Svg.Skia

Svg.Skia is an SVG rendering library.

About

Svg.Skia can be used as a .NET library or as a CLI application to render SVG files based on a static SVG Full 1.1 subset to raster images or to a backend's canvas.

The Svg.Skia is using SVG library to load Svg object model.

The Svg.Skia library is implemented using the SkiaSharp rendering backend that aims to be on par or more complete than the original System.Drawing implementation and more performant and cross-platform.

The Svg.Skia can be used in same way as the SkiaSharp.Extended.Svg (load svg files as SKPicture).

The Svg library has a more complete implementation of the Svg document model than SkiaSharp.Extended.Svg and the Svg.Skia renderer will provide more complete rendering subsystem implementation.

NuGet

Svg.Skia is delivered as a NuGet package.

You can find the packages here NuGet and install the package like this:

Install-Package Svg.Skia

or by using nightly build feed:

• Add https://www.myget.org/F/svgskia-nightly/api/v2 to your package sources
• Alternative nightly build feed https://pkgs.dev.azure.com/wieslawsoltes/GitHub/_packaging/Nightly/nuget/v3/index.json
• Update your package using Svg.Skia feed

and install the package like this:

Install-Package Svg.Skia -Pre

Usage

Library

Install Package

dotnet add package Svg.Skia

Install-Package Svg.Skia

Draw on Canvas

using SkiaSharp;
using Svg.Skia;

var svg = new SKSvg();

svg.Load("image.svg");

SKCanvas canvas = ...
canvas.DrawPicture(svg.Picture);

Save as Png

using SkiaSharp;
using Svg.Skia;

using (var svg = new SKSvg())
{
    if (svg.Load("image.svg") is { })
    {
        svg.Save("image.png", SKEncodedImageFormat.Png, 100, 1f, 1f);
    }
}

using System.IO;
using SkiaSharp;
using Svg.Skia;

using (var svg = new SKSvg())
{
    if (svg.Load("image.svg") is { })
    {
        using (var stream = File.OpenWrite("image.png"))
        {
            svg.Picture.ToImage(stream, SKColors.Empty, SKEncodedImageFormat.Png, 100, 1f, 1f);
        }
    }
}

using SkiaSharp;
using Svg.Skia;

using (var svg = new SKSvg())
{
    if (svg.Load("image.svgz") is { })
    {
        svg.Save("image.png", SKEncodedImageFormat.Png, 100, 1f, 1f);
    }
}

using System.IO;
using SkiaSharp;
using Svg.Skia;

using (var svg = new SKSvg())
{
    if (svg.Load("image.svgz") is { })
    {
        using (var stream = File.OpenWrite("image.png"))
        {
            svg.Picture.ToImage(stream, SKColors.Empty, SKEncodedImageFormat.Png, 100, 1f, 1f);
        }
    }
}

Save as Pdf

using SkiaSharp;
using Svg.Skia;

using (var svg = new SKSvg())
{
    if (svg.Load("image.svg") is { })
    {
        svg.Picture.ToPdf("image.pdf", SKColors.Empty, 1f, 1f);
    }
}

Save as Xps

using SkiaSharp;
using Svg.Skia;

using (var svg = new SKSvg())
{
    if (svg.Load("image.svg") is { })
    {
        svg.Picture.ToXps("image.xps", SKColors.Empty, 1f, 1f);
    }
}

Hit Testing

SKSvg

The SKSvg class provides helpers for retrieving elements or drawables at a given point. The hit-testing methods expect coordinates in picture space:

using SkiaSharp;
using Svg.Skia;

var svg = new SKSvg();
if (svg.Load("image.svg") is { })
{
    var element = svg.HitTestElements(new SKPoint(10, 10)).FirstOrDefault();
    if (element is { })
    {
        Console.WriteLine(element.ID);
    }
}

When drawing on a transformed canvas you can convert canvas coordinates to picture coordinates using TryGetPicturePoint and then use the hit-testing methods.

Svg control

The Svg Avalonia control exposes a HitTestElements method that accepts a point in control coordinates and returns the matching SVG elements:

var hits = svgControl.HitTestElements(new Point(x, y));

Avalonia

Install Package

dotnet add package Svg.Controls.Skia.Avalonia

Install-Package Svg.Controls.Skia.Avalonia

Svg control

<Svg Path="/Assets/__AJ_Digital_Camera.svg"/>

Image control

<Image Source="{SvgImage /Assets/__AJ_Digital_Camera.svg}"/>

Background

<Border Width="100"
        Height="100"
        Background="{SvgImage /Assets/__AJ_Digital_Camera.svg}" />

CSS styling

<Svg Path="/Assets/__tiger.svg" 
     Css=".Black { fill: #FF0000; }"  />

<Style Selector="Svg">
  <Setter Property="(Svg.Css)" Value=".Black { fill: #FF0000; }" />
</Style>

<SvgSource x:Key="TigerIcon"
           Path="/Assets/__tiger.svg"
           Css=".Black { fill: #FF0000; }" />

<Image>
  <Image.Source>
    <SvgImage Source="{DynamicResource TigerIcon}" />
  </Image.Source>
</Image>

<Image>
  <Image.Source>
    <SvgImage Source="/Assets/__tiger.svg" Css=".Black { fill: #FF0000; }" />
  </Image.Source>
</Image>

SvgResourceExtension Markup Extension

The former SvgBrush markup extension has been renamed to SvgResourceExtension. In XAML you can use the short {SvgResource ...} syntax to paint any brush property directly:

<Border CornerRadius="12"
        Background="{SvgResource /Assets/__tiger.svg}" />

To reuse the brush across your view, declare it in resources (the markup extension type named SvgResourceExtension still trims to SvgResource when used in XAML):

<UserControl xmlns="https://github.com/avaloniaui"
             xmlns:svg="clr-namespace:Avalonia.Svg.Skia;assembly=Svg.Controls.Skia.Avalonia">
    <UserControl.Resources>
        <svg:SvgResource x:Key="TigerBrush"
                         Stretch="UniformToFill"
                         AlignmentX="Center"
                         AlignmentY="Center"
                         TileMode="Tile"
                         DestinationRect="0,0,1,1"
                         Opacity="0.85">/Assets/__tiger.svg</svg:SvgResource>
    </UserControl.Resources>

    <Border Background="{DynamicResource TigerBrush}" />
</UserControl>

The optional properties mirror those on VisualBrush, so you can tweak layout, tiling, opacity, and transforms directly in XAML while the control takes care of loading and rendering the SVG content.

When you need the brush from code-behind, the extension now exposes a ToBrush(IServiceProvider? serviceProvider = null) helper and supports implicit conversion to Brush, which can be assigned to any IBrush property:

// Resolve relative paths by providing BaseUri when running outside of XAML.
var brush = new SvgResourceExtension("avares://MyAssembly/Assets/Icon.svg")
{
    BaseUri = new Uri("avares://MyAssembly/")
}.ToBrush();

// Or rely on the implicit conversion to Brush/IBrush.
IBrush background = new SvgResourceExtension("avares://MyAssembly/Assets/Icon.svg");

// When you already have an SvgImage instance, create a brush directly.
var svgImage = new SvgImage
{
    Source = SvgSource.Load("avares://MyAssembly/Assets/Icon.svg", baseUri: null)
};
var fromImage = SvgResourceExtension.CreateBrush(
    svgImage,
    stretch: Stretch.Uniform,
    alignmentX: AlignmentX.Center,
    alignmentY: AlignmentY.Center);

// Or skip creating the markup extension entirely and build a brush from the SVG path in one call.
var fromPath = SvgResourceExtension.CreateBrush(
    "avares://MyAssembly/Assets/Icon.svg",
    stretch: Stretch.Fill,
    alignmentX: AlignmentX.Right,
    alignmentY: AlignmentY.Bottom);

The Skia-backed controls also accept optional css and currentCss arguments on the static helper so you can apply styles while creating the brush from code.

Avalonia Previewer

To make controls work with Avalonia Previewer please add the following lines to BuildAvaloniaApp() method:

GC.KeepAlive(typeof(SvgImageExtension).Assembly);
GC.KeepAlive(typeof(Svg.Controls.Skia.Avalonia.Svg).Assembly);

The BuildAvaloniaApp() should look similar to this:

public static AppBuilder BuildAvaloniaApp()
{
    GC.KeepAlive(typeof(SvgImageExtension).Assembly);
    GC.KeepAlive(typeof(Svg.Controls.Skia.Avalonia.Svg).Assembly);
    return AppBuilder.Configure<App>()
        .UsePlatformDetect()
        .LogToTrace();
}

This is known issue as previewer not always loads all dependencies, especially custom controls in Avalonia xmlns, other solution would be to add xmlns prefix to control with provided assembly path.

Avalonia SkiaSharp Controls

Install Package

dotnet add package Skia.Controls.Avalonia

Install-Package Skia.Controls.Avalonia

Canvas

Usage:

<SKCanvasControl Name="CanvasControl" />

CanvasControl.Draw += (_, e) =>
{
    e.Canvas.DrawRect(SKRect.Create(0f, 0f, 100f, 100f), new SKPaint { Color = SKColors.Aqua });
};

Command-line tool

dotnet tool install -g Svg.Skia.Converter

Svg.Skia.Converter:
  Converts a svg file to an encoded bitmap image.

Usage:
  Svg.Skia.Converter [options]

Options:
  -f, --inputFiles <inputfiles>              The relative or absolute path to the input files
  -d, --inputDirectory <inputdirectory>      The relative or absolute path to the input directory
  -o, --outputDirectory <outputdirectory>    The relative or absolute path to the output directory
  --outputFiles <outputfiles>                The relative or absolute path to the output files
  -p, --pattern <pattern>                    The search string to match against the names of files in the input directory
  --format <format>                          The output image format
  -q, --quality <quality>                    The output image quality
  -b, --background <background>              The output image background
  -s, --scale <scale>                        The output image horizontal and vertical scaling factor
  --scaleX, -sx <scalex>                     The output image horizontal scaling factor
  --scaleY, -sy <scaley>                     The output image vertical scaling factor
  --systemLanguage <systemlanguage>          The system language name as defined in BCP 47
  --quiet                                    Set verbosity level to quiet
  -c, --load-config <load-config>            The relative or absolute path to the config file
  --save-config <save-config>                The relative or absolute path to the config file
  --version                                  Show version information
  -?, -h, --help                             Show help and usage information

Supported formats: png, jpg, jpeg, webp, pdf, xps

SVG to C# Compiler

About

SVGC compiles SVG drawing markup to C# using SkiaSharp as rendering engine. SVGC can be also used as codegen for upcoming C# 9 Source Generator feature.

Source Generator Usage

Add NuGet package reference to your csproj.

<PropertyGroup>
  <OutputType>Exe</OutputType>
  <TargetFramework>net6.0</TargetFramework>
  <LangVersion>latest</LangVersion>
</PropertyGroup>

<ItemGroup>
  <PackageReference Include="Svg.SourceGenerator.Skia" Version="0.5.0" />
</ItemGroup>

Include svg assets file in your csproj.

<ItemGroup>
  <AdditionalFiles Include="Assets/Sample.svg" NamespaceName="Assets" ClassName="Sample" />
</ItemGroup>

Use generated SKPicture using static Picture property from Sample class.

using SkiaSharp;
using Assets;

public void Draw(SKCanvas canvas)
{
    canvas.DrawPicture(Sample.Picture);
}

Avalonia Usage

csproj

<ItemGroup>
  <AdditionalFiles Include="Assets/__tiger.svg" NamespaceName="AvaloniaSample" ClassName="Tiger" />
</ItemGroup>

<ItemGroup>
  <PackageReference Include="Svg.SourceGenerator.Skia" Version="0.5.0" />
  <PackageReference Include="Skia.Controls.Avalonia" Version="0.5.0" />
</ItemGroup>

xaml

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:AvaloniaSample;assembly=AvaloniaSample"
        xmlns:skp="clr-namespace:Skia.Controls.Avalonia;assembly=Skia.Controls.Avalonia"
        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
        Width="900" Height="650" WindowStartupLocation="CenterScreen"
        x:Class="AvaloniaSample.MainWindow"
        Title="AvaloniaSample">
    <Window.Resources>
        <skp:SKPictureImage x:Key="TigeImage" Source="{x:Static local:Tiger.Picture}" />
    </Window.Resources>
    <Grid>
        <Image Source="{StaticResource TigeImage}" />
    </Grid>
</Window>

svgc Usage

svgc:
  Converts a svg file to a C# code.

Usage:
  svgc [options]

Options:
  -i, --inputFile <inputfile>      The relative or absolute path to the input file [default: ]
  -o, --outputFile <outputfile>    The relative or absolute path to the output file [default: ]
  -j, --jsonFile <jsonfile>        The relative or absolute path to the json file [default: ]
  -n, --namespace <namespace>      The generated C# namespace name [default: Svg]
  -c, --class <class>              The generated C# class name [default: Generated]
  --version                        Show version information
  -?, -h, --help                   Show help and usage information

Json File Format

[
    { "InputFile":"file1.svg", "OutputFile":"file1.svg.cs", "Class":"ClassName1", "Namespace":"NamespaceName" },
    { "InputFile":"file2.svg", "OutputFile":"file2.svg.cs", "Class":"ClassName2", "Namespace":"NamespaceName" }
]

Links

• Source Generators Cookbook
• Source Generators
• Source Generators Samples
• Introducing C# Source Generators

Build

To build the projects you need to install .NET 5.0 version SDK 5.0.100.

git clone git@github.com:wieslawsoltes/Svg.Skia.git
cd Svg.Skia
git submodule update --init --recursive
dotnet build -c Release

Publish Managed

cd ./src/Svg.Skia.Converter
dotnet publish -c Release -f net6.0 -r win7-x64 /p:PublishTrimmed=True /p:PublishReadyToRun=True -o Svg.Skia.Converter_net6.0_win7-x64

cd ./src/Svg.Skia.Converter
dotnet publish -c Release -f net6.0 -r ubuntu.14.04-x64 /p:PublishTrimmed=True /p:PublishReadyToRun=True -o Svg.Skia.Converter_net6.0_ubuntu.14.04-x64

cd ./src/Svg.Skia.Converter
dotnet publish -c Release -f net6.0 -r osx.10.12-x64 /p:PublishTrimmed=True /p:PublishReadyToRun=True -o Svg.Skia.Converter_net6.0_osx.10.12-x64

cd ./src/Svg.Skia.Converter
dotnet publish -c Release -f net6.0 -r debian.8-x64 /p:PublishTrimmed=True /p:PublishReadyToRun=True -o Svg.Skia.Converter_net6.0_debian.8-x64

cd ./src/SvgToPng
dotnet publish -c Release -f net6.0 -r win7-x64 -o SvgToPng_net6.0_win7-x64

cd ./src/SvgXml.Diagnostics
dotnet publish -c Release -f net6.0 -r win7-x64 -o SvgXml.Diagnostics_net6.0_win7-x64

Publish Native

cd ./src/Svg.Skia.Converter
dotnet publish -c Release -f net6.0 -r win-x64 -o Svg.Skia.Converter_net6.0_win-x64

cd ./src/Svg.Skia.Converter
dotnet publish -c Release -f net6.0 -r linux-x64 -o Svg.Skia.Converter_net6.0_linux-x64

cd ./src/Svg.Skia.Converter
dotnet publish -c Release -f net6.0 -r osx-x64 -o Svg.Skia.Converter_net6.0_osx-x64

Externals

The Svg.Skia library is using code from the https://github.com/vvvv/SVG

License

Parts of Svg.Skia source code are adapted from the https://github.com/vvvv/SVG

Svg.Skia is licensed under the MIT license.