This repository contains a refactored version of ClosedXML that introduces a pluggable graphics engine architecture. This change removes the hard dependency on SixLabors.Fonts from the core library, making it lightweight and more flexible for different environments.

• Pluggable Architecture: The IXLGraphicEngine interface has been extracted, allowing different implementations for text measurement and image handling.
• Dependency Removal: The core ClosedXML package no longer depends on SixLabors.Fonts.
• Default Implementation: An embedded ApproximateGraphicEngine is used by default. It uses precomputed metrics for the Carlito font and requires no external dependencies.
• New Packages:
  • ClosedXML.Graphic.SixLabors: The original implementation using SixLabors.Fonts.
  • ClosedXML.Graphic.Skia: An implementation using SkiaSharp.
  • ClosedXML.Graphic.GDI: An implementation using System.Drawing.Common (GDI+), utilizing installed system fonts.

By default, ClosedXML uses the ApproximateGraphicEngine. This works out-of-the-box without any additional configuration or packages.

using var workbook = new XLWorkbook();
// Uses ApproximateGraphicEngine

To use the original accurate text measurement:

1. Install the ClosedXML.Graphic.SixLabors package.
2. Configure the engine at startup or per-workbook.

// Global configuration
LoadOptions.DefaultGraphicEngine = new SixLaborsGraphicEngine();

// Or per-workbook
var options = new LoadOptions
{
    GraphicEngine = new SixLaborsGraphicEngine()
};
using var workbook = new XLWorkbook(options);

To use SkiaSharp for rendering metrics:

1. Install the ClosedXML.Graphic.Skia package.
2. Configure the engine.

LoadOptions.DefaultGraphicEngine = new SkiaGraphicEngine();

To use installed system fonts on Windows (or configured GDI+ environments):

1. Install the ClosedXML.Graphic.GDI package.
2. Configure the engine.

LoadOptions.DefaultGraphicEngine = new GdiGraphicEngine();

Same as ClosedXML (MIT).