Skia-MonoGame Rendering

This library allows a MonoGame application to use SkiaSharp's GPU rendering without interfering with regular MonoGame rendering. It comes with a sample application. It currently requires a DesktopGL rendering backend (will not work on DirectX), and it will not work on consoles without significant work, although it is technically possible. However, it will work fine for games targeting destkop platforms.

Requirements

Visual Studio 2022 and .NET 6.

Setup

Reference the library and place the next lines of code on your MonoGame project (see below for detailed instructions).

In your game file (such as Game1.cs) in the Initialize() method:

SkiaGlManager.Initialize(GraphicsDevice);

And also in the Draw() method before base.Draw():

SkiaRenderer.Draw();

Implement ISkiaRenderable on your game classes

These are the required ISkiaRenderable members:

TargetWidth: Width of the output texture.

TargetHeight: Height of the output texture.

TargetColorFormat: Format of the output texture.

ShouldRender: Whether the texture is being updated. Set this to false when you don't need to update your texture.

DrawToSurface(SKSurface surface): This will be called if ShouldRender is true. This is the place to apply your SkiaSharp drawing commands to the argument SKSurface.

NotifyDrawnTexture(Texture2D texture): The resulting texture will be delivered here. It's a regular MonoGame texture ready to be painted to the screen.

Add your ISkiaRenderable's to the rendering list

To add a renderable:

SkiaRenderer.AddRenderable(renderable);

To remove it:

SkiaRenderer.RemoveRenderable(renderable);

An exception will be thrown whether you try to add an already present renderable or you try to remove a renderable which hasn't been added. Be careful.

Example usage

There's a project called Sample already set up with everything needed but if you wish to set it up yourself, these are the steps:

First, you must clone the repository. At the time of this writing there are no prebuilt binaries, or NuGet packages, so you must compile the library yourself. The easiest way is to link this in your game project:

Clone the project locally
Add SkiaMonoGameRendering project to your solution (.sln).
Add a SkiaMonoGameRendering project reference to your MonoGame project (.csproj).
Paste SkiaEntity.cs into your MonoGame project root folder.
Change the namespace of the file you just pasted to match your project namespace, so it can be easily found.
Next you'll need to change your game class. This file is called Game1.cs by default in the MonoGame sample. You can follow this one as an example Game1.cs or follow the next steps:

You need to add this at class scope:

        private SkiaEntity _entity;

        void DrawSkiaEntity()
        {
            var destinationRectangle = new Rectangle(0, 0, _entity.Texture.Width, _entity.Texture.Height);

            _spriteBatch.Begin(SpriteSortMode.Deferred);
            _spriteBatch.Draw(_entity.Texture, destinationRectangle, Color.White);
            _spriteBatch.End();
        }

Your Initialize method should look like this:

        protected override void Initialize()
        {
            SkiaGlManager.Initialize(GraphicsDevice);

            _entity = new SkiaEntity();
            _entity.Initialize();

            base.Initialize();
        }

And your Draw method should look like this:

        protected override void Draw(GameTime gameTime)
        {
            SkiaRenderer.Draw();

            GraphicsDevice.Clear(Color.Black);

            DrawSkiaEntity();

            base.Draw(gameTime);
        }

Run your project and you're done. One beautiful big red circle rendered by Skia should show up:

Using Skia Sharp

The example SkiaEntity.cs file renders a large, anti-aliased red circle. Skia rendering is performed by calling a skia canvas to perform rendering. For example, the following code performs the actual circle rendering:

surface.Canvas.DrawCircle(Radius, Radius, Radius, _paint);

The Skia canvas can be used to render lots of types of graphics, and is especially useful for rendering anti-aliased vector art.

For more information on using SkiaSharp, see the SkiaSharp documentation:

https://learn.microsoft.com/en-us/previous-versions/xamarin/xamarin-forms/user-interface/graphics/skiasharp/basics/

vchelaru / SkiaMonoGameRendering