = false;
+                    }
                 }
 
-                this.RenderFill(renderer);
-                this.RenderStroke(renderer);
 
-                // Reset the smoothing mode
-                if (this.RequiresSmoothRendering && renderer.SmoothingMode == SmoothingMode.AntiAlias)
+                if (renderNormal)
                 {
-                    renderer.SmoothingMode = SmoothingMode.Default;
+                    this.SetClip(renderer);
+
+                    if (Renderable)
+                    {
+                        // If this element needs smoothing enabled turn anti-aliasing on
+                        if (this.RequiresSmoothRendering)
+                        {
+                            renderer.SmoothingMode = SmoothingMode.AntiAlias;
+                        }
+
+                        this.RenderFill(renderer);
+                        this.RenderStroke(renderer);
+
+                        // Reset the smoothing mode
+                        if (this.RequiresSmoothRendering && renderer.SmoothingMode == SmoothingMode.AntiAlias)
+                        {
+                            renderer.SmoothingMode = SmoothingMode.Default;
+                        }
+                    }
+                    else
+                    {
+                        base.RenderChildren(renderer);
+                    }
+
+                    this.ResetClip(renderer);
+                    this.PopTransforms(renderer);
                 }
 
-                this.ResetClip(renderer);
-                this.PopTransforms(renderer);
             }
         }
 

Source/Basic Shapes/SvgVisualElementStyle.cs

 using System;
 using System.Collections.Generic;
+using System.Drawing;
 using System.Text;
 using System.Reflection;
 using System.ComponentModel;
@@ -53,6 +54,16 @@ namespace Svg
             }
         }
 
+        /// <summary>
+        /// Gets or sets the fill <see cref="SvgPaintServer"/> of this element.
+        /// </summary>
+        [SvgAttribute("enable-background")]
+        public virtual string EnableBackground
+        {
+            get { return this.Attributes["enable-background"] as string; }
+            set { this.Attributes["enable-background"] = value; }
+        }
+
         /// <summary>
         /// Gets or sets the fill <see cref="SvgPaintServer"/> of this element.
         /// </summary>
@@ -361,26 +372,43 @@ namespace Svg
                     break;
             }
 
+            var family = ValidateFontFamily(this.FontFamily);
+            if (!family.IsStyleAvailable(fontStyle))
+            {
+                // Do Something
+            }
+
             // Get the font-family
-            string family = ValidateFontFamily(this.FontFamily) ?? DefaultFontFamily;
             return new System.Drawing.Font(family, fontSize, fontStyle, System.Drawing.GraphicsUnit.Pixel);
         }
 
-        private static string ValidateFontFamily(string fontFamilyList)
+        private static FontFamily ValidateFontFamily(string fontFamilyList)
         {
             // Split font family list on "," and then trim start and end spaces and quotes.
             var fontParts = (fontFamilyList ?? "").Split(new[] { ',' }).Select(fontName => fontName.Trim(new[] { '"', ' ', '\'' }));
-
             var families = System.Drawing.FontFamily.Families;
+            FontFamily family;
 
             // Find a the first font that exists in the list of installed font families.
             //styles from IE get sent through as lowercase.
-            foreach (var f in fontParts.Where(f => families.Any(family => family.Name.ToLower() == f.ToLower())))
+            foreach (var f in fontParts)
             {
-                return f;
+                family = families.FirstOrDefault(ff => ff.Name.ToLower() == f.ToLower());
+                if (family != null) return family;
+
+                switch (f)
+                {
+                    case "serif":
+                        return System.Drawing.FontFamily.GenericSerif;
+                    case "sans-serif":
+                        return System.Drawing.FontFamily.GenericSansSerif;
+                    case "monospace":
+                        return System.Drawing.FontFamily.GenericMonospace;
+                }
             }
+
             // No valid font family found from the list requested.
-            return null;
+            return System.Drawing.FontFamily.GenericSansSerif;
         }
 
     }

Source/DataTypes/SvgUnitCollection.cs

@@ -23,6 +23,12 @@ namespace Svg
 
             return ret;
         }
+
+        public static bool IsNullOrEmpty(SvgUnitCollection collection)
+        {
+            return collection == null || collection.Count < 1 ||
+                (collection.Count == 1 && (collection[0] == SvgUnit.Empty || collection[0] == SvgUnit.None));
+        }
     }
 
     /// <summary>

Source/Document Structure/SvgGroup.cs

@@ -56,23 +56,25 @@ namespace Svg
             }
         }
 
-        /// <summary>
-        /// Renders the <see cref="SvgElement"/> and contents to the specified <see cref="Graphics"/> object.
-        /// </summary>
-        /// <param name="graphics">The <see cref="Graphics"/> object to render to.</param>
-        protected override void Render(SvgRenderer renderer)
-        {
-            if (!Visible || !Displayable)
-                return;
+        protected override bool Renderable { get { return false; } }
 
-            if (this.PushTransforms(renderer))
-            {
-                this.SetClip(renderer);
-                base.RenderChildren(renderer);
-                this.ResetClip(renderer);
-                this.PopTransforms(renderer);
-            }
-        }
+        ///// <summary>
+        ///// Renders the <see cref="SvgElement"/> and contents to the specified <see cref="Graphics"/> object.
+        ///// </summary>
+        ///// <param name="graphics">The <see cref="Graphics"/> object to render to.</param>
+        //protected override void Render(SvgRenderer renderer)
+        //{
+        //    if (!Visible || !Displayable)
+        //        return;
+
+        //    if (this.PushTransforms(renderer))
+        //    {
+        //        this.SetClip(renderer);
+        //        base.RenderChildren(renderer);
+        //        this.ResetClip(renderer);
+        //        this.PopTransforms(renderer);
+        //    }
+        //}
 
         
         public override SvgElement DeepCopy()

Source/Document Structure/SvgUse.cs

@@ -77,6 +77,8 @@ namespace Svg
         //            }
         //        }
 
+        protected override bool Renderable { get { return false; } }
+
         protected override void Render(SvgRenderer renderer)
         {
             if (!Visible || !Displayable)

Source/Extensibility/SvgForeignObject.cs

@@ -56,21 +56,23 @@ namespace Svg
             }
         }
 
-        /// <summary>
-        /// Renders the <see cref="SvgElement"/> and contents to the specified <see cref="Graphics"/> object.
-        /// </summary>
-        /// <param name="renderer">The <see cref="Graphics"/> object to render to.</param>
-        protected override void Render(SvgRenderer renderer)
-        {
-            if (!Visible || !Displayable)
-                return;
+        protected override bool Renderable { get { return false; } }
 
-            this.PushTransforms(renderer);
-            this.SetClip(renderer);
-            base.RenderChildren(renderer);
-            this.ResetClip(renderer);
-            this.PopTransforms(renderer);
-        }
+        ///// <summary>
+        ///// Renders the <see cref="SvgElement"/> and contents to the specified <see cref="Graphics"/> object.
+        ///// </summary>
+        ///// <param name="renderer">The <see cref="Graphics"/> object to render to.</param>
+        //protected override void Render(SvgRenderer renderer)
+        //{
+        //    if (!Visible || !Displayable)
+        //        return;
+
+        //    this.PushTransforms(renderer);
+        //    this.SetClip(renderer);
+        //    base.RenderChildren(renderer);
+        //    this.ResetClip(renderer);
+        //    this.PopTransforms(renderer);
+        //}
 
         public override SvgElement DeepCopy()
         {

Source/External/ExCSS/Parser.cs

@@ -7,6 +7,28 @@ using ExCSS.Model.TextBlocks;
 // ReSharper disable once CheckNamespace
 using System;
 
+//The MIT License (MIT)
+
+//Copyright (c) [year] [fullname]
+
+//Permission is hereby granted, free of charge, to any person obtaining a copy
+//of this software and associated documentation files (the "Software"), to deal
+//in the Software without restriction, including without limitation the rights
+//to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//copies of the Software, and to permit persons to whom the Software is
+//furnished to do so, subject to the following conditions:
+
+//The above copyright notice and this permission notice shall be included in all
+//copies or substantial portions of the Software.
+
+//THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//SOFTWARE.
+
 
 namespace ExCSS
 {

Source/Filter Effects/ImageBuffer.cs

+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Drawing;
+using System.Drawing.Imaging;
+using System.Drawing.Drawing2D;
+
+namespace Svg.FilterEffects
+{
+    public class ImageBuffer : IDictionary<string, Bitmap>
+    {
+        private const string BufferKey = "__!!BUFFER";
+
+        private Dictionary<string, Bitmap> _images;
+        private RectangleF _bounds;
+        private SvgRenderer _renderer;
+        private Action<SvgRenderer> _renderMethod;
+        private float _inflate;
+
+        public Matrix Transform { get; set; }
+
+        public Bitmap Buffer
+        {
+            get { return _images[BufferKey]; }
+        }
+        public int Count
+        {
+            get { return _images.Count; }
+        }
+        public Bitmap this[string key]
+        {
+            get
+            {
+                return ProcessResult(key, _images[ProcessKey(key)]);
+            }
+            set
+            {
+                _images[ProcessKey(key)] = value;
+                if (key != null) _images[BufferKey] = value;
+            }
+        }
+
+        public ImageBuffer(RectangleF bounds, float inflate, SvgRenderer renderer, Action<SvgRenderer> renderMethod)
+        {
+            _bounds = bounds;
+            _inflate = inflate;
+            _renderer = renderer;
+            _renderMethod = renderMethod;
+            _images = new Dictionary<string, Bitmap>();
+            _images[SvgFilterPrimitive.BackgroundAlpha] = null;
+            _images[SvgFilterPrimitive.BackgroundImage] = null;
+            _images[SvgFilterPrimitive.FillPaint] = null;
+            _images[SvgFilterPrimitive.SourceAlpha] = null;
+            _images[SvgFilterPrimitive.SourceGraphic] = null;
+            _images[SvgFilterPrimitive.StrokePaint] = null;
+        }
+
+        public void Add(string key, Bitmap value)
+        {
+            _images.Add(ProcessKey(key), value);
+        }
+        public bool ContainsKey(string key)
+        {
+            return _images.ContainsKey(ProcessKey(key));
+        }
+        public void Clear()
+        {
+            _images.Clear();
+        }
+        public IEnumerator<KeyValuePair<string, Bitmap>> GetEnumerator()
+        {
+            return _images.GetEnumerator();
+        }
+        public bool Remove(string key)
+        {
+            switch (key)
+            {
+                case SvgFilterPrimitive.BackgroundAlpha:
+                case SvgFilterPrimitive.BackgroundImage:
+                case SvgFilterPrimitive.FillPaint:
+                case SvgFilterPrimitive.SourceAlpha:
+                case SvgFilterPrimitive.SourceGraphic:
+                case SvgFilterPrimitive.StrokePaint:
+                    return false;
+                default:
+                    return _images.Remove(ProcessKey(key));
+            }
+        }
+        public bool TryGetValue(string key, out Bitmap value)
+        {
+            if (_images.TryGetValue(ProcessKey(key), out value))
+            {
+                value = ProcessResult(key, value);
+                return true;
+            }
+            else
+            {
+                return false;
+            }
+        }
+
+        private Bitmap ProcessResult(string key, Bitmap curr)
+        {
+            if (curr == null)
+            {
+                switch (key)
+                {
+                    case SvgFilterPrimitive.BackgroundAlpha:
+                    case SvgFilterPrimitive.BackgroundImage:
+                    case SvgFilterPrimitive.FillPaint:
+                    case SvgFilterPrimitive.StrokePaint:
+                        // Do nothing
+                        return null;
+                    case SvgFilterPrimitive.SourceAlpha:
+                        _images[key] = CreateSourceAlpha();
+                        return _images[key];
+                    case SvgFilterPrimitive.SourceGraphic:
+                        _images[key] = CreateSourceGraphic();
+                        return _images[key];
+                }
+            }
+            return curr;
+        }
+        private string ProcessKey(string key)
+        {
+            if (string.IsNullOrEmpty(key)) return BufferKey;
+            return key;
+        }
+
+        
+
+        private Bitmap CreateSourceGraphic()
+        {
+            var graphic = new Bitmap((int)(_bounds.Width + 2 * _inflate * _bounds.Width + _bounds.X),
+                                     (int)(_bounds.Height + 2 * _inflate * _bounds.Height + _bounds.Y));
+            using (var renderer = SvgRenderer.FromImage(graphic))
+            {
+                renderer.Boundable(_renderer.Boundable());
+                var transform = new Matrix();
+                transform.Translate(_bounds.Width * _inflate, _bounds.Height * _inflate);
+                renderer.Transform = transform;
+                //renderer.Transform = _renderer.Transform;
+                //renderer.Clip = _renderer.Clip;
+                _renderMethod.Invoke(renderer);
+            }
+            return graphic;
+        }
+
+        private Bitmap CreateSourceAlpha()
+        {
+            Bitmap source = this[SvgFilterPrimitive.SourceGraphic];
+
+            float[][] colorMatrixElements = {
+                   new float[] {0, 0, 0, 0, 0},        // red
+                   new float[] {0, 0, 0, 0, 0},        // green
+                   new float[] {0, 0, 0, 0, 0},        // blue
+                   new float[] {0, 0, 0, 1, 1},        // alpha
+                   new float[] {0, 0, 0, 0, 0} };    // translations
+
+            var matrix = new ColorMatrix(colorMatrixElements);
+
+            ImageAttributes attributes = new ImageAttributes();
+            attributes.SetColorMatrix(matrix);
+
+            var sourceAlpha = new Bitmap(source.Width, source.Height);
+
+            using (var graphics = Graphics.FromImage(sourceAlpha))
+            {
+
+                graphics.DrawImage(source, new Rectangle(0, 0, source.Width, source.Height), 0, 0,
+                      source.Width, source.Height, GraphicsUnit.Pixel, attributes);
+                graphics.Save();
+            }
+
+            return sourceAlpha;
+        }
+
+
+
+        bool ICollection<KeyValuePair<string, Bitmap>>.IsReadOnly
+        {
+            get { return false; }
+        }
+        ICollection<string> IDictionary<string, Bitmap>.Keys
+        {
+            get { return _images.Keys; }
+        }
+        ICollection<Bitmap> IDictionary<string, Bitmap>.Values
+        {
+            get { return _images.Values; }
+        }
+
+        void ICollection<KeyValuePair<string, Bitmap>>.Add(KeyValuePair<string, Bitmap> item)
+        {
+            _images.Add(item.Key, item.Value);
+        }
+        bool ICollection<KeyValuePair<string, Bitmap>>.Contains(KeyValuePair<string, Bitmap> item)
+        {
+            return ((IDictionary<string, Bitmap>)_images).Contains(item);
+        }
+        void ICollection<KeyValuePair<string, Bitmap>>.CopyTo(KeyValuePair<string, Bitmap>[] array, int arrayIndex)
+        {
+            ((IDictionary<string, Bitmap>)_images).CopyTo(array, arrayIndex);
+        }
+        bool ICollection<KeyValuePair<string, Bitmap>>.Remove(KeyValuePair<string, Bitmap> item)
+        {
+            return _images.Remove(item.Key);
+        }
+        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
+        {
+            return _images.GetEnumerator();
+        }
+    }
+}

Source/Filter Effects/SvgFilter.cs

@@ -72,15 +72,11 @@ namespace Svg.FilterEffects
             set { this.Attributes["color-interpolation-filters"] = value; }
         }
 
-
-        internal Dictionary<string, Func<SvgVisualElement, SvgRenderer, Bitmap>> Buffer { get; private set; }
-
         /// <summary>
         /// Initializes a new instance of the <see cref="SvgFilter"/> class.
         /// </summary>
         public SvgFilter()
         {
-            this.Buffer = new Dictionary<string, Func<SvgVisualElement, SvgRenderer, Bitmap>>();
         }
 
         /// <summary>
@@ -103,10 +99,32 @@ namespace Svg.FilterEffects
             return (SvgFilter)this.MemberwiseClone();
         }
 
-        public void ApplyFilter(SvgVisualElement element, SvgRenderer renderer)
+        private Matrix GetTransform(SvgVisualElement element)
+        {
+            var transformMatrix = new Matrix();
+            foreach (var transformation in element.Transforms)
+            {
+                transformMatrix.Multiply(transformation.Matrix);
+            }
+            return transformMatrix;
+        }
+
+        private RectangleF GetPathBounds(SvgVisualElement element, SvgRenderer renderer, Matrix transform)
+        {
+            var bounds = element.Path(renderer).GetBounds();
+            var pts = new PointF[] { bounds.Location, new PointF(bounds.Right, bounds.Bottom) };
+            transform.TransformPoints(pts);
+
+            return new RectangleF(Math.Min(pts[0].X, pts[1].X), Math.Min(pts[0].Y, pts[1].Y),
+                                  Math.Abs(pts[0].X - pts[1].X), Math.Abs(pts[0].Y - pts[1].Y));
+        }
+
+        public void ApplyFilter(SvgVisualElement element, SvgRenderer renderer, Action<SvgRenderer> renderMethod)
         {
-            this.Buffer.Clear();
-            this.PopulateDefaults(element, renderer);
+            var inflate = 0.5f;
+            var transform = GetTransform(element);
+            var bounds = GetPathBounds(element, renderer, transform);
+            var buffer = new ImageBuffer(bounds, inflate, renderer, renderMethod) { Transform = transform };
 
             IEnumerable<SvgFilterPrimitive> primitives = this.Children.OfType<SvgFilterPrimitive>();
 
@@ -114,21 +132,21 @@ namespace Svg.FilterEffects
             {
                 foreach (var primitive in primitives)
                 {
-                    this.Buffer.Add(primitive.Result, (e, r) => primitive.Process());
+                    primitive.Process(buffer);
                 }
 
                 // Render the final filtered image
-                renderer.DrawImageUnscaled(this.Buffer.Last().Value(element, renderer), new Point(0, 0));
+                var bufferImg = buffer.Buffer;
+                bufferImg.Save(@"C:\test.png");
+                var imgDraw = RectangleF.Inflate(bounds, inflate * bounds.Width, inflate * bounds.Height);
+                var prevClip = renderer.Clip;
+                renderer.Clip = new Region(imgDraw);
+                renderer.DrawImage(bufferImg, imgDraw, new RectangleF(bounds.X, bounds.Y, imgDraw.Width, imgDraw.Height), GraphicsUnit.Pixel);
+                renderer.Clip = prevClip;
+                //renderer.DrawImage(bufferImg, bounds, bounds, GraphicsUnit.Pixel);
             }
         }
-
-        private void PopulateDefaults(SvgVisualElement element, SvgRenderer renderer)
-        {
-            this.ResetDefaults();
-
-            this.Buffer.Add(SvgFilterPrimitive.SourceGraphic, this.CreateSourceGraphic);
-            this.Buffer.Add(SvgFilterPrimitive.SourceAlpha, this.CreateSourceAlpha);
-        }
+                
 
         #region Defaults
 
@@ -147,58 +165,7 @@ namespace Svg.FilterEffects
             }
         }
 
-        private Bitmap CreateSourceGraphic(SvgVisualElement element, SvgRenderer renderer)
-        {
-            if (this.sourceGraphic == null)
-            {
-                RectangleF bounds = element.Path(renderer).GetBounds();
-                this.sourceGraphic = new Bitmap((int)bounds.Width, (int)bounds.Height);
-
-                using (var graphics = Graphics.FromImage(this.sourceGraphic))
-                {
-                    graphics.Clip = renderer.Clip;
-                    graphics.Transform = renderer.Transform;
-
-                    element.RenderElement(SvgRenderer.FromGraphics(graphics));
-
-                    graphics.Save();
-                }
-            }
-
-            return this.sourceGraphic;
-        }
-
-        private Bitmap CreateSourceAlpha(SvgVisualElement element, SvgRenderer renderer)
-        {
-            if (this.sourceAlpha == null)
-            {
-                Bitmap source = this.Buffer[SvgFilterPrimitive.SourceGraphic](element, renderer);
-
-                float[][] colorMatrixElements = {
-                   new float[] {0, 0, 0, 0, 0},        // red
-                   new float[] {0, 0, 0, 0, 0},        // green
-                   new float[] {0, 0, 0, 0, 0},        // blue
-                   new float[] {0, 0, 0, 1, 1},        // alpha
-                   new float[] {0, 0, 0, 0, 0} };    // translations
-
-                var matrix = new ColorMatrix(colorMatrixElements);
-
-                ImageAttributes attributes = new ImageAttributes();
-                attributes.SetColorMatrix(matrix);
-
-                this.sourceAlpha = new Bitmap(source.Width, source.Height);
-
-                using (var graphics = Graphics.FromImage(this.sourceAlpha))
-                {
-
-                    graphics.DrawImage(source, new Rectangle(0, 0, source.Width, source.Height), 0, 0,
-                          source.Width, source.Height, GraphicsUnit.Pixel, attributes);
-                    graphics.Save();
-                }
-            }
-
-            return this.sourceAlpha;
-        }
+        
         #endregion
 
 

Source/Filter Effects/SvgFilterPrimitive.cs

@@ -8,12 +8,12 @@ namespace Svg.FilterEffects
 {
     public abstract class SvgFilterPrimitive : SvgElement
     {
-        public static readonly string SourceGraphic = "SourceGraphic";
-        public static readonly string SourceAlpha = "SourceAlpha";
-        public static readonly string BackgroundImage = "BackgroundImage";
-        public static readonly string BackgroundAlpha = "BackgroundAlpha";
-        public static readonly string FillPaint = "FillPaint";
-        public static readonly string StrokePaint = "StrokePaint";
+        public const string SourceGraphic = "SourceGraphic";
+        public const string SourceAlpha = "SourceAlpha";
+        public const string BackgroundImage = "BackgroundImage";
+        public const string BackgroundAlpha = "BackgroundAlpha";
+        public const string FillPaint = "FillPaint";
+        public const string StrokePaint = "StrokePaint";
 
         [SvgAttribute("in")]
         public string Input
@@ -34,6 +34,6 @@ namespace Svg.FilterEffects
             get { return (SvgFilter)this.Parent; }
         }
 
-        public abstract Bitmap Process();
+        public abstract void Process(ImageBuffer buffer);
     }
 }
\ No newline at end of file

Source/Filter Effects/feColourMatrix/SvgColourMatrix.cs

 using System;
 using System.Drawing;
 using System.Collections.Generic;
-using Svg.Filter_Effects.feColourMatrix;
+using System.Linq;
+using System.Drawing.Imaging;
 
 namespace Svg.FilterEffects
 {
@@ -19,8 +20,7 @@ namespace Svg.FilterEffects
 		/// </summary>
 		[SvgAttribute("type")]
 		public SvgColourMatrixType Type { get; set; }
-
-
+        
 
 		/// <summary>
 		/// list of <number>s
@@ -29,13 +29,74 @@ namespace Svg.FilterEffects
 		/// </summary>
 		[SvgAttribute("values")]
 		public string Values { get; set; }
+        
 
+        public override void Process(ImageBuffer buffer)
+		{
+            var inputImage = buffer[this.Input];
 
+            float[][] colorMatrixElements;
+            float value;
+            switch (this.Type)
+            {
+                case SvgColourMatrixType.hueRotate:
+                    value = (string.IsNullOrEmpty(this.Values) ? 0 : float.Parse(this.Values));
+                    colorMatrixElements = new float[][] {
+                        new float[] {(float)(0.213 + Math.Cos(value) * +0.787 + Math.Sin(value) * -0.213),
+                                     (float)(0.715 + Math.Cos(value) * -0.715 + Math.Sin(value) * -0.715),
+                                     (float)(0.072 + Math.Cos(value) * -0.072 + Math.Sin(value) * +0.928), 0, 0},
+                        new float[] {(float)(0.213 + Math.Cos(value) * -0.213 + Math.Sin(value) * +0.143),
+                                     (float)(0.715 + Math.Cos(value) * +0.285 + Math.Sin(value) * +0.140),
+                                     (float)(0.072 + Math.Cos(value) * -0.072 + Math.Sin(value) * -0.283), 0, 0},
+                        new float[] {(float)(0.213 + Math.Cos(value) * -0.213 + Math.Sin(value) * -0.787),
+                                     (float)(0.715 + Math.Cos(value) * -0.715 + Math.Sin(value) * +0.715),
+                                     (float)(0.072 + Math.Cos(value) * +0.928 + Math.Sin(value) * +0.072), 0, 0},
+                        new float[] {0, 0, 0, 1, 0},
+                        new float[] {0, 0, 0, 0, 1}
+                    };
+                    break;
+                case SvgColourMatrixType.luminanceToAlpha:
+                    colorMatrixElements = new float[][] {
+                        new float[] {0, 0, 0, 0, 0},
+                        new float[] {0, 0, 0, 0, 0},
+                        new float[] {0, 0, 0, 0, 0},
+                        new float[] {0.2125f, 0.7154f, 0.0721f, 0, 0},
+                        new float[] {0, 0, 0, 0, 1}
+                    };
+                    break;
+                case SvgColourMatrixType.saturate:
+                    value = (string.IsNullOrEmpty(this.Values) ? 1 : float.Parse(this.Values));
+                    colorMatrixElements = new float[][] {
+                        new float[] {(float)(0.213+0.787*value), (float)(0.715-0.715*value), (float)(0.072-0.072*value), 0, 0},
+                        new float[] {(float)(0.213-0.213*value), (float)(0.715+0.285*value), (float)(0.072-0.072*value), 0, 0},
+                        new float[] {(float)(0.213-0.213*value), (float)(0.715-0.715*value), (float)(0.072+0.928*value), 0, 0},
+                        new float[] {0, 0, 0, 1, 0},
+                        new float[] {0, 0, 0, 0, 1}
+                    };
+                    break;
+                default: // Matrix
+                    var parts = this.Values.Split(new char[] { ' ', '\t', '\n', '\r', ',' });
+                    colorMatrixElements = new float[5][];
+                    for (int i = 0; i < 4; i++)
+                    {
+                        colorMatrixElements[i] = parts.Skip(i * 5).Take(5).Select(v => float.Parse(v)).ToArray();
+                    }
+                    colorMatrixElements[4] = new float[] { 0, 0, 0, 0, 1 };
+                    break;
+            }
 
+            var colorMatrix = new ColorMatrix(colorMatrixElements);
+            var imageAttrs = new ImageAttributes();
+            imageAttrs.SetColorMatrix(colorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
 
-		public override Bitmap Process()
-		{
-			return null;
+            var result = new Bitmap(inputImage.Width, inputImage.Height);
+            using (var g = Graphics.FromImage(result))
+            {
+                g.DrawImage(inputImage, new Rectangle(0, 0, inputImage.Width, inputImage.Height),
+                            0, 0, inputImage.Width, inputImage.Height, GraphicsUnit.Pixel, imageAttrs);
+                g.Flush();
+            }
+            buffer[this.Result] = result;
 		}
 
 

Source/Filter Effects/feColourMatrix/SvgColourMatrixType.cs

@@ -3,7 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 
-namespace Svg.Filter_Effects.feColourMatrix
+namespace Svg.FilterEffects
 {
 	public enum SvgColourMatrixType
 	{

Source/Filter Effects/feGaussianBlur/SvgGaussianBlur.cs

@@ -67,7 +67,10 @@ namespace Svg.FilterEffects
 
         public Bitmap Apply(Image inputImage)
         {
-            using (RawBitmap src = new RawBitmap(new Bitmap(inputImage)))
+            var bitmapSrc = inputImage as Bitmap;
+            if (bitmapSrc == null) bitmapSrc = new Bitmap(inputImage);
+
+            using (RawBitmap src = new RawBitmap(bitmapSrc))
             {
                 using (RawBitmap dest = new RawBitmap(new Bitmap(inputImage.Width, inputImage.Height)))
                 {
@@ -250,11 +253,11 @@ namespace Svg.FilterEffects
 
 
 
-        public override Bitmap Process()
+        public override void Process(ImageBuffer buffer)
         {
-            //Todo
-
-            return null;
+            var inputImage = buffer[this.Input];
+            var result = Apply(inputImage);
+            buffer[this.Result] = result;
         }
 
 

Source/Filter Effects/feMerge/SvgMerge.cs

@@ -5,44 +5,34 @@ using System.Text;
 using System.Drawing;
 using System.Drawing.Drawing2D;
 using System.Drawing.Imaging;
+using System.Linq;
 
 namespace Svg.FilterEffects
 {
-
 	[SvgElement("feMerge")]
     public class SvgMerge : SvgFilterPrimitive
     {
-        public StringCollection MergeResults { get; private set; }
-
-        public SvgMerge()
+        public override void Process(ImageBuffer buffer)
         {
-            MergeResults = new StringCollection();
+            var children = this.Children.OfType<SvgMergeNode>().ToList();
+            var inputImage = buffer[children.First().Input];
+            var result = new Bitmap(inputImage.Width, inputImage.Height);
+            using (var g = Graphics.FromImage(result))
+            {
+                foreach (var child in children)
+                {
+                    g.DrawImage(buffer[child.Input], new Rectangle(0, 0, inputImage.Width, inputImage.Height),
+                                0, 0, inputImage.Width, inputImage.Height, GraphicsUnit.Pixel);
+                }
+                g.Flush();
+            }
+            result.Save(@"C:\test.png");
+            buffer[this.Result] = result;
         }
 
-        public override Bitmap Process()
-        {
-			//Todo
-
-            //Bitmap merged = new Bitmap((int)this.Owner.Width.Value, (int)this.Owner.Height.Value); 
-            //Graphics mergedGraphics = Graphics.FromImage(merged);
-
-            //foreach (string resultId in this.MergeResults)
-            //{
-            //    mergedGraphics.DrawImageUnscaled(this.Owner.Results[resultId](), new Point(0, 0));
-            //}
-
-            //mergedGraphics.Save();
-            //mergedGraphics.Dispose();
-
-            //results.Add(this.Result, () => merged);
-
-            return null;
-        }
-
-
 		public override SvgElement DeepCopy()
 		{
-			throw new NotImplementedException();
+            return DeepCopy<SvgMerge>();
 		}
 
     }

Source/Filter Effects/feMerge/SvgMergeNode.cs

@@ -10,13 +10,13 @@ namespace Svg.FilterEffects
 {
 
 	[SvgElement("feMergeNode")]
-    public class SvgMergeNode : SvgFilterPrimitive
+    public class SvgMergeNode : SvgElement
     {
-        public override Bitmap Process()
+        [SvgAttribute("in")]
+        public string Input
         {
-            //Todo
-
-            return null;
+            get { return this.Attributes.GetAttribute<string>("in"); }
+            set { this.Attributes["in"] = value; }
         }
 
 		public override SvgElement DeepCopy()

Source/Filter Effects/feOffset/SvgOffset.cs

 using System;
 using System.Drawing;
 using System.Collections.Generic;
-using Svg.Filter_Effects.feColourMatrix;
 
 namespace Svg.FilterEffects
 {
@@ -28,13 +27,27 @@ namespace Svg.FilterEffects
 		/// Note: this is not used in calculations to bitmap - used only to allow for svg xml output
 		/// </summary>
 		[SvgAttribute("dy")]
-		public string Dy { get; set; }
+        public SvgUnit Dy { get; set; }
 
 
 
-		public override Bitmap Process()
+        public override void Process(ImageBuffer buffer)
 		{
-			return null;
+            var inputImage = buffer[this.Input];
+            var result = new Bitmap(inputImage.Width, inputImage.Height);
+
+            var pts = new PointF[] { new PointF(this.Dx.ToDeviceValue(null, UnitRenderingType.Horizontal, null), 
+                                                this.Dy.ToDeviceValue(null, UnitRenderingType.Vertical, null)) };
+            buffer.Transform.TransformVectors(pts);
+
+            using (var g = Graphics.FromImage(result))
+            {
+                g.DrawImage(inputImage, new Rectangle((int)pts[0].X, (int)pts[0].Y, 
+                                                      inputImage.Width, inputImage.Height),
+                            0, 0, inputImage.Width, inputImage.Height, GraphicsUnit.Pixel);
+                g.Flush();
+            }
+            buffer[this.Result] = result;
 		}
 
 

Source/Painting/SvgGradientServer.cs

@@ -111,7 +111,7 @@ namespace Svg
             }
         }
 
-        private Matrix EffectiveGradientTransform
+        protected Matrix EffectiveGradientTransform
         {
             get
             {
@@ -247,6 +247,15 @@ namespace Svg
             return newVector[0];
         }
 
+        protected float TransformDistance(float dist)
+        {
+            var newVector = new[] { new PointF(dist, 0) };
+
+            EffectiveGradientTransform.TransformVectors(newVector);
+
+            return (float)Math.Sqrt(Math.Pow(newVector[0].X, 2) + Math.Pow(newVector[0].Y, 2));
+        }
+
         protected static double CalculateDistance(PointF first, PointF second)
         {
             return Math.Sqrt(Math.Pow(first.X - second.X, 2) + Math.Pow(first.Y - second.Y, 2));

Source/Painting/SvgLinearGradientServer.cs

@@ -173,7 +173,7 @@ namespace Svg
 
             if (boundable.Bounds.Contains(specifiedEnd))
             {
-                effectiveEnd = CalculateClosestIntersectionPoint(effectiveEnd, intersectionPoints);
+                effectiveEnd = CalculateClosestIntersectionPoint(expandedEnd, intersectionPoints);
 
                 effectiveEnd = MovePointAlongVector(effectiveEnd, specifiedUnitVector, 1);
             }
@@ -296,48 +296,87 @@ namespace Svg
                 return result;
             }
 
+            /// <remarks>http://community.topcoder.com/tc?module=Static&d1=tutorials&d2=geometry2</remarks>
             private PointF? Intersection(LineF other)
             {
-                var a1 = Y2 - Y1;
-                var b1 = X1 - X2;
-                var c1 = X2 * Y1 - X1 * Y2;
+                const int precision = 8;
 
-                var r3 = a1 * other.X1 + b1 * other.Y1 + c1;
-                var r4 = a1 * other.X2 + b1 * other.Y2 + c1;
+                var a1 = (double)Y2 - Y1;
+                var b1 = (double)X1 - X2;
+                var c1 = a1 * X1 + b1 * Y1;
 
-                if (r3 != 0 && r4 != 0 && Math.Sign(r3) == Math.Sign(r4))
+                var a2 = (double)other.Y2 - other.Y1;
+                var b2 = (double)other.X1 - other.X2;
+                var c2 = a2 * other.X1 + b2 * other.Y1;
+
+                var det = a1 * b2 - a2 * b1;
+                if (det == 0)
                 {
                     return null;
                 }
+                else
+                {
+                    var xi = (b2 * c1 - b1 * c2) / det;
+                    var yi = (a1 * c2 - a2 * c1) / det;
+
+                    if (Math.Round(Math.Min(X1, X2), precision) <= Math.Round(xi, precision) &&
+                        Math.Round(xi, precision) <= Math.Round(Math.Max(X1, X2), precision) &&
+                        Math.Round(Math.Min(Y1, Y2), precision) <= Math.Round(yi, precision) &&
+                        Math.Round(yi, precision) <= Math.Round(Math.Max(Y1, Y2), precision) &&
+                        Math.Round(Math.Min(other.X1, other.X2), precision) <= Math.Round(xi, precision) &&
+                        Math.Round(xi, precision) <= Math.Round(Math.Max(other.X1, other.X2), precision) &&
+                        Math.Round(Math.Min(other.Y1, other.Y2), precision) <= Math.Round(yi, precision) &&
+                        Math.Round(yi, precision) <= Math.Round(Math.Max(other.Y1, other.Y2), precision))
+                    {
+                        return new PointF((float)xi, (float)yi);
+                    }
+                    else
+                    {
+                        return null;
+                    }
+                }
 
-                var a2 = other.Y2 - other.Y1;
-                var b2 = other.X1 - other.X2;
-                var c2 = other.X2 * other.Y1 - other.X1 * other.Y2;
 
-                var r1 = a2 * X1 + b2 * Y1 + c2;
-                var r2 = a2 * X2 + b2 * Y2 + c2;
+                //var a1 = Y2 - Y1;
+                //var b1 = X1 - X2;
+                //var c1 = X2 * Y1 - X1 * Y2;
 
-                if (r1 != 0 && r2 != 0 && Math.Sign(r1) == Math.Sign(r2))
-                {
-                    return (null);
-                }
+                //var r3 = a1 * other.X1 + b1 * other.Y1 + c1;
+                //var r4 = a1 * other.X2 + b1 * other.Y2 + c1;
 
-                var denom = a1 * b2 - a2 * b1;
+                //if (r3 != 0 && r4 != 0 && Math.Sign(r3) == Math.Sign(r4))
+                //{
+                //    return null;
+                //}
 
-                if (denom == 0)
-                {
-                    return null;
-                }
+                //var a2 = other.Y2 - other.Y1;
+                //var b2 = other.X1 - other.X2;
+                //var c2 = other.X2 * other.Y1 - other.X1 * other.Y2;
+
+                //var r1 = a2 * X1 + b2 * Y1 + c2;
+                //var r2 = a2 * X2 + b2 * Y2 + c2;
+
+                //if (r1 != 0 && r2 != 0 && Math.Sign(r1) == Math.Sign(r2))
+                //{
+                //    return (null);
+                //}
+
+                //var denom = a1 * b2 - a2 * b1;
+
+                //if (denom == 0)
+                //{
+                //    return null;
+                //}
 
-                var offset = denom < 0 ? -denom / 2 : denom / 2;
+                //var offset = denom < 0 ? -denom / 2 : denom / 2;
 
-                var num = b1 * c2 - b2 * c1;
-                var x = (num < 0 ? num - offset : num + offset) / denom;
+                //var num = b1 * c2 - b2 * c1;
+                //var x = (num < 0 ? num - offset : num + offset) / denom;
 
-                num = a2 * c1 - a1 * c2;
-                var y = (num < 0 ? num - offset : num + offset) / denom;
+                //num = a2 * c1 - a1 * c2;
+                //var y = (num < 0 ? num - offset : num + offset) / denom;
 
-                return new PointF(x, y);
+                //return new PointF(x, y);
             }
 
             private static void AddIfIntersect(LineF first, LineF second, ICollection<PointF> result)

Source/Painting/SvgRadialGradientServer.cs

 using System;
 using System.Diagnostics;
 using System.Drawing;
+using System.Collections.Generic;
 using System.Drawing.Drawing2D;
 using System.Linq;
 
@@ -95,6 +96,8 @@ namespace Svg
             Radius = new SvgUnit(SvgUnitType.Percentage, 50F);
         }
 
+        private object _lockObj = new Object();
+
         public override Brush GetBrush(SvgVisualElement renderingElement, SvgRenderer renderer, float opacity)
         {
             LoadStops(renderingElement);
@@ -102,20 +105,39 @@ namespace Svg
             try
             {
                 if (this.GradientUnits == SvgCoordinateUnits.ObjectBoundingBox) renderer.Boundable(renderingElement);
+                
+                // Calculate the path and transform it appropriately
                 var origin = renderer.Boundable().Location;
-                var centerPoint = CalculateCenterPoint(renderer, origin);
-                var focalPoint = CalculateFocalPoint(renderer, origin);
-
-                var specifiedRadius = CalculateRadius(renderer);
-                var effectiveRadius = CalculateEffectiveRadius(renderingElement, centerPoint, specifiedRadius);
-
-                var brush = new PathGradientBrush(CreateGraphicsPath(origin, centerPoint, effectiveRadius))
-                {
-                    InterpolationColors = CalculateColorBlend(renderer, opacity, specifiedRadius, effectiveRadius),
-                    CenterPoint = focalPoint
-                };
-
-                Debug.Assert(brush.Rectangle.Contains(renderingElement.Bounds), "Brush rectangle does not contain rendering element bounds!");
+                var center = new PointF(origin.X + CenterX.ToDeviceValue(renderer, UnitRenderingType.HorizontalOffset, this),
+                                         origin.Y + CenterY.ToDeviceValue(renderer, UnitRenderingType.VerticalOffset, this));
+                var specifiedRadius = Radius.ToDeviceValue(renderer, UnitRenderingType.Other, this);
+                var path = new GraphicsPath();
+                path.AddEllipse(
+                    origin.X + center.X - specifiedRadius, origin.Y + center.Y - specifiedRadius,
+                    specifiedRadius * 2, specifiedRadius * 2
+                );
+                path.Transform(EffectiveGradientTransform);
+
+
+                // Calculate any required scaling
+                var scale = CalcScale(renderingElement.Bounds, path);
+
+                // Get the color blend and any tweak to the scaling
+                var blend = CalculateColorBlend(renderer, opacity, scale, out scale);
+
+                // Transform the path based on the scaling
+                var gradBounds = path.GetBounds();
+                var transCenter = new PointF(gradBounds.Left + gradBounds.Width / 2, gradBounds.Top + gradBounds.Height / 2);
+                var scaleMat = new Matrix();
+                scaleMat.Translate(-1 * transCenter.X, -1 * transCenter.Y, MatrixOrder.Append);
+                scaleMat.Scale(scale, scale, MatrixOrder.Append);
+                scaleMat.Translate(transCenter.X, transCenter.Y, MatrixOrder.Append);
+                path.Transform(scaleMat);
+
+                // calculate the brush
+                var brush = new PathGradientBrush(path);
+                brush.CenterPoint = CalculateFocalPoint(renderer, origin);
+                brush.InterpolationColors = blend;
 
                 return brush;
             }
@@ -125,12 +147,38 @@ namespace Svg
             }
         }
 
-        private PointF CalculateCenterPoint(SvgRenderer renderer, PointF origin)
+        /// <summary>
+        /// Determine how much (approximately) the path must be scaled to contain the rectangle
+        /// </summary>
+        /// <param name="bounds">Bounds that the path must contain</param>
+        /// <param name="path">Path of the gradient</param>
+        /// <returns>Scale factor</returns>
+        /// <remarks>
+        /// This method continually transforms the rectangle (fewer points) until it is contained by the path
+        /// and returns the result of the search.  The scale factor is set to a constant 95%
+        /// </remarks>
+        private float CalcScale(RectangleF bounds, GraphicsPath path)
         {
-            var deviceCenterX = origin.X + CenterX.ToDeviceValue(renderer, UnitRenderingType.HorizontalOffset, this);
-            var deviceCenterY = origin.Y + CenterY.ToDeviceValue(renderer, UnitRenderingType.VerticalOffset, this);
-            var transformedCenterPoint = TransformPoint(new PointF(deviceCenterX, deviceCenterY));
-            return transformedCenterPoint;
+            var points = new PointF[] {
+                new PointF(bounds.Left, bounds.Top), 
+                new PointF(bounds.Right, bounds.Top), 
+                new PointF(bounds.Right, bounds.Bottom), 
+                new PointF(bounds.Left, bounds.Bottom) 
+            };
+            var pathBounds = path.GetBounds();
+            var pathCenter = new PointF(pathBounds.X + pathBounds.Width / 2, pathBounds.Y + pathBounds.Height / 2);
+            var transform = new Matrix();
+            transform.Translate(-1 * pathCenter.X, -1 * pathCenter.Y, MatrixOrder.Append);
+            transform.Scale(.95f, .95f, MatrixOrder.Append);
+            transform.Translate(pathCenter.X, pathCenter.Y, MatrixOrder.Append);
+
+            var boundsTest = RectangleF.Inflate(bounds, 0, 0);
+            while (!(path.IsVisible(points[0]) && path.IsVisible(points[1]) &&
+                     path.IsVisible(points[2]) && path.IsVisible(points[3])))
+            {
+                transform.TransformPoints(points);
+            }
+            return bounds.Height / (points[2].Y - points[1].Y);
         }
 
         private PointF CalculateFocalPoint(SvgRenderer renderer, PointF origin)
@@ -141,44 +189,6 @@ namespace Svg
             return transformedFocalPoint;
         }
 
-        private float CalculateRadius(SvgRenderer renderer)
-        {
-            var radius = Radius.ToDeviceValue(renderer, UnitRenderingType.Other, this);
-            var transformRadiusVector = TransformVector(new PointF(radius, 0));
-            var transformedRadius = CalculateLength(transformRadiusVector);
-            return transformedRadius;
-        }
-
-        private float CalculateEffectiveRadius(ISvgBoundable boundable, PointF centerPoint, float specifiedRadius)
-        {
-            if (SpreadMethod != SvgGradientSpreadMethod.Pad)
-            {
-                return specifiedRadius;
-            }
-
-            var topLeft = new PointF(boundable.Bounds.Left, boundable.Bounds.Top);
-            var topRight = new PointF(boundable.Bounds.Right, boundable.Bounds.Top);
-            var bottomRight = new PointF(boundable.Bounds.Right, boundable.Bounds.Bottom);
-            var bottomLeft = new PointF(boundable.Bounds.Left, boundable.Bounds.Bottom);
-
-            var effectiveRadius = (float)Math.Ceiling(
-                Math.Max(
-                    Math.Max(
-                        CalculateDistance(centerPoint, topLeft),
-                        CalculateDistance(centerPoint, topRight)
-                    ),
-                    Math.Max(
-                        CalculateDistance(centerPoint, bottomRight),
-                        CalculateDistance(centerPoint, bottomLeft)
-                    )
-                )
-            );
-
-            effectiveRadius = Math.Max(effectiveRadius, specifiedRadius);
-
-            return effectiveRadius;
-        }
-
         private static GraphicsPath CreateGraphicsPath(PointF origin, PointF centerPoint, float effectiveRadius)
         {
             var path = new GraphicsPath();
@@ -193,23 +203,66 @@ namespace Svg
             return path;
         }
 
-        private ColorBlend CalculateColorBlend(SvgRenderer renderer, float opacity, float specifiedRadius, float effectiveRadius)
+        private ColorBlend CalculateColorBlend(SvgRenderer renderer, float opacity, float scale, out float outScale)
         {
             var colorBlend = GetColorBlend(renderer, opacity, true);
+            float newScale;
+            List<float> pos;
+            List<Color> colors;
 
-            if (specifiedRadius >= effectiveRadius)
+            outScale = scale;
+            if (scale > 1)
             {
-                return colorBlend;
-            }
-
-            for (var i = 0; i < colorBlend.Positions.Length - 1; i++)
-            {
-                colorBlend.Positions[i] = 1 - (specifiedRadius / effectiveRadius) * (1 - colorBlend.Positions[i]);
+                switch (this.SpreadMethod)
+                {
+                    case SvgGradientSpreadMethod.Reflect:
+                        newScale = (float)Math.Ceiling(scale);
+                        pos = (from p in colorBlend.Positions select p / newScale).ToList();
+                        colors = colorBlend.Colors.ToList();
+
+                        for (var i = 1; i < newScale; i++)
+                        {
+                            if (i % 2 == 1)
+                            {
+                                pos.AddRange(from p in colorBlend.Positions.Reverse().Skip(1) select (1 - p + i) / newScale);
+                                colors.AddRange(colorBlend.Colors.Reverse().Skip(1));
+                            }
+                            else
+                            {
+                                pos.AddRange(from p in colorBlend.Positions.Skip(1) select (p + i) / newScale);
+                                colors.AddRange(colorBlend.Colors.Skip(1));
+                            }
+                        }
+
+                        colorBlend.Positions = pos.ToArray();
+                        colorBlend.Colors = colors.ToArray();
+                        outScale = newScale;
+                        break;
+                    case SvgGradientSpreadMethod.Repeat:
+                        newScale = (float)Math.Ceiling(scale);
+                        pos = (from p in colorBlend.Positions select p / newScale).ToList();
+                        colors = colorBlend.Colors.ToList();
+
+                        for (var i = 1; i < newScale; i++)
+                        {
+                            pos.AddRange(from p in colorBlend.Positions select (p <= 0 ? 0.001f : p) / newScale);
+                            colors.AddRange(colorBlend.Colors);
+                        }
+
+                        break;
+                    default:
+                        for (var i = 0; i < colorBlend.Positions.Length - 1; i++)
+                        {
+                            colorBlend.Positions[i] = 1 - (1 - colorBlend.Positions[i]) / scale;
+                        }
+
+                        colorBlend.Positions = new[] { 0F }.Concat(colorBlend.Positions).ToArray();
+                        colorBlend.Colors = new[] { colorBlend.Colors.First() }.Concat(colorBlend.Colors).ToArray();
+
+                        break;
+                }
             }
 
-            colorBlend.Positions = new[] { 0F }.Concat(colorBlend.Positions).ToArray();
-            colorBlend.Colors = new[] { colorBlend.Colors.First() }.Concat(colorBlend.Colors).ToArray();
-
             return colorBlend;
         }
 

Source/Svg.csproj

@@ -101,6 +101,7 @@
     <Compile Include="Clipping and Masking\SvgMask.cs" />
     <Compile Include="DataTypes\ISvgSupportsCoordinateUnits.cs" />
     <Compile Include="DataTypes\SvgTextDecoration.cs" />
+    <Compile Include="Filter Effects\ImageBuffer.cs" />
     <Compile Include="Painting\GenericBoundable.cs" />
     <Compile Include="SvgNodeReader.cs" />
     <Compile Include="Css\CssQuery.cs" />