From a8065c0ea5db8ec1dacc4ac3ccb7f73b98233407 Mon Sep 17 00:00:00 2001
From: Cat Flynn <me@ktyl.dev>
Date: Mon, 5 Sep 2022 19:40:39 +0100
Subject: [PATCH] add camera zoom

---
 scenes/OrbitCamera.tscn |  2 ++
 scripts/OrbitCamera.cs  | 41 +++++++++++++++++++++++++++++++++++++----
 2 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/scenes/OrbitCamera.tscn b/scenes/OrbitCamera.tscn
index 5a203e7..5486939 100644
--- a/scenes/OrbitCamera.tscn
+++ b/scenes/OrbitCamera.tscn
@@ -4,6 +4,8 @@
 
 [node name="OrbitCamera" type="Spatial"]
 script = ExtResource( 1 )
+_zoomSensitivity = 50.0
+_cameraPath = NodePath("Camera")
 
 [node name="Camera" type="Camera" parent="."]
 transform = Transform( 1, 0, 0, 0, 0.964146, 0.265371, 0, -0.265371, 0.964146, 0, 2.21115, 9.48434 )
diff --git a/scripts/OrbitCamera.cs b/scripts/OrbitCamera.cs
index 55763eb..feac7d0 100644
--- a/scripts/OrbitCamera.cs
+++ b/scripts/OrbitCamera.cs
@@ -4,7 +4,25 @@ using System;
 public class OrbitCamera : Spatial
 {
     [Export]
-    private float _sensitivity = 200f;
+    private float _lookSensitivity = 200f;
+
+    [Export]
+    private float _zoomSensitivity = 10f;
+
+    [Export]
+    private NodePath _cameraPath;
+    private Camera _camera = null;
+    private Camera Camera
+    {
+        get
+        {
+            if (_camera == null)
+            {
+                _camera = GetNode<Camera>(_cameraPath);
+            }
+            return _camera;
+        }
+    }
 
     private Vector2 _rotation;
     private bool _canRotate = false;
@@ -24,7 +42,8 @@ public class OrbitCamera : Spatial
     public override void _Process(float delta)
     {
         Rotation = Vector3.Zero;
-        var sensitivity = -1f / _sensitivity;
+        var sensitivity = -1f / _lookSensitivity;
+
         Rotate(Vector3.Right, _rotation.y * sensitivity);
         Rotate(Vector3.Up, _rotation.x * sensitivity);
     }
@@ -32,9 +51,23 @@ public class OrbitCamera : Spatial
     // left click to drag
     private void HandleMouseButton(InputEventMouseButton mouseButton)
     {
-        if (mouseButton.ButtonIndex != (int)ButtonList.Left) return;
+        switch ((ButtonList)mouseButton.ButtonIndex)
+        {
+            case ButtonList.Left:
+                _canRotate = mouseButton.Pressed;
+                break;
+            case ButtonList.WheelUp:
+                Zoom(-1);
+                break;
+            case ButtonList.WheelDown:
+                Zoom(1);
+                break;
+        }
+    }
 
-        _canRotate = mouseButton.Pressed;
+    private void Zoom(float amount)
+    {
+        Camera.Fov += amount * _zoomSensitivity / Camera.Fov;
     }
 
     private void HandleMouseMovement(InputEventMouseMotion mouseMotion)