refactor: moved 2D primitives from Physics2D to Core

Engine.Core/Primitives/Circle.cs

@@ -0,0 +1,113 @@
+using System.Diagnostics;
+using Syntriax.Engine.Core.Abstract;
+
+namespace Syntriax.Engine.Core;
+
+/// <summary>
+/// Represents a 2D circle.
+/// </summary>
+/// <param name="center">The center of the circle.</param>
+/// <param name="radius">The radius of the circle.</param>
+/// <remarks>
+/// Initializes a new instance of the <see cref="Circle"/> struct with the specified center and radius.
+/// </remarks>
+[DebuggerDisplay("Center: {Center.ToString(),nq}, Radius: {Radius}")]
+public readonly struct Circle(Vector2D center, float radius)
+{
+    /// <summary>
+    /// The center of the circle.
+    /// </summary>
+    public readonly Vector2D Center = center;
+
+    /// <summary>
+    /// The radius of the <see cref="Circle"/>.
+    /// </summary>
+    public readonly float Radius = radius;
+
+    /// <summary>
+    /// Gets the squared radius of the <see cref="Circle"/>.
+    /// </summary>
+    public readonly float RadiusSquared => Radius * Radius;
+
+    /// <summary>
+    /// Gets the diameter of the <see cref="Circle"/>.
+    /// </summary>
+    public readonly float Diameter => 2f * Radius;
+
+    /// <summary>
+    /// A predefined unit <see cref="Circle"/> with a center at the origin and a radius of 1.
+    /// </summary>
+    public static readonly Circle UnitCircle = new(Vector2D.Zero, 1f);
+
+    /// <summary>
+    /// Sets the center of the <see cref="Circle"/>.
+    /// </summary>
+    public static Circle SetCenter(Circle circle, Vector2D center) => new(center, circle.Radius);
+
+    /// <summary>
+    /// Sets the radius of the <see cref="Circle"/>.
+    /// </summary>
+    public static Circle SetRadius(Circle circle, float radius) => new(circle.Center, radius);
+
+    /// <summary>
+    /// Displaces the <see cref="Circle"/> by the specified <see cref="Vector2D"/>.
+    /// </summary>
+    public static Circle Displace(Circle circle, Vector2D displaceVector) => new(circle.Center + displaceVector, circle.Radius);
+
+    /// <summary>
+    /// Projects the <see cref="Circle"/> onto the specified <see cref="Vector2D"/>.
+    /// </summary>
+    public static Projection1D Project(Circle circle, Vector2D projectionVector)
+    {
+        float projectedCenter = circle.Center.Dot(projectionVector);
+        return new(projectedCenter - circle.Radius, projectedCenter + circle.Radius);
+    }
+
+    /// <summary>
+    /// Transforms the <see cref="Circle"/> by the specified <see cref="ITransform"/>.
+    /// </summary>
+    public static Circle TransformCircle(ITransform transform, Circle circle)
+        => new(transform.TransformVector2D(circle.Center), circle.Radius * (transform.Scale.Magnitude / Vector2D.One.Magnitude));
+
+    /// <summary>
+    /// Checks if two <see cref="Circle"/>s are approximately equal.
+    /// </summary>
+    public static bool ApproximatelyEquals(Circle left, Circle right)
+        => left.Center.ApproximatelyEquals(right.Center) && left.Radius.ApproximatelyEquals(right.Radius);
+}
+
+/// <summary>
+/// Provides extension methods for the <see cref="Circle"/> struct.
+/// </summary>
+public static class CircleExtensions
+{
+    /// <summary>
+    /// Sets the center of the <see cref="Circle"/>.
+    /// </summary>
+    public static Circle SetCenter(this Circle circle, Vector2D center) => Circle.SetCenter(circle, center);
+
+    /// <summary>
+    /// Sets the radius of the <see cref="Circle"/>.
+    /// </summary>
+    public static Circle SetRadius(this Circle circle, float radius) => Circle.SetRadius(circle, radius);
+
+    /// <summary>
+    /// Moves the <see cref="Circle"/> by the specified <see cref="Vector2D"/>.
+    /// </summary>
+    public static Circle Displace(this Circle circle, Vector2D displaceVector) => Circle.Displace(circle, displaceVector);
+
+    /// <summary>
+    /// Projects the <see cref="Circle"/> onto the specified <see cref="Vector2D"/>.
+    /// </summary>
+    public static Projection1D ToProjection(this Circle circle, Vector2D projectionVector) => Circle.Project(circle, projectionVector);
+
+    /// <summary>
+    /// Transforms the <see cref="Circle"/> by the specified <see cref="ITransform"/>.
+    /// </summary>
+    public static Circle TransformCircle(this ITransform transform, Circle circle) => Circle.TransformCircle(transform, circle);
+
+    /// <summary>
+    /// Checks if two <see cref="Circle"/>s are approximately equal.
+    /// </summary>
+    public static bool ApproximatelyEquals(this Circle left, Circle right) => Circle.ApproximatelyEquals(left, right);
+}