Finding the orbit under the mouse?

[zentarul]

I am trying to display contextual information about an orbit just by hovering the mouse above it. Obviously, clicking on an orbit allows you to place a maneuver node at that position, so there must be a way to translate mouse position into orbit + obit UT. The question is how? The OrbitRenderer seems to have some info about that. It has a GetMouseOverNode function and a mouseOver member, but it is not clear what they mean.

Does anyone have any insight on this?

Thanks,
Zentarul

[xEvilReeperx]

[KSPAddon(KSPAddon.Startup.Flight, false)]
public class OrbitMouseOver : MonoBehaviour
{
    private bool _mouseOver = false;
    private PatchedConics.PatchCastHit _mousedOverPatch;


    private Rect _popup = new Rect(0f, 0f, 120f, 60f);
    private Texture2D _cross;
    private Rect _crossRect;

    private void Awake()
    {
        _popup.center = new Vector2(Screen.width * 0.5f - _popup.width * 0.5f,
            Screen.height * 0.5f - _popup.height * 0.5f);

        _cross = new Texture2D(32, 32, TextureFormat.ARGB32, false);
        _crossRect = new Rect(0, 0, _cross.width, _cross.height);

        var pixels = Enumerable.Repeat(Color.clear, _cross.width * _cross.height).ToArray();

        for (int i = 0; i < _cross.width; ++i)
            for (int j = 0; j < _cross.height; ++j)
            {
                if (i == j || j == (_cross.width - i))
                    pixels[j * _cross.height + i] = Color.red;
            }

        _cross.SetPixels(pixels);
        _cross.Apply();
    }


    private void Update()
    {
        _mouseOver = MouseOverOrbit(out _mousedOverPatch);

        if (!_mouseOver) return;

        var updatedLocation = _mousedOverPatch.GetUpdatedScreenPoint();

        _popup.center = _crossRect.center = new Vector2(updatedLocation.x, Screen.height - updatedLocation.y);
    }


    private void OnGUI()
    {
        if (!_mouseOver) return;

        GUI.skin = HighLogic.Skin;


        GUILayout.BeginArea(GUIUtility.ScreenToGUIRect(_popup));
        GUILayout.Label("UT: " + KSPUtil.PrintTime((int)(Planetarium.GetUniversalTime() - _mousedOverPatch.UTatTA), 5, true));

        GUILayout.EndArea();

        if (Event.current.type == EventType.Repaint)
            Graphics.DrawTexture(_crossRect, _cross);
    }




    private bool MouseOverOrbit(out PatchedConics.PatchCastHit hit)
    {
        hit = default(PatchedConics.PatchCastHit);

        if (FlightGlobals.ActiveVessel == null) return false;

        var patchRenderer = FlightGlobals.ActiveVessel.patchedConicRenderer;

        if (patchRenderer == null) return false;

        var patches = patchRenderer.solver.maneuverNodes.Any()
            ? patchRenderer.flightPlanRenders
            : patchRenderer.patchRenders;

        return PatchedConics.ScreenCast(Input.mousePosition, patches, out hit);
    }
}

Here's a rough proof of concept. It works on the active vessel's orbit. If you want to include the other orbits (CelestialBodies at least, anyway), you'll probably want to use OrbitRenderer.OrbitCast. I didn't go far on that path other than yes/no type mouseover debug spam since it became apparent that the maneuver node placement was doing something different and the active vessel's orbit wasn't included by that method

[zentarul]

Thanks a lot xEvilReepers! Here's the result: ABookCase Orbital Reference System