UnityEditorCameraSpeed.cs

using UnityEngine;
using UnityEditor;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;

[InitializeOnLoad]
public class EditorCameraSpeed
    : EditorWindow
{
    [MenuItem("Tools/Camera Speed &S")]
    public static void CameraSpeed()
    {
        var window = GetWindow<EditorCameraSpeed>();

        // TODO: gets cleared each frame?
        SceneView.onSceneGUIDelegate += OnSceneDelegate;
    }

    static void CameraSpeedUpdate()
    {
        var e = Event.current;

        // Tools.s_LockedViewTool is ViewTool.FPS when holding right-click down
        // SceneView.OnGUI() calls SceneViewMotion.DoViewTool(self)
        // SceneViewMotion.DoViewTool(): key down event: process WASD and add to s_Motion vector
        // SceneViewMotion.DoViewTool(): layout event: view.pivot change by s_Motion * internal dt tracking

        // solution 1: try and modify speed values during this update
        // -> doesn't work because the timing of events and this call is different, and it is out of sync

        // solution 2: get a callback in our code somewhere during the gui event handler so we can modify some values
        // -> doesnt work because there seems to be no delegates or callbacks during SceneView.OnGUI that we can hook into

        // solution 3: modify ilcode bytes of SceneViewMotion.GetMovementDirection() to return a modified value
        // -> can modify ?

        // solution 4: replace kFPSPref* input keys and move the main window pivot ourselves
        // -> gotta implement a lot?

        // solution 5: build custom permanent control and listen for OnGUI()
        // -> will get events when not focused?
        // -> will get events that are consumed by scene view?
    }

    static float cameraMoveSpeed = 10.0f;
    static float cameraMoveSpeedCtrl = 1.0f;

    public void OnGUI()
    {
        var event_ = Event.current;
        var controlID = GUIUtility.GetControlID(FocusType.Passive);
        var eventType = event_.GetTypeForControl(controlID);

        cameraMoveSpeed = EditorGUILayout.Slider(cameraMoveSpeed, 0.0f, 10.0f);
        cameraMoveSpeedCtrl = EditorGUILayout.Slider(cameraMoveSpeedCtrl, 0.1f, 1.0f);

        SceneView.onSceneGUIDelegate += OnSceneDelegate;
    }

    public static void OnSceneDelegate(SceneView sceneView)
    {
        if (Event.current.type != EventType.Layout)
            return;

        var tools_type = typeof(UnityEditor.Tools);
        var locked_view_tool_field = (FieldInfo)tools_type.GetField("s_LockedViewTool", BindingFlags.NonPublic | BindingFlags.Static);
        var locked_view_tool = (ViewTool)locked_view_tool_field.GetValue(null);

        if (locked_view_tool != ViewTool.FPS)
            return;

        var scene_view_assembly = Assembly.GetAssembly(typeof(UnityEditor.SceneView));
        var scene_view_motion_type = scene_view_assembly.GetType("UnityEditor.SceneViewMotion");
        var scene_view_flyspeed_type = scene_view_assembly.GetType("UnityEditor.SceneViewMotion");

        var flyspeed_field = (FieldInfo)scene_view_motion_type.GetField("s_FlySpeed", BindingFlags.NonPublic | BindingFlags.Static);
        var flyspeed = flyspeed_field.GetValue(null);
        var flyspeed_modified = (float)flyspeed;

        flyspeed_modified = cameraMoveSpeed;

        if (Event.current.control)
            flyspeed_modified = cameraMoveSpeedCtrl;

        flyspeed_field.SetValue(null, flyspeed_modified);

        // we can stop input with this
        //Event.current.Use();
    }
}