Unity Utility2D.cs

Utility2D.cs

using UnityEngine;
using System.Collections.Generic;

namespace PaulMasriStone.Utility2D
{
	public static class Utility2D
	{
		public static bool IsPointWithinCollider2D(Vector2 targetPoint, Vector2 externalPoint, int layerMask = Physics2D.DefaultRaycastLayers)
		{
			var direction = (targetPoint - externalPoint).normalized;
			var tinyNudge = direction * 0.001f; // avoids Linecast hitting the same point over and over

			RaycastHit2D hit;
			int hitCount = 0;

			var rayStart = externalPoint;
			while (rayStart != targetPoint) {
				hit = Physics2D.Linecast(rayStart, targetPoint, layerMask);
				if (hit)
				{
					hitCount++;
					rayStart = hit.point + tinyNudge;
				}
				else
					break;
			}

			return hitCount % 2 != 0;
		}

		public static bool IsPointWithinBounds(Vector2 targetPoint, Bounds bounds)
		{
			var boundRect = new Rect((Vector2)bounds.min, (Vector2)bounds.size);
			return boundRect.Contains(targetPoint);
		}

		public static Rect OrthographicRect(this Camera camera)
		{
			var center = (Vector2)camera.transform.position;
			var vExtent = camera.orthographicSize;
			var hExtent = vExtent * camera.aspect;
			var rect = new Rect(center.x - hExtent, center.y - vExtent, hExtent * 2f, vExtent * 2f);
			return rect;
		}

		public static void SetPolygonColliderPath(ref PolygonCollider2D collider, Sprite sprite)
		{
			// Remove existing path
			collider.pathCount = 0;
			
			// Set new path to match Custom Physics Shape of sprite (which must be set in Sprite Editor)
			collider.pathCount = sprite.GetPhysicsShapeCount();

			var path = new List<Vector2>();
			for (int i = 0; i < collider.pathCount; i++)
			{
				sprite.GetPhysicsShape(i, path);
				collider.SetPath(i, path.ToArray());
			}
		}
	}
}