ZoomToMouse.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using HarmonyLib;
using Game.Session.Input;
using Game.Session.Board;
using Game.Services;
using UnityEngine;

namespace TDEnhancementPack
{
	//------------------
	//Stack zoom requests
	//------------------
	[HarmonyPatch(typeof(BaseInputMode), nameof(BaseInputMode.OnZoom))]
	public static class StackZoomWheel
	{
		//public virtual bool OnZoom(Vector2? pos, float zoomfactor, bool tween)
		public static bool Prefix(ref bool __result, BaseInputMode __instance, float zoomfactor, bool tween)
		{
			if (Game.Util.UIUtil.IsInputOverUI)
			{
				__result = false;
				return false;
			}
			zoomfactor /= 3;//Honestly it's zooming too fast.

			//float zoom = Game.Game.serv.camera.GetZoom();
			//This is the current zoom, but where is it currently zooming to?

			float zoom = DesiredZoom.desiredZoom;

			float zoomFactor = 1f + Mathf.Abs(zoomfactor * __instance.ZoomMultiplier);
			zoom = zoomfactor >= 0f ? (zoom / zoomFactor) : (zoom * zoomFactor);
			__instance._isDown = false;
			Game.Game.serv.camera.SetZoom(zoom, tween, 0.15f);
			__result = true;

			return false;
		}
	}

	[HarmonyPatch(typeof(CameraService), nameof(CameraService.SetZoom))]
	public static class DesiredZoom
	{
		public static float desiredZoom;
		//public void SetZoom(float zoom, bool tween, float tweenSeconds = 0.3f)
		public static void Prefix(CameraService __instance, float zoom)
		{
			desiredZoom = __instance.ClampZoom(zoom);//Whether it's instant or gradual, this is where we're headed.
		}
	}

	//------------------
	//Zoom to mouse
	//------------------
	[HarmonyPatch(typeof(CameraService), nameof(CameraService.CameraZoomHelper))]
	public static class ZoomToMouse
	{
		//private void CameraZoomHelper(float val)
		public static bool Prefix(CameraService __instance, float val)
		{
			//Get where the mouse is
			Vector3 mousePosition = UnityEngine.Input.mousePosition;
			WorldPos oldpos = __instance.ScreenToWorldPos(mousePosition);

			//Apply zoom
			val = __instance.ClampZoom(val);
			__instance.main.orthographicSize = val;

			//Find out where we are now:
			WorldPos newpos = __instance.ScreenToWorldPos(mousePosition);

			//Find how much we slide away from cursor and adjust:
			Vector3 newTransform = new Vector3(
				__instance.main.transform.position.x + oldpos.x - newpos.x,
				__instance.main.transform.position.y + oldpos.y - newpos.y,
				__instance.main.transform.position.z);

			//clamp panning position for out of bounds
			Vector2 transformPos = __instance.ClampPos(newTransform, val);
			//ClampPos takes Vector3 spits out a Vector 2 :/
			newTransform.x = transformPos.x; newTransform.y = transformPos.y;

			//And set it
			__instance.main.transform.position = newTransform;

			__instance.OnCameraZoomChanged.Invoke();

			return false;
		}
	}
}