UI-based Hotspot icons

This script allows Hotspot icons to be drawn uwing Unity UI, allowing for smooth motion, or animating them if needed.

To use it:

1. Create a new C# script named HotspotIconsUI and copy/paste the code below
2. Create a new Unity UI Canvas, and attach an Image as a child. This Image will be used as the basis for the icons.
3. Attach the new Hotspot Icons UI component to the Canvas, and fill in its Inspector

HotspotIconsUI.cs:

using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using AC;

public class HotspotIconsUI : MonoBehaviour
{

	public Image iconToDuplicate;
	public CanvasScaler canvasScaler;
	private Dictionary<Hotspot, Image> hotspotIconDict = new Dictionary<Hotspot, Image> ();

	private void OnValidate ()
	{
		if (canvasScaler == null) canvasScaler = GetComponent<CanvasScaler> ();
		if (iconToDuplicate == null) iconToDuplicate = GetComponentInChildren<Image> ();
	}

	private void Awake ()
	{
		Hotspot[] hotspots = Object.FindObjectsOfType<Hotspot> ();
		foreach (Hotspot hotspot in hotspots)
		{
			if (hotspot.highlight == null) continue;

			Image icon = Instantiate (iconToDuplicate.gameObject).GetComponent<Image> ();
			icon.transform.SetParent (iconToDuplicate.transform.parent);
			icon.gameObject.name += "_" + hotspot.name;
			hotspotIconDict.Add (hotspot, icon);
		}

		iconToDuplicate.gameObject.SetActive (false);
	}

	private void LateUpdate ()
	{
		foreach (Hotspot hotspot in hotspotIconDict.Keys)
		{
			Image icon = hotspotIconDict[hotspot];
			icon.color = new Color (icon.color.r, icon.color.g, icon.color.b, hotspot.highlight.GetHighlightAlpha ());
			icon.sprite = hotspot.GetMainIcon ().GetAnimatedSprite (true);

			Vector2 screenPos = hotspot.GetIconScreenPosition ();

			float scalerOffset = 1f;

			if (canvasScaler && canvasScaler.enabled && canvasScaler.uiScaleMode == CanvasScaler.ScaleMode.ScaleWithScreenSize)
			{
				switch (canvasScaler.screenMatchMode)
				{
					case CanvasScaler.ScreenMatchMode.MatchWidthOrHeight:
						float match = canvasScaler.matchWidthOrHeight;
						scalerOffset = (ACScreen.width / canvasScaler.referenceResolution.x) * (1 - match) + (ACScreen.height / canvasScaler.referenceResolution.y) * match;
						break;

					case CanvasScaler.ScreenMatchMode.Expand:
						scalerOffset = Mathf.Min (ACScreen.width / canvasScaler.referenceResolution.x, ACScreen.height / canvasScaler.referenceResolution.y);
						break;

					case CanvasScaler.ScreenMatchMode.Shrink:
						scalerOffset = Mathf.Max (ACScreen.width / canvasScaler.referenceResolution.x, ACScreen.height / canvasScaler.referenceResolution.y);
						break;
				}
			}

			Rect safeScreenRect = ACScreen.safeArea;
			Vector2 diff = new Vector2 (ACScreen.width, ACScreen.height) - safeScreenRect.position - safeScreenRect.position - safeScreenRect.size;
			screenPos += diff / 2f;

			Vector3 localTargetPositionUI = new Vector3 ((screenPos.x - (ACScreen.width / 2f)) / scalerOffset, (screenPos.y - (ACScreen.height / 2f)) / scalerOffset, icon.rectTransform.transform.localPosition.z);

			icon.rectTransform.localPosition = localTargetPositionUI;
		}
	}

}