DRIT.Drawing 26.7.874

DRIT.Drawing

Pure-Managed 2D Graphics Library for .NET

System.Drawing.Common Replacement with Vector SVG, Metafile, and APNG Support

DRIT.Drawing is a pure-managed, cross-platform 2D graphics library for .NET that provides a direct replacement for System.Drawing.Common. It offers an intuitive API for drawing bitmap images, geometric shapes, and applying graphic transformations without relying on any third-party native libraries — and captures any drawing as true vector SVG or EMF/WMF metafile output.

Key Benefits

• Zero native dependencies – pure managed C# implementation, no System.Drawing.Common required
• Consistent rendering results across Windows, Linux, macOS, and Azure
• Seamless migration path from System.Drawing.Common
• Vector-first architecture – draw to true vector SVG or record EMF/WMF, not just raster
• Built-in font support with comprehensive TrueType/OpenType/CFF/Type1/WOFF/WOFF2 parsing
• Integrated WMF/EMF/EMF+ metafile support for reading and writing vector graphics
• Full Unicode bidirectional text (UAX #9), font fallback, rich text runs, and text-on-path
• Animated PNG (APNG) read/write through the standard multi-frame API

Cross-Platform Graphics Library

DRIT.Drawing supports 32-bit and 64-bit systems across multiple platforms:

• Operating Systems: Windows, Linux, macOS, Azure
• Frameworks: .NET Standard 2.0, .NET 6.0+
• Environments: ASP.NET Core, Blazor WebAssembly, Console applications

Features

Geometric Drawing API

Draw lines, shapes, rectangles, polygons, arcs, and Bezier curves with a cross-platform C# API:

• Graphics.DrawLine, DrawRectangle, DrawEllipse, DrawPolygon
• Graphics.DrawArc, DrawBezier, DrawCurve
• GraphicsPath for complex shape construction
• Region for clipping and hit-testing

Transformations Support

Apply different transformations to 2D objects:

• Graphics.TranslateTransform, RotateTransform, ScaleTransform
• Matrix class for custom transformations
• Graphics.Transform property for coordinate system changes

Drawing Tools

Working with Pens

• Set pen width and color
• Line join styles (miter, bevel, round)
• Dash patterns and line caps

Working with Brushes

• SolidBrush – fill with solid colors
• LinearGradientBrush – create gradient fills
• PathGradientBrush – complex gradient patterns
• HatchBrush – patterned fills
• TextureBrush – image-based fills

Image Rendering

• Antialiasing: 4× MSAA with per-edge coverage for smooth edges
• Clipping: Define clip regions with Graphics.SetClip
• Alpha Blending: Transparency support for layered compositions
• Interpolation: Nearest-neighbor, bilinear, and bicubic image scaling
• ImageAttributes: Color matrix, gamma, color key, remap table, threshold

Working with Text and Fonts

• DrawString for text rendering with full font support
• Built-in TrueType, OpenType, CFF, Type1, WOFF/WOFF2 font loading
• Font metrics: ascender, descender, line gap, units per EM
• Glyph outline rendering with IGlyphOutlinePainter
• Text hinting and anti-aliasing options
• Font family and style support

Integrated Font Capabilities

DRIT.Drawing includes a comprehensive font engine that provides text measurement and rendering without any external dependencies:

• Font Loading: Load fonts from files or byte arrays in TTF, OTF, CFF, Type1, WOFF, and WOFF2 formats
• Font Metrics: Access ascender, descender, line gap, and units-per-EM values for precise text layout
• Glyph Access: Query glyph bounding boxes and advance widths for accurate text measurement
• Glyph Rendering: Use IGlyphOutlinePainter to render glyph outlines with custom implementations
• Font Collections: Support for TTC (TrueType Collection) files with multiple fonts
• Font Subsetting: Create optimized font subsets containing only required glyphs

Bidirectional Text (UAX #9)

• Full Unicode Bidirectional Algorithm — RTL scripts (Arabic, Hebrew, …) and mixed-direction text
• StringFormatFlags.DirectionRightToLeft sets the paragraph embedding direction
• Mirroring of bracket/punctuation characters in RTL runs
• Enabled by default on existing DrawString (matches GDI+ behavior)

Font Fallback

• Automatic glyph substitution from a fallback font chain when the primary font lacks a glyph
• StringFormatFlags.NoFontFallback opts out (matches GDI+ behavior)
• Curated per-OS default chain (Segoe UI → Segoe UI Symbol → Segoe UI Emoji on Windows; DejaVu Sans → Noto Sans on Linux)
• Custom FontFallbackChain configurable per Graphics surface

Rich Text Runs

• DrawRichText / MeasureRichText / AddRichText for mixed fonts, sizes, styles, and brushes in a single layout
• RichTextOptions + RichTextRun describe per-range overrides
• Word wrapping across run boundaries; shared baseline for mixed-size runs

Text on Path

• DrawStringOnPath / AddStringOnPath render text along an arbitrary vector baseline
• Each glyph is positioned and rotated tangent to the path
• TextOnPathOptions controls start offset, perpendicular offset, alignment, and overflow

Vector Graphics (SVG + Vector Domain Model)

DRIT.Drawing is vector-first: any drawing performed through a Graphics surface can be captured as true vector output via a format-agnostic VectorScene domain model.

• RecordingGraphics – a Graphics surface that records drawing commands instead of rasterizing; same public API as Graphics
• SvgImage – a vector Image subclass; load/save SVG, rasterize to Bitmap, or convert to EMF/WMF
• SVG Writer – VectorScene → SVG with <path>, <linearGradient>/<radialGradient>, <pattern>, <clipPath>, <text> (path or text mode), and embedded <image> elements
• SVG Reader – SVG → VectorScene via a streaming XmlReader-based parser; tolerant of malformed input
• EMF/WMF Bridge – bidirectional transcoding between VectorScene and metafile records
• EMF/WMF Recording – capture any Graphics drawing as EMF/WMF (previously playback-only)
• Conversions – Graphics ↔ SVG ↔ EMF/WMF ↔ Bitmap, all through the single VectorScene pivot

Metafile Support (WMF/EMF/EMF+)

DRIT.Drawing includes integrated metafile support for Windows Metafile (WMF), Enhanced Metafile (EMF), and EMF+ formats:

• Metafile Reading: Parse WMF, EMF, and EMF+ metafiles with full record support
• Metafile Writing: Create and save metafiles in WMF, EMF, and EMF+ formats
• Record Types: Support for all standard WMF, EMF, and EMF+ record types
• Placeable Metafiles: Read and write placeable WMF headers for device-independent rendering
• Playback Integration: Render metafiles directly to Graphics objects for display or conversion

Supported File Formats

Installation

1. Install via NuGet

• Open Microsoft Visual Studio and the NuGet package manager
• Search for "DRIT.Drawing"
• Click Install to download and reference it in your project

2. Install via Package Manager Console

Install-Package DRIT.Drawing

3. Install via .NET CLI

dotnet add package DRIT.Drawing

Code Examples

Create a Bitmap and Draw Shapes

// Create a bitmap object
using var bitmap = new Bitmap(1000, 800);

// Initialize a Graphics object
using var graphics = Graphics.FromImage(bitmap);

// Define a pen with color and width
using var pen = new Pen(Color.Blue, 2);

// Draw a rectangle
graphics.DrawRectangle(pen, new Rectangle(100, 100, 300, 200));

// Draw an ellipse
graphics.DrawEllipse(pen, new Rectangle(500, 100, 300, 200));

// Save the image as PNG
bitmap.Save("output_shapes.png");

Draw Text with Anti-Aliasing

// Create a bitmap object
using var bitmap = new Bitmap(1000, 800);

// Initialize a Graphics object with anti-aliasing
using var graphics = Graphics.FromImage(bitmap);
graphics.TextRenderingHint = TextRenderingHint.AntiAliasGridFit;

// Define font, brush, and format for the text
var font = new Font("Arial", 24);
var brush = new SolidBrush(Color.Black);
var format = new StringFormat { Alignment = StringAlignment.Center };

// Draw the string
graphics.DrawString("Hello World!", font, brush, new RectangleF(100, 300, 800, 100), format);

// Save the image
bitmap.Save("output_text.png");

Create a Gradient Fill

// Create a bitmap object
using var bitmap = new Bitmap(800, 600);

// Initialize a Graphics object
using var graphics = Graphics.FromImage(bitmap);

// Create a linear gradient brush
var brush = new LinearGradientBrush(
    new Point(0, 0),
    new Point(800, 600),
    Color.Red,
    Color.Blue);

// Fill a rectangle with the gradient
graphics.FillRectangle(brush, new Rectangle(100, 100, 600, 400));

// Save the image
bitmap.Save("output_gradient.png");

Draw a Bezier Curve

// Create a bitmap object
using var bitmap = new Bitmap(1000, 800);

// Initialize a Graphics object
using var graphics = Graphics.FromImage(bitmap);

// Define a pen for drawing
using var pen = new Pen(Color.Green, 3);

// Define control points for Bezier curve
Point pt1 = new Point(100, 100);
Point pt2 = new Point(200, 10);
Point pt3 = new Point(350, 400);
Point pt4 = new Point(500, 300);

// Draw the Bezier curve
graphics.DrawBezier(pen, pt1, pt2, pt3, pt4);

// Save the image
bitmap.Save("output_bezier.png");

Draw to Vector SVG

// A vector canvas — drawing is captured as vector commands, not rasterized
using var svg = new SvgImage(800, 600);
using var g = svg.CreateGraphics();               // RecordingGraphics, same API as Graphics
g.Clear(Color.White);
g.DrawEllipse(new Pen(Color.Blue, 2), 100, 100, 200, 200);
g.DrawString("Hello", new Font("Arial", 16), Brushes.Black, 200, 200);
svg.Save("drawing.svg", ImageFormat.Svg);         // true vector SVG

Convert Between SVG, EMF, and Bitmap

// Load SVG, rasterize, or convert to EMF
using var svg = new SvgImage("input.svg");
svg.RenderToBitmap().Save("output.png", ImageFormat.Png);
svg.Save("output.emf", ImageFormat.Emf);          // SVG → EMF

// Convert EMF to SVG
using var emf = new Metafile("chart.emf");
emf.Save("chart.svg", ImageFormat.Svg);

Animated PNG (APNG)

using var bmp = new Bitmap("animated.apng");

int frames = bmp.GetFrameCount(FrameDimension.Time);
for (int i = 0; i < frames; i++)
{
    bmp.SelectActiveFrame(FrameDimension.Time, i);
    bmp.Save($"frame{i}.png", ImageFormat.Png);
}

Text on a Path

using var circle = new GraphicsPath();
circle.AddEllipse(100, 50, 400, 300);
graphics.DrawStringOnPath("Around the circle we go",
    new Font("Arial", 20f), brush, circle,
    new StringFormat { Alignment = StringAlignment.Center });

Rich Text, Bidi, and Font Fallback

// RTL Hebrew — renders right-to-left automatically
graphics.DrawString("שלום עולם", new Font("Arial", 24f), brush,
    new RectangleF(0, 20, 600, 40),
    new StringFormat(StringFormatFlags.DirectionRightToLeft));

// Fallback — CJK chars render from a fallback font
graphics.DrawString("Hello 世界", new Font("Arial", 24f), brush, 20f, 80f);

// Rich text — mixed fonts/styles/colors
var rich = new RichTextOptions(new FontFamily("Arial"), 18f)
{
    Runs =
    {
        new RichTextRun(0, 6),
        new RichTextRun(6, 5) { FontStyle = FontStyle.Bold },
        new RichTextRun(11, 4) { EmSize = 28f },
        new RichTextRun(15, 5) { Brush = new SolidBrush(Color.Red) },
    }
};
graphics.DrawRichText("Hello WorldBig!Red!", rich, brush, new RectangleF(20, 160, 560, 60));

System Requirements

• Target Frameworks: .NET Standard 2.0, .NET 6.0+
• Dependencies: None – all font, graphics, vector, and metafile functionality is built-in

Documentation

• DRIT.Drawing Implementation Plan
• SVG + Vector Domain Model Plan
• APNG Implementation Plan
• Text-on-Path Plan
• Rich Text / Bidi / Fallback Plan
• API Reference (coming soon)

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