Issue with GUI repaint

Unity Engine
,
1

Hello there,
I am working on a Unity tool and at the moment I am having some difficulties with the GUI repaint.

I want to create a custom GUI. In this simple script, I am checking if the mouse has hovered over a button and if so I change a GUI color. This is just a really basic example, but the same principles apply to something that I want to make.

The problem is that the change is really delayed. I tried implementing isDirty state, where it only repaints when it needs to. Although it doesn’t seem to work. Same delay issue… I could just repaint the window every frame, but that is really non-performant. What could be a good solution for this? Thank you

Script:

    private bool isDirty = false;

    Rect _hoveredRect;
    Rect HoveredRect
    {
        get { return _hoveredRect; }
        set
        {
            if (_hoveredRect != value)
            {
                isDirty = true;
            }
            _hoveredRect = value;
        }
    }

    void Update()
    {
        if (isDirty)
        {
            Repaint();
            isDirty = false;
        }
    }
    void OnGUI()
    {
        Rect button = new Rect(25, 25, 100, 35);
        DrawButton(button, "Label");
    }
    bool DrawButton(Rect rect, string label)
    {
        var e = Event.current;
        bool hovered = rect.Contains(e.mousePosition);

        if (hovered)
        {
            HoveredRect = rect;
        }
        if (!hovered && HoveredRect == rect)
        {
            HoveredRect = Rect.zero;
        }

        var defaultColor = GUI.color;

        GUI.color = hovered ? Color.red : defaultColor;

        bool pressed = GUI.Button(rect, label);

        GUI.color = defaultColor;

        return pressed;
    }
2

I think maybe you can get snappier updates from:

3

Hey, thanks! I tried using this but it didn’t really make much difference, unfortunately. I think I came up with a solution, although I need to get a mouse position outside on OnGUI. This is an issue as Event.current is null outside OnGUI. Is there a way to get mouse position outside OnGUI function?

The solution (probably not the best, but should work I think, if I can get mouse pos):

    Dictionary<Rect, bool> hoverableRects = new Dictionary<Rect, bool>();

    private void OnEnable()
    {
        EditorApplication.update += UpdateMe;
    }
    private void OnDisable()
    {
        EditorApplication.update -= UpdateMe;
    }

    void UpdateMe()
    {
        var mousePos = ??; List<Rect> rects = new List<Rect>(hoverableRects.Keys);
        foreach (var rect in rects)
        {
            hoverableRects[rect] = rect.Contains(mousePos);
        }
    }
    void OnGUI()
    {
        Rect button = new Rect(25, 25, 100, 35);
        DrawButton(button, "Label");
    }
    bool DrawButton(Rect rect, string label)
    {
        if (!hoverableRects.ContainsKey(rect))
        { hoverableRects.Add(rect, false); }

        var defaultColor = GUI.color;

        GUI.color = hoverableRects[rect] ? Color.red : defaultColor;

        bool pressed = GUI.Button(rect, label);

        GUI.color = defaultColor;

        return pressed;
    }
4

Raw mouse position is always “live” on Input.mousePosition

5

I tried using Input.mousePosition, but it always return (0, 0, 0) :confused:

6

Pardon, I missed the part where you said you were working on an editor tool. My bad.

Try this instead:

https://answers.unity.com/questions/829071/get-mouse-position-in-editor-based-on-screen-coord.html

7

The point is that I need to get mouse position every frame outside the OnGUI, so I am unable to use Event.current. It returns null when I try to access it.
Is there a way to either get mouse on-screen position coordinated or maybe subscribe to some onMouseMoved that fires every time mouse position is changed, not just in this window, but in general?

8

You might have to pick it up in OnGUI and stick that position in a class instance variable for other parts of the code to use.

Yes, icky, but likely workee… :slight_smile:

9

Tried that as well, but still has the same delay issue as OnGUI is not called every frame and the position is not constantly updated :
I can’t believe it’s that difficult to get a mouse position… I’ll try to see if I can come up with something I suppose, I’ve been trying to do this an entire day today, this is ridiculous :smile: