//======= Copyright (c) Valve Corporation, All rights reserved. ===============
//
// Purpose: Sets cubemap to use in the compositor.
//
//=============================================================================

using UnityEngine;
using Valve.VR;

namespace Valve.VR
{
    public class SteamVR_Skybox : MonoBehaviour
    {
        // Note: Unity's Left and Right Skybox shader variables are switched.
        public Texture front, back, left, right, top, bottom;

        public enum CellSize
        {
            x1024, x64, x32, x16, x8
        }
        public CellSize StereoCellSize = CellSize.x32;

        public float StereoIpdMm = 64.0f;

        public void SetTextureByIndex(int i, Texture t)
        {
            switch (i)
            {
                case 0:
                    front = t;
                    break;
                case 1:
                    back = t;
                    break;
                case 2:
                    left = t;
                    break;
                case 3:
                    right = t;
                    break;
                case 4:
                    top = t;
                    break;
                case 5:
                    bottom = t;
                    break;
            }
        }

        public Texture GetTextureByIndex(int i)
        {
            switch (i)
            {
                case 0:
                    return front;
                case 1:
                    return back;
                case 2:
                    return left;
                case 3:
                    return right;
                case 4:
                    return top;
                case 5:
                    return bottom;
            }
            return null;
        }

        static public void SetOverride(
            Texture front = null,
            Texture back = null,
            Texture left = null,
            Texture right = null,
            Texture top = null,
            Texture bottom = null)
        {
            var compositor = OpenVR.Compositor;
            if (compositor != null)
            {
                var handles = new Texture[] { front, back, left, right, top, bottom };
                var textures = new Texture_t[6];
                for (int i = 0; i < 6; i++)
                {
                    textures[i].handle = (handles[i] != null) ? handles[i].GetNativeTexturePtr() : System.IntPtr.Zero;
                    textures[i].eType = SteamVR.instance.textureType;
                    textures[i].eColorSpace = EColorSpace.Auto;
                }
                var error = compositor.SetSkyboxOverride(textures);
                if (error != EVRCompositorError.None)
                {
                    Debug.LogError("<b>[SteamVR]</b> Failed to set skybox override with error: " + error);
                    if (error == EVRCompositorError.TextureIsOnWrongDevice)
                        Debug.Log("<b>[SteamVR]</b> Set your graphics driver to use the same video card as the headset is plugged into for Unity.");
                    else if (error == EVRCompositorError.TextureUsesUnsupportedFormat)
                        Debug.Log("<b>[SteamVR]</b> Ensure skybox textures are not compressed and have no mipmaps.");
                }
            }
        }

        static public void ClearOverride()
        {
            var compositor = OpenVR.Compositor;
            if (compositor != null)
                compositor.ClearSkyboxOverride();
        }

        void OnEnable()
        {
            SetOverride(front, back, left, right, top, bottom);
        }

        void OnDisable()
        {
            ClearOverride();
        }
    }
}