Building SkiaSharp

This guide covers building SkiaSharp on Windows and macOS.

Table of Contents

• Prerequisites
• Preparation
• Managed-Only Building
  • Dependencies
  • Preparation
  • Making Changes
  • Building
• Native Building
  • Dependencies
• Generating Documentation

Prerequisites

Before building SkiaSharp, ensure you have:

• .NET 8 SDK - The repository uses global.json to pin the SDK version
• MAUI workload - Required for mobile platform targets:
  bashCopy

  dotnet workload install maui
  

• Cake .NET Tool - For running build scripts:
  bashCopy

  dotnet tool install -g cake.tool
  

Preparation

Building a complete SkiaSharp is actually pretty simple, you just need to install a few dependencies.

To get started with any type of development, you will have to fork and then clone SkiaSharp. If you are not going to be making changes, you can clone the main repository:

> git clone https://github.com/mono/SkiaSharp

Once the source is on your machine, you can get started with building. There are a few ways in which to get started, depending on what you are going to do.

Managed-Only Building

In many cases, you just want to fix a bug in the managed code. If this is the case, you can just download the native bits from CI, and then work from there.

Dependencies

All Platforms:

• .NET 8 SDK - Pinned via global.json
• MAUI workload - dotnet workload install maui
• Cake .NET Tool - dotnet tool install -g cake.tool

Windows Dependencies:

• Windows 10/11
• Visual Studio 2022+
  • .NET desktop development
  • .NET Multi-platform App UI development (MAUI)
  • Universal Windows Platform development
• Windows 10 SDK (latest)

macOS Dependencies:

• macOS 12+ (Monterey or later)
• Xcode (latest stable)
• Command Line Tools: xcode-select --install

Preparation

The latest master build bits can be downloaded by running the externals-download target:

> dotnet cake --target=externals-download

If you need a specific build, you can specify the commit SHA from the git history:

> dotnet cake --target=externals-download --gitSha=<git-sha>

If you want the latest from a specific branch, you can also pass the branch name:

> dotnet cake --target=externals-download --gitBranch=<git-branch>

Making Changes

Once that is complete, you should be able to now start working on some code. You can open the source/SkiaSharpSource.sln solution (or one of the platform variants) and start making changes. If you are going to be working with unit tests, or don't need to work on all the platform projects, you can open the tests/SkiaSharp.Desktop.Tests/SkiaSharp.Desktop.Tests.sln solution.

The SkiaSharpSource.sln solution is primarily for working with platform-specific bits, and then you can compile to make sure everything is working. The SkiaSharp.Desktop.Tests.sln solution is for testing that changes to the API are still working as expected.

Building

Once you are finished making changes, you can run the tests target and make sure that the tests will pass on CI. There is also the samples and nuget targets. By adding the --skipExternals=all argument, you can let the bootstrapper know that it should not build any native bits, but rather use the bits that were downloaded.

> dotnet cake --target=everything --skipExternals=all

Native Building

Dependencies

In addition to a few extra dependencies, the Managed-Only build dependencies are still required.

Windows Dependencies:

• Managed-Only build dependencies
• Python 3
  • Make sure the path to python is in the PATH environment variable
• Visual Studio 2022+
  • Desktop development with C++
    • Windows 10/11 SDK (latest)
    • MSVC v143+ C++ build tools
  • Individual components
    • C++ compilers and libraries for ARM64
    • Android NDK (via Visual Studio Installer or manually)
      • Make sure the path to the root is in the ANDROID_NDK_ROOT or ANDROID_NDK_HOME environment variables
• OpenJDK 17+
• Clang/LLVM
  • Run .\scripts\install-llvm.ps1
  • Set LLVM_HOME to the path of the install

macOS Dependencies:

• Managed-Only build dependencies
• Xcode Command Line Tools
• Python 3

Linux Dependencies:

• Python 3
• Clang 14+
• Make
• OpenJDK 17+

Building Native Libraries

Build native libraries for specific platforms using Cake targets:

# macOS (Apple Silicon)
dotnet cake --target=externals-macos --arch=arm64

# macOS (Intel)
dotnet cake --target=externals-macos --arch=x64

# iOS (device)
dotnet cake --target=externals-ios

# iOS Simulator
dotnet cake --target=externals-ios-simulator --arch=arm64

# Android (ARM64)
dotnet cake --target=externals-android --arch=arm64

# Android (x86_64 for emulator)
dotnet cake --target=externals-android --arch=x64

# Windows (x64)
dotnet cake --target=externals-windows --arch=x64

# Linux (requires Docker)
dotnet cake --target=externals-linux --arch=x64

Tip: Native builds can take 10-30 minutes depending on your machine. Only build for platforms you need to test.

Generating Documentation

dotnet cake --target=docs-download-output [--gitSha=<git-sha> | --gitBranch=<git-branch>]
dotnet cake --target=update-docs