CodeBrix.Imaging.Drawing.NoSkia.ApacheLicenseForever 1.0.252.351

CodeBrix.Imaging.Drawing

A stroke-based drawing, painting and highlighting library for .NET applications, built on SkiaSharp. CodeBrix.Imaging.Drawing captures pointer (mouse, pen, or touch) input as resolution-independent calibrated strokes on named, colored layers, renders them with translucent "highlighter" compositing over a background image — or over a transparent canvas above live content such as a webcam video feed — and exports finished drawings as PNG/JPEG images or CodeBrix.Imaging images. It works with any UI framework that can host a Skia drawing surface, including CodeBrix.Platform (all Skia heads), native WinUI 3, WPF, and .NET MAUI. CodeBrix.Imaging.Drawing is provided as a .NET 10 library and associated CodeBrix.Imaging.Drawing.ApacheLicenseForever NuGet package.

A companion package, CodeBrix.Imaging.Drawing.NoSkia.ApacheLicenseForever, is not yet published. It offers the identical drawing-session API with no native libraries at all, adding a fully managed 2D drawing engine (DrawingCanvas, DrawingBitmap, DrawingPaint, DrawingPath, gradients, pattern fills, blend modes, clipping, save-layers) in the CodeBrix.Imaging.Drawing.NoSkia namespace and a fully managed SVG renderer (DrawingSvg, in CodeBrix.Imaging.Drawing.NoSkia.Svg) that rasterizes an SVG document at any scale with explicit font registration, so output never depends on system fonts. The two packages are either/or alternatives — they compile the same drawing-session sources into the same namespaces — so an application references one or the other, never both.

CodeBrix.Imaging.Drawing supports applications and assemblies that target Microsoft .NET version 10.0 and later. Microsoft .NET version 10.0 is a Long-Term Supported (LTS) version of .NET, and was released on Nov 11, 2025; and will be actively supported by Microsoft until Nov 14, 2028. Please update your C#/.NET code and projects to the latest LTS version of Microsoft .NET.

Installation

dotnet add package CodeBrix.Imaging.Drawing.ApacheLicenseForever

Note that the NuGet package ID and the namespaces are different - there is no package named plain CodeBrix.Imaging.Drawing:

• NuGet package ID: CodeBrix.Imaging.Drawing.ApacheLicenseForever
• Assembly and primary namespace: CodeBrix.Imaging.Drawing - i.e. using CodeBrix.Imaging.Drawing; - which holds DrawingSession, the entry point
• Additional namespaces: CodeBrix.Imaging.Drawing.Models (DrawingLayer, Stroke and the other model types), CodeBrix.Imaging.Drawing.Shapes (the geometric primitives), CodeBrix.Imaging.Drawing.Rendering (DrawingRenderer, CanvasCalibration) and CodeBrix.Imaging.Drawing.Extensions (the color, geometry and image bridge extensions)

XML documentation (IntelliSense) ships alongside the assembly.

The package pulls in the following automatically; no version pinning is needed in the consuming project:

• SkiaSharp - the rendering engine
• CodeBrix.Imaging.ApacheLicenseForever - colors, sizes, image decoding and encoding, and the Image<Rgba32> export type

CodeBrix.Imaging.Drawing supports:

• Interactive stroke drawing driven by simple pointer events (PointerPressed / PointerMoved / PointerReleased) forwarded from any UI framework's canvas control
• Resolution-independent stroke storage in a calibrated logical space, so drawings survive window resizing, DPI changes, and orientation flips
• Named, colored drawing layers (for example Pain / Numbness / Tingling) with translucent highlighter compositing — overlapping strokes within a layer never double-darken
• Annotating photos and images of any aspect ratio: DrawingSession.CreateForImage(...) takes an explicit calibration size — or an explicit CalibrationSizing.DeriveFromBackgroundImage choice that computes it from the image — and the parameterless export methods produce the annotated image at its original resolution with no distortion
• Drawing over a background image (such as a black-and-white line diagram), over a solid fill, or over a fully transparent canvas above externally rendered content such as a live video frame
• Incremental rendering with per-layer bitmap caches, so live drawing stays fast at large stroke counts
• Programmatic drawing primitives — lines, arrows, circles, ellipses, rectangles, and polylines/polygons (outline or filled) — using plain coordinates and CodeBrix.Imaging colors, with no low-level graphics knowledge required; ideal for computer-vision-driven annotation of a live video feed
• Clear, per-layer clear, and undo-last-stroke operations (shapes and strokes share one undo history)
• Export to PNG or JPEG bytes, to an SKImage, or to a CodeBrix.Imaging Image<Rgba32> for further processing

Native assets: one package your application must add

The SkiaSharp native binaries do not arrive transitively. An application built on CodeBrix.Platform gets them from its platform head package; a plain .NET application adds the SkiaSharp native-asset package for each platform it runs on - for example, a Linux console or service app adds:

dotnet add package SkiaSharp.NativeAssets.Linux

Use the SkiaSharp.NativeAssets.macOS or SkiaSharp.NativeAssets.Win32 variant per platform. Without the matching package the project still compiles, and then fails at run time on the first drawing call with a native-library load error.

Sample Code

Drawing on a canvas with highlighter layers

using CodeBrix.Imaging;                 // Color, Size
using CodeBrix.Imaging.Drawing;         // DrawingSession
using CodeBrix.Imaging.Drawing.Models;  // DrawingLayer

var session = new DrawingSession();
session.SetBackgroundImage(File.ReadAllBytes("body_map.png"));
session.BackgroundFillColor = Color.White;

DrawingLayer pain = session.AddLayer("Pain", Color.FromRgb(255, 30, 230));
DrawingLayer numbness = session.AddLayer("Numbness", Color.FromRgb(30, 128, 204));
session.ActiveLayer = pain;

// Hook the session to your UI framework's canvas control:
session.RedrawRequested += (s, e) => canvasControl.Invalidate();
// In the control's PaintSurface handler:
//   session.Render(e.Surface, e.Info);
// In the control's pointer handlers (left button):
//   session.PointerPressed(point, viewSize); session.PointerMoved(point, viewSize); session.PointerReleased();

// Save the finished drawing:
byte[] png = session.ExportPng(new Size(1000, 1000));
File.WriteAllBytes("highlighted_body_map.png", png);

Annotating a photo (any aspect ratio)

using CodeBrix.Imaging;          // Color, Size
using CodeBrix.Imaging.Drawing;  // DrawingSession, CalibrationSizing

// You explicitly choose the calibrated drawing space: pass a size, or ask for it
// to be derived from the photo's aspect ratio
var session = DrawingSession.CreateForImage(
    File.ReadAllBytes("car_photo.jpg"),
    CalibrationSizing.DeriveFromBackgroundImage);
session.AddLayer("Damage", Color.Red);

// ...wire pointer events and PaintSurface as above, draw on the photo...

// Exports at the photo's original resolution, never distorted
File.WriteAllBytes("car_photo_annotated.png", session.ExportPng());

The samples/PainDiagram folder of this repository contains a complete reference application that runs on every CodeBrix.Platform Skia head (Windows Win32 and WPF-hosted, Linux X11 / Wayland / framebuffer, macOS) plus native WinUI 3 and WPF heads, all sharing one view model.

Documentation

The NuGet package includes AGENT-README.txt, a complete API reference and usage guide written for AI coding agents - point your agent at that file when it is writing code against this library.

Additional sample code and usage examples are available in the CodeBrix.Imaging.Drawing.Tests project: https://github.com/ellisnet/CodeBrix.Imaging.Drawing/tree/main/tests/CodeBrix.Imaging.Drawing.Tests

License

CodeBrix.Imaging.Drawing is licensed under the Apache License 2.0 - see the LICENSE file.

For licensing and provenance information about the open source code included in this package, see THIRD-PARTY-NOTICES.txt.