From ce823c06b6418255a9c6926eb31d6674e3697598 Mon Sep 17 00:00:00 2001
From: Cat Flynn <me@ktyl.dev>
Date: Sun, 4 Sep 2022 17:37:35 +0100
Subject: [PATCH] drag to rotate camera

---
 scenes/OrbitCamera.tscn |  2 +-
 scripts/OrbitCamera.cs  | 37 +++++++++++++++++++++++++++++++++----
 2 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/scenes/OrbitCamera.tscn b/scenes/OrbitCamera.tscn
index 4780caa..5a203e7 100644
--- a/scenes/OrbitCamera.tscn
+++ b/scenes/OrbitCamera.tscn
@@ -6,5 +6,5 @@
 script = ExtResource( 1 )
 
 [node name="Camera" type="Camera" parent="."]
-transform = Transform( 1, 0, 0, 0, 0.913325, 0.407231, 0, -0.407231, 0.913325, 0, 24.1191, 58.6188 )
+transform = Transform( 1, 0, 0, 0, 0.964146, 0.265371, 0, -0.265371, 0.964146, 0, 2.21115, 9.48434 )
 fov = 25.0
diff --git a/scripts/OrbitCamera.cs b/scripts/OrbitCamera.cs
index 2aa7677..55763eb 100644
--- a/scripts/OrbitCamera.cs
+++ b/scripts/OrbitCamera.cs
@@ -4,15 +4,44 @@ using System;
 public class OrbitCamera : Spatial
 {
     [Export]
-    private float _speed;
+    private float _sensitivity = 200f;
 
-    public override void _Ready()
+    private Vector2 _rotation;
+    private bool _canRotate = false;
+
+    public override void _Input(InputEvent e)
     {
-
+        if (e is InputEventMouseMotion mouseMotion)
+        {
+            HandleMouseMovement(mouseMotion);
+        }
+        if (e is InputEventMouseButton mouseButton)
+        {
+            HandleMouseButton(mouseButton);
+        }
     }
 
     public override void _Process(float delta)
     {
-        Rotate(Vector3.Up, _speed * delta);
+        Rotation = Vector3.Zero;
+        var sensitivity = -1f / _sensitivity;
+        Rotate(Vector3.Right, _rotation.y * sensitivity);
+        Rotate(Vector3.Up, _rotation.x * sensitivity);
+    }
+
+    // left click to drag
+    private void HandleMouseButton(InputEventMouseButton mouseButton)
+    {
+        if (mouseButton.ButtonIndex != (int)ButtonList.Left) return;
+
+        _canRotate = mouseButton.Pressed;
+    }
+
+    private void HandleMouseMovement(InputEventMouseMotion mouseMotion)
+    {
+        if (!_canRotate) return;
+
+        var delta = mouseMotion.Relative;
+        _rotation += delta;
     }
 }