creating-graphics-in-code

Creating WPF Graphics in Code

Programmatically create shapes and geometry for dynamic graphics.

1. Shape Factory Pattern

namespace MyApp.Graphics;

using System.Windows;
using System.Windows.Media;
using System.Windows.Shapes;

public static class ShapeFactory
{
    /// <summary>
    /// Create circular marker
    /// </summary>
    public static Ellipse CreateCircle(double size, Brush fill, Brush? stroke = null)
    {
        var ellipse = new Ellipse
        {
            Width = size,
            Height = size,
            Fill = fill
        };

        if (stroke is not null)
        {
            ellipse.Stroke = stroke;
            ellipse.StrokeThickness = 1;
        }

        return ellipse;
    }

    /// <summary>
    /// Create rectangle with optional corner radius
    /// </summary>
    public static Rectangle CreateRectangle(
        double width,
        double height,
        Brush fill,
        double cornerRadius = 0)
    {
        return new Rectangle
        {
            Width = width,
            Height = height,
            Fill = fill,
            RadiusX = cornerRadius,
            RadiusY = cornerRadius
        };
    }

    /// <summary>
    /// Create line between two points
    /// </summary>
    public static Line CreateLine(Point start, Point end, Brush stroke, double thickness = 1)
    {
        return new Line
        {
            X1 = start.X,
            Y1 = start.Y,
            X2 = end.X,
            Y2 = end.Y,
            Stroke = stroke,
            StrokeThickness = thickness
        };
    }
}

2. Geometry Builder Pattern

namespace MyApp.Graphics;

using System.Collections.Generic;
using System.Windows;
using System.Windows.Media;

public static class GeometryBuilder
{
    /// <summary>
    /// Create polygon from points
    /// </summary>
    public static PathGeometry CreatePolygon(IReadOnlyList<Point> points)
    {
        if (points.Count < 3)
            return new PathGeometry();

        var figure = new PathFigure
        {
            StartPoint = points[0],
            IsClosed = true,
            IsFilled = true
        };

        for (var i = 1; i < points.Count; i++)
        {
            figure.Segments.Add(new LineSegment(points[i], isStroked: true));
        }

        var geometry = new PathGeometry();
        geometry.Figures.Add(figure);
        return geometry;
    }

    /// <summary>
    /// Create polyline (open path)
    /// </summary>
    public static PathGeometry CreatePolyline(IReadOnlyList<Point> points)
    {
        if (points.Count < 2)
            return new PathGeometry();

        var figure = new PathFigure
        {
            StartPoint = points[0],
            IsClosed = false
        };

        for (var i = 1; i < points.Count; i++)
        {
            figure.Segments.Add(new LineSegment(points[i], isStroked: true));
        }

        var geometry = new PathGeometry();
        geometry.Figures.Add(figure);
        return geometry;
    }

    /// <summary>
    /// Create cubic Bezier curve
    /// </summary>
    public static PathGeometry CreateBezierCurve(
        Point start,
        Point control1,
        Point control2,
        Point end)
    {
        var figure = new PathFigure { StartPoint = start };
        figure.Segments.Add(new BezierSegment(control1, control2, end, isStroked: true));

        var geometry = new PathGeometry();
        geometry.Figures.Add(figure);
        return geometry;
    }

    /// <summary>
    /// Create arc
    /// </summary>
    public static PathGeometry CreateArc(
        Point start,
        Point end,
        Size size,
        SweepDirection direction = SweepDirection.Clockwise)
    {
        var figure = new PathFigure { StartPoint = start };
        figure.Segments.Add(new ArcSegment(end, size, 0, false, direction, isStroked: true));

        var geometry = new PathGeometry();
        geometry.Figures.Add(figure);
        return geometry;
    }
}