using System;
using System.Collections.Generic;
using System.Linq;

namespace UnityEngine.Rendering
{
    using UnityObject = UnityEngine.Object;

    public static class CoreUtils
    {
        // Data useful for various cubemap processes.
        // Ref: https://msdn.microsoft.com/en-us/library/windows/desktop/bb204881(v=vs.85).aspx
        static public readonly Vector3[] lookAtList =
        {
            new Vector3(1.0f, 0.0f, 0.0f),
            new Vector3(-1.0f, 0.0f, 0.0f),
            new Vector3(0.0f, 1.0f, 0.0f),
            new Vector3(0.0f, -1.0f, 0.0f),
            new Vector3(0.0f, 0.0f, 1.0f),
            new Vector3(0.0f, 0.0f, -1.0f),
        };

        static public readonly Vector3[] upVectorList =
        {
            new Vector3(0.0f, 1.0f, 0.0f),
            new Vector3(0.0f, 1.0f, 0.0f),
            new Vector3(0.0f, 0.0f, -1.0f),
            new Vector3(0.0f, 0.0f, 1.0f),
            new Vector3(0.0f, 1.0f, 0.0f),
            new Vector3(0.0f, 1.0f, 0.0f),
        };

        public const int editMenuPriority1 = 320;
        public const int editMenuPriority2 = 331;
        public const int editMenuPriority3 = 342;
        public const int assetCreateMenuPriority1 = 230;
        public const int assetCreateMenuPriority2 = 241;
        public const int assetCreateMenuPriority3 = 300;
        public const int gameObjectMenuPriority = 10;

        static Cubemap m_BlackCubeTexture;
        public static Cubemap blackCubeTexture
        {
            get
            {
                if (m_BlackCubeTexture == null)
                {
                    m_BlackCubeTexture = new Cubemap(1, TextureFormat.ARGB32, false);
                    for (int i = 0; i < 6; ++i)
                        m_BlackCubeTexture.SetPixel((CubemapFace)i, 0, 0, Color.black);
                    m_BlackCubeTexture.Apply();
                }

                return m_BlackCubeTexture;
            }
        }

        static Cubemap m_MagentaCubeTexture;
        public static Cubemap magentaCubeTexture
        {
            get
            {
                if (m_MagentaCubeTexture == null)
                {
                    m_MagentaCubeTexture = new Cubemap(1, TextureFormat.ARGB32, false);
                    for (int i = 0; i < 6; ++i)
                        m_MagentaCubeTexture.SetPixel((CubemapFace)i, 0, 0, Color.magenta);
                    m_MagentaCubeTexture.Apply();
                }

                return m_MagentaCubeTexture;
            }
        }

        static CubemapArray m_MagentaCubeTextureArray;
        public static CubemapArray magentaCubeTextureArray
        {
            get
            {
                if (m_MagentaCubeTextureArray == null)
                {
                    m_MagentaCubeTextureArray = new CubemapArray(1, 1, TextureFormat.RGBAFloat, false);
                    for (int i = 0; i < 6; ++i)
                    {
                        Color[] colors = { Color.magenta };
                        m_MagentaCubeTextureArray.SetPixels(colors, (CubemapFace)i, 0);
                    }
                    m_MagentaCubeTextureArray.Apply();
                }

                return m_MagentaCubeTextureArray;
            }
        }

        static Cubemap m_WhiteCubeTexture;
        public static Cubemap whiteCubeTexture
        {
            get
            {
                if (m_WhiteCubeTexture == null)
                {
                    m_WhiteCubeTexture = new Cubemap(1, TextureFormat.ARGB32, false);
                    for (int i = 0; i < 6; ++i)
                        m_WhiteCubeTexture.SetPixel((CubemapFace)i, 0, 0, Color.white);
                    m_WhiteCubeTexture.Apply();
                }

                return m_WhiteCubeTexture;
            }
        }

        static RenderTexture m_EmptyUAV;
        public static RenderTexture emptyUAV
        {
            get
            {
                if (m_EmptyUAV == null)
                {
                    m_EmptyUAV = new RenderTexture(1, 1, 0);
                    m_EmptyUAV.enableRandomWrite = true;
                    m_EmptyUAV.Create();
                }

                return m_EmptyUAV;
            }
        }

        static Texture3D m_BlackVolumeTexture;
        public static Texture3D blackVolumeTexture
        {
            get
            {
                if (m_BlackVolumeTexture == null)
                {
                    Color[] colors = { Color.black };
                    m_BlackVolumeTexture = new Texture3D(1, 1, 1, TextureFormat.ARGB32, false);
                    m_BlackVolumeTexture.SetPixels(colors, 0);
                    m_BlackVolumeTexture.Apply();
                }

                return m_BlackVolumeTexture;
            }
        }

        public static void ClearRenderTarget(CommandBuffer cmd, ClearFlag clearFlag, Color clearColor)
        {
            if (clearFlag != ClearFlag.None)
                cmd.ClearRenderTarget((clearFlag & ClearFlag.Depth) != 0, (clearFlag & ClearFlag.Color) != 0, clearColor);
        }

        // Render Target Management.
        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier buffer, ClearFlag clearFlag, Color clearColor, int miplevel = 0, CubemapFace cubemapFace = CubemapFace.Unknown, int depthSlice = 0)
        {
            cmd.SetRenderTarget(buffer, miplevel, cubemapFace, depthSlice);
            ClearRenderTarget(cmd, clearFlag, clearColor);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier buffer, ClearFlag clearFlag = ClearFlag.None, int miplevel = 0, CubemapFace cubemapFace = CubemapFace.Unknown, int depthSlice = 0)
        {
            SetRenderTarget(cmd, buffer, clearFlag, Color.clear, miplevel, cubemapFace, depthSlice);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier colorBuffer, RenderTargetIdentifier depthBuffer, int miplevel = 0, CubemapFace cubemapFace = CubemapFace.Unknown, int depthSlice = 0)
        {
            SetRenderTarget(cmd, colorBuffer, depthBuffer, ClearFlag.None, Color.clear, miplevel, cubemapFace, depthSlice);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier colorBuffer, RenderTargetIdentifier depthBuffer, ClearFlag clearFlag, int miplevel = 0, CubemapFace cubemapFace = CubemapFace.Unknown, int depthSlice = 0)
        {
            SetRenderTarget(cmd, colorBuffer, depthBuffer, clearFlag, Color.clear, miplevel, cubemapFace, depthSlice);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier colorBuffer, RenderTargetIdentifier depthBuffer, ClearFlag clearFlag, Color clearColor, int miplevel = 0, CubemapFace cubemapFace = CubemapFace.Unknown, int depthSlice = 0)
        {
            cmd.SetRenderTarget(colorBuffer, depthBuffer, miplevel, cubemapFace, depthSlice);
            ClearRenderTarget(cmd, clearFlag, clearColor);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier[] colorBuffers, RenderTargetIdentifier depthBuffer)
        {
            SetRenderTarget(cmd, colorBuffers, depthBuffer, ClearFlag.None, Color.clear);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier[] colorBuffers, RenderTargetIdentifier depthBuffer, ClearFlag clearFlag = ClearFlag.None)
        {
            SetRenderTarget(cmd, colorBuffers, depthBuffer, clearFlag, Color.clear);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier[] colorBuffers, RenderTargetIdentifier depthBuffer, ClearFlag clearFlag, Color clearColor)
        {
            cmd.SetRenderTarget(colorBuffers, depthBuffer, 0, CubemapFace.Unknown, -1);
            ClearRenderTarget(cmd, clearFlag, clearColor);
        }

        // Explicit load and store actions
        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier buffer, RenderBufferLoadAction loadAction, RenderBufferStoreAction storeAction, ClearFlag clearFlag, Color clearColor)
        {
            cmd.SetRenderTarget(buffer, loadAction, storeAction);
            ClearRenderTarget(cmd, clearFlag, clearColor);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier buffer, RenderBufferLoadAction loadAction, RenderBufferStoreAction storeAction, ClearFlag clearFlag)
        {
            SetRenderTarget(cmd, buffer, loadAction, storeAction, clearFlag, Color.clear);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier colorBuffer, RenderBufferLoadAction colorLoadAction, RenderBufferStoreAction colorStoreAction,
            RenderTargetIdentifier depthBuffer, RenderBufferLoadAction depthLoadAction, RenderBufferStoreAction depthStoreAction,
            ClearFlag clearFlag, Color clearColor)
        {
            cmd.SetRenderTarget(colorBuffer, colorLoadAction, colorStoreAction, depthBuffer, depthLoadAction, depthStoreAction);
            ClearRenderTarget(cmd, clearFlag, clearColor);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier colorBuffer, RenderBufferLoadAction colorLoadAction, RenderBufferStoreAction colorStoreAction,
            RenderTargetIdentifier depthBuffer, RenderBufferLoadAction depthLoadAction, RenderBufferStoreAction depthStoreAction,
            ClearFlag clearFlag)
        {
            SetRenderTarget(cmd, colorBuffer, colorLoadAction, colorStoreAction, depthBuffer, depthLoadAction, depthStoreAction, clearFlag, Color.clear);
        }

        private static void SetViewportAndClear(CommandBuffer cmd, RTHandle buffer, ClearFlag clearFlag, Color clearColor)
        {
            // Clearing a partial viewport currently does not go through the hardware clear.
            // Instead it goes through a quad rendered with a specific shader.
            // When enabling wireframe mode in the scene view, unfortunately it overrides this shader thus breaking every clears.
            // That's why in the editor we don't set the viewport before clearing (it's set to full screen by the previous SetRenderTarget) but AFTER so that we benefit from un-bugged hardware clear.
            // We consider that the small loss in performance is acceptable in the editor.
            // A refactor of wireframe is needed before we can fix this properly (with not doing anything!)
#if !UNITY_EDITOR
            SetViewport(cmd, buffer);
#endif
            CoreUtils.ClearRenderTarget(cmd, clearFlag, clearColor);
#if UNITY_EDITOR
            SetViewport(cmd, buffer);
#endif
        }

        // This set of RenderTarget management methods is supposed to be used when rendering into a camera dependent render texture.
        // This will automatically set the viewport based on the camera size and the RTHandle scaling info.
        public static void SetRenderTarget(CommandBuffer cmd, RTHandle buffer, ClearFlag clearFlag, Color clearColor, int miplevel = 0, CubemapFace cubemapFace = CubemapFace.Unknown, int depthSlice = -1)
        {
            // We use -1 as a default value because when doing SPI for XR, it will bind the full texture array by default (and has no effect on 2D textures)
            // Unfortunately, for cubemaps, passing -1 does not work for faces other than the first one, so we fall back to 0 in this case.
            if (depthSlice == -1 && buffer.rt.dimension == TextureDimension.Cube)
                depthSlice = 0;
            cmd.SetRenderTarget(buffer, miplevel, cubemapFace, depthSlice);
            SetViewportAndClear(cmd, buffer, clearFlag, clearColor);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RTHandle buffer, ClearFlag clearFlag = ClearFlag.None, int miplevel = 0, CubemapFace cubemapFace = CubemapFace.Unknown, int depthSlice = -1)
            => SetRenderTarget(cmd, buffer, clearFlag, Color.clear, miplevel, cubemapFace, depthSlice);

        public static void SetRenderTarget(CommandBuffer cmd, RTHandle colorBuffer, RTHandle depthBuffer, int miplevel = 0, CubemapFace cubemapFace = CubemapFace.Unknown, int depthSlice = -1)
        {
            int cw = colorBuffer.rt.width;
            int ch = colorBuffer.rt.height;
            int dw = depthBuffer.rt.width;
            int dh = depthBuffer.rt.height;

            Debug.Assert(cw == dw && ch == dh);

            SetRenderTarget(cmd, colorBuffer, depthBuffer, ClearFlag.None, Color.clear, miplevel, cubemapFace, depthSlice);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RTHandle colorBuffer, RTHandle depthBuffer, ClearFlag clearFlag, int miplevel = 0, CubemapFace cubemapFace = CubemapFace.Unknown, int depthSlice = -1)
        {
            int cw = colorBuffer.rt.width;
            int ch = colorBuffer.rt.height;
            int dw = depthBuffer.rt.width;
            int dh = depthBuffer.rt.height;

            Debug.Assert(cw == dw && ch == dh);

            SetRenderTarget(cmd, colorBuffer, depthBuffer, clearFlag, Color.clear, miplevel, cubemapFace, depthSlice);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RTHandle colorBuffer, RTHandle depthBuffer, ClearFlag clearFlag, Color clearColor, int miplevel = 0, CubemapFace cubemapFace = CubemapFace.Unknown, int depthSlice = -1)
        {
            int cw = colorBuffer.rt.width;
            int ch = colorBuffer.rt.height;
            int dw = depthBuffer.rt.width;
            int dh = depthBuffer.rt.height;

            Debug.Assert(cw == dw && ch == dh);

            CoreUtils.SetRenderTarget(cmd, colorBuffer.rt, depthBuffer.rt, miplevel, cubemapFace, depthSlice);
            SetViewportAndClear(cmd, colorBuffer, clearFlag, clearColor);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier[] colorBuffers, RTHandle depthBuffer)
        {
            CoreUtils.SetRenderTarget(cmd, colorBuffers, depthBuffer.rt, ClearFlag.None, Color.clear);
            SetViewport(cmd, depthBuffer);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier[] colorBuffers, RTHandle depthBuffer, ClearFlag clearFlag = ClearFlag.None)
        {
            CoreUtils.SetRenderTarget(cmd, colorBuffers, depthBuffer.rt); // Don't clear here, viewport needs to be set before we do.
            SetViewportAndClear(cmd, depthBuffer, clearFlag, Color.clear);
        }

        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier[] colorBuffers, RTHandle depthBuffer, ClearFlag clearFlag, Color clearColor)
        {
            cmd.SetRenderTarget(colorBuffers, depthBuffer);
            SetViewportAndClear(cmd, depthBuffer, clearFlag, clearColor);
        }

        // Scaling viewport is done for auto-scaling render targets.
        // In the context of HDRP, every auto-scaled RT is scaled against the maximum RTHandles reference size (that can only grow).
        // When we render using a camera whose viewport is smaller than the RTHandles reference size (and thus smaller than the RT actual size), we need to set it explicitly (otherwise, native code will set the viewport at the size of the RT)
        // For auto-scaled RTs (like for example a half-resolution RT), we need to scale this viewport accordingly.
        // For non scaled RTs we just do nothing, the native code will set the viewport at the size of the RT anyway.
        public static void SetViewport(CommandBuffer cmd, RTHandle target)
        {
            if (target.useScaling)
            {
                Vector2Int scaledViewportSize = target.GetScaledSize(target.rtHandleProperties.currentViewportSize);
                cmd.SetViewport(new Rect(0.0f, 0.0f, scaledViewportSize.x, scaledViewportSize.y));
            }
        }

        public static string GetRenderTargetAutoName(int width, int height, int depth, RenderTextureFormat format, string name, bool mips = false, bool enableMSAA = false, MSAASamples msaaSamples = MSAASamples.None)
        {
            string result = string.Format("{0}_{1}x{2}", name, width, height);

            if (depth > 1)
                result = string.Format("{0}x{1}", result, depth);

            if (mips)
                result = string.Format("{0}_{1}", result, "Mips");

            result = string.Format("{0}_{1}", result, format);

            if (enableMSAA)
                result = string.Format("{0}_{1}", result, msaaSamples.ToString());

            return result;
        }

        public static string GetTextureAutoName(int width, int height, TextureFormat format, TextureDimension dim = TextureDimension.None, string name = "", bool mips = false, int depth = 0)
        {
            string temp;
            if (depth == 0)
                temp = string.Format("{0}x{1}{2}_{3}", width, height, mips ? "_Mips" : "", format);
            else
                temp = string.Format("{0}x{1}x{2}{3}_{4}", width, height, depth, mips ? "_Mips" : "", format);
            temp = String.Format("{0}_{1}_{2}", name == "" ? "Texture" : name, (dim == TextureDimension.None) ? "" : dim.ToString(), temp);

            return temp;
        }

        public static void ClearCubemap(CommandBuffer cmd, RenderTexture renderTexture, Color clearColor, bool clearMips = false)
        {
            int mipCount = 1;
            if (renderTexture.useMipMap && clearMips)
            {
                mipCount = (int)Mathf.Log((float)renderTexture.width, 2.0f) + 1;
            }

            for (int i = 0; i < 6; ++i)
            {
                for (int mip = 0; mip < mipCount; ++mip)
                {
                    SetRenderTarget(cmd, new RenderTargetIdentifier(renderTexture), ClearFlag.Color, clearColor, mip, (CubemapFace)i);
                }
            }
        }

        // Draws a full screen triangle as a faster alternative to drawing a full screen quad.
        public static void DrawFullScreen(CommandBuffer commandBuffer, Material material,
            MaterialPropertyBlock properties = null, int shaderPassId = 0)
        {
            commandBuffer.DrawProcedural(Matrix4x4.identity, material, shaderPassId, MeshTopology.Triangles, 3, 1, properties);
        }

        public static void DrawFullScreen(CommandBuffer commandBuffer, Material material,
            RenderTargetIdentifier colorBuffer,
            MaterialPropertyBlock properties = null, int shaderPassId = 0)
        {
            commandBuffer.SetRenderTarget(colorBuffer);
            commandBuffer.DrawProcedural(Matrix4x4.identity, material, shaderPassId, MeshTopology.Triangles, 3, 1, properties);
        }

        public static void DrawFullScreen(CommandBuffer commandBuffer, Material material,
            RenderTargetIdentifier colorBuffer, RenderTargetIdentifier depthStencilBuffer,
            MaterialPropertyBlock properties = null, int shaderPassId = 0)
        {
            commandBuffer.SetRenderTarget(colorBuffer, depthStencilBuffer, 0, CubemapFace.Unknown, -1);
            commandBuffer.DrawProcedural(Matrix4x4.identity, material, shaderPassId, MeshTopology.Triangles, 3, 1, properties);
        }

        public static void DrawFullScreen(CommandBuffer commandBuffer, Material material,
            RenderTargetIdentifier[] colorBuffers, RenderTargetIdentifier depthStencilBuffer,
            MaterialPropertyBlock properties = null, int shaderPassId = 0)
        {
            commandBuffer.SetRenderTarget(colorBuffers, depthStencilBuffer, 0, CubemapFace.Unknown, -1);
            commandBuffer.DrawProcedural(Matrix4x4.identity, material, shaderPassId, MeshTopology.Triangles, 3, 1, properties);
        }

        // Important: the first RenderTarget must be created with 0 depth bits!
        public static void DrawFullScreen(CommandBuffer commandBuffer, Material material,
            RenderTargetIdentifier[] colorBuffers,
            MaterialPropertyBlock properties = null, int shaderPassId = 0)
        {
            // It is currently not possible to have MRT without also setting a depth target.
            // To work around this deficiency of the CommandBuffer.SetRenderTarget() API,
            // we pass the first color target as the depth target. If it has 0 depth bits,
            // no depth target ends up being bound.
            DrawFullScreen(commandBuffer, material, colorBuffers, colorBuffers[0], properties, shaderPassId);
        }

        // Color space utilities
        public static Color ConvertSRGBToActiveColorSpace(Color color)
        {
            return (QualitySettings.activeColorSpace == ColorSpace.Linear) ? color.linear : color;
        }

        public static Color ConvertLinearToActiveColorSpace(Color color)
        {
            return (QualitySettings.activeColorSpace == ColorSpace.Linear) ? color : color.gamma;
        }

        // Unity specifics
        public static Material CreateEngineMaterial(string shaderPath)
        {
            Shader shader = Shader.Find(shaderPath);
            if (shader == null)
            {
                Debug.LogError("Cannot create required material because shader " + shaderPath + " could not be found");
                return null;
            }

            var mat = new Material(shader)
            {
                hideFlags = HideFlags.HideAndDontSave
            };
            return mat;
        }

        public static Material CreateEngineMaterial(Shader shader)
        {
            if (shader == null)
            {
                Debug.LogError("Cannot create required material because shader is null");
                return null;
            }

            var mat = new Material(shader)
            {
                hideFlags = HideFlags.HideAndDontSave
            };
            return mat;
        }

        public static bool HasFlag<T>(T mask, T flag) where T : IConvertible
        {
            return (mask.ToUInt32(null) & flag.ToUInt32(null)) != 0;
        }

        public static void Swap<T>(ref T a, ref T b)
        {
            var tmp = a;
            a = b;
            b = tmp;
        }

        public static void SetKeyword(CommandBuffer cmd, string keyword, bool state)
        {
            if (state)
                cmd.EnableShaderKeyword(keyword);
            else
                cmd.DisableShaderKeyword(keyword);
        }

        // Caution: such a call should not be use interlaced with command buffer command, as it is immediate
        public static void SetKeyword(Material m, string keyword, bool state)
        {
            if (state)
                m.EnableKeyword(keyword);
            else
                m.DisableKeyword(keyword);
        }

        public static void SelectKeyword(Material material, string keyword1, string keyword2, bool enableFirst)
        {
            material.EnableKeyword(enableFirst ? keyword1 : keyword2);
            material.DisableKeyword(enableFirst ? keyword2 : keyword1);
        }

        public static void SelectKeyword(Material material, string[] keywords, int enabledKeywordIndex)
        {
            material.EnableKeyword(keywords[enabledKeywordIndex]);

            for (int i = 0; i < keywords.Length; i++)
            {
                if (i != enabledKeywordIndex)
                    material.DisableKeyword(keywords[i]);
            }
        }

        public static void Destroy(UnityObject obj)
        {
            if (obj != null)
            {
#if UNITY_EDITOR
                if (Application.isPlaying)
                    UnityObject.Destroy(obj);
                else
                    UnityObject.DestroyImmediate(obj);
#else
                UnityObject.Destroy(obj);
#endif
            }
        }

        static IEnumerable<Type> m_AssemblyTypes;

        public static IEnumerable<Type> GetAllAssemblyTypes()
        {
            if (m_AssemblyTypes == null)
            {
                m_AssemblyTypes = AppDomain.CurrentDomain.GetAssemblies()
                    .SelectMany(t =>
                    {
                        // Ugly hack to handle mis-versioned dlls
                        var innerTypes = new Type[0];
                        try
                        {
                            innerTypes = t.GetTypes();
                        }
                        catch {}
                        return innerTypes;
                    });
            }

            return m_AssemblyTypes;
        }

        public static IEnumerable<Type> GetAllTypesDerivedFrom<T>()
        {
#if UNITY_EDITOR && UNITY_2019_2_OR_NEWER
            return UnityEditor.TypeCache.GetTypesDerivedFrom<T>();
#else
            return GetAllAssemblyTypes().Where(t => t.IsSubclassOf(typeof(T)));
#endif
        }

        public static void Destroy(params UnityObject[] objs)
        {
            if (objs == null)
                return;

            foreach (var o in objs)
                Destroy(o);
        }

        public static void SafeRelease(ComputeBuffer buffer)
        {
            if (buffer != null)
                buffer.Release();
        }

        public static Mesh CreateCubeMesh(Vector3 min, Vector3 max)
        {
            Mesh mesh = new Mesh();

            Vector3[] vertices = new Vector3[8];

            vertices[0] = new Vector3(min.x, min.y, min.z);
            vertices[1] = new Vector3(max.x, min.y, min.z);
            vertices[2] = new Vector3(max.x, max.y, min.z);
            vertices[3] = new Vector3(min.x, max.y, min.z);
            vertices[4] = new Vector3(min.x, min.y, max.z);
            vertices[5] = new Vector3(max.x, min.y, max.z);
            vertices[6] = new Vector3(max.x, max.y, max.z);
            vertices[7] = new Vector3(min.x, max.y, max.z);

            mesh.vertices = vertices;

            int[] triangles = new int[36];

            triangles[0] = 0; triangles[1] = 2; triangles[2] = 1;
            triangles[3] = 0; triangles[4] = 3; triangles[5] = 2;
            triangles[6] = 1; triangles[7] = 6; triangles[8] = 5;
            triangles[9] = 1; triangles[10] = 2; triangles[11] = 6;
            triangles[12] = 5; triangles[13] = 7; triangles[14] = 4;
            triangles[15] = 5; triangles[16] = 6; triangles[17] = 7;
            triangles[18] = 4; triangles[19] = 3; triangles[20] = 0;
            triangles[21] = 4; triangles[22] = 7; triangles[23] = 3;
            triangles[24] = 3; triangles[25] = 6; triangles[26] = 2;
            triangles[27] = 3; triangles[28] = 7; triangles[29] = 6;
            triangles[30] = 4; triangles[31] = 1; triangles[32] = 5;
            triangles[33] = 4; triangles[34] = 0; triangles[35] = 1;

            mesh.triangles = triangles;
            return mesh;
        }

        public static void DisplayUnsupportedMessage(string msg)
        {
            Debug.LogError(msg);

#if UNITY_EDITOR
            foreach (UnityEditor.SceneView sv in UnityEditor.SceneView.sceneViews)
                sv.ShowNotification(new GUIContent(msg));
#endif
        }

        public static void DisplayUnsupportedAPIMessage(string graphicAPI = null)
        {
            // If we are in the editor they are many possible targets that does not matches the current OS so we use the active build target instead
#if UNITY_EDITOR
            var buildTarget = UnityEditor.EditorUserBuildSettings.activeBuildTarget;
            string currentPlatform = buildTarget.ToString();
            graphicAPI = graphicAPI ?? UnityEditor.PlayerSettings.GetGraphicsAPIs(buildTarget).First().ToString();
#else
            string currentPlatform = SystemInfo.operatingSystem;
            graphicAPI = graphicAPI ?? SystemInfo.graphicsDeviceType.ToString();
#endif

            string msg = "Platform " + currentPlatform + " with device " + graphicAPI + " is not supported, no rendering will occur";
            DisplayUnsupportedMessage(msg);
        }

        public static void DisplayUnsupportedXRMessage()
        {
            string msg = "AR/VR devices are not supported, no rendering will occur";
            DisplayUnsupportedMessage(msg);
        }

        // Returns 'true' if "Post Processes" are enabled for the view associated with the given camera.
        public static bool ArePostProcessesEnabled(Camera camera)
        {
            bool enabled = true;

        #if UNITY_EDITOR
            if (camera.cameraType == CameraType.SceneView)
            {
                enabled = false;

                // Determine whether the "Post Processes" checkbox is checked for the current view.
                for (int i = 0; i < UnityEditor.SceneView.sceneViews.Count; i++)
                {
                    var sv = UnityEditor.SceneView.sceneViews[i] as UnityEditor.SceneView;
                    if (sv.camera == camera && sv.sceneViewState.showImageEffects)
                    {
                        enabled = true;
                        break;
                    }
                }
            }
        #endif

            return enabled;
        }

        // Returns 'true' if "Animated Materials" are enabled for the view associated with the given camera.
        public static  bool AreAnimatedMaterialsEnabled(Camera camera)
        {
            bool animateMaterials = true;

        #if UNITY_EDITOR
            animateMaterials = Application.isPlaying;

            if (camera.cameraType == CameraType.SceneView)
            {
                animateMaterials = false;

                // Determine whether the "Animated Materials" checkbox is checked for the current view.
                for (int i = 0; i < UnityEditor.SceneView.sceneViews.Count; i++) // Using a foreach on an ArrayList generates garbage ...
                {
                    var sv = UnityEditor.SceneView.sceneViews[i] as UnityEditor.SceneView;
                    if (sv.camera == camera && sv.sceneViewState.showMaterialUpdate)
                    {
                        animateMaterials = true;
                        break;
                    }
                }
            }
            else if (camera.cameraType == CameraType.Preview)
            {
                animateMaterials = false;

                // Determine whether the "Animated Materials" checkbox is checked for the current view.
                foreach (UnityEditor.MaterialEditor med in materialEditors())
                {
                    // Warning: currently, there's no way to determine whether a given camera corresponds to this MaterialEditor.
                    // Therefore, if at least one of the visible MaterialEditors is in Play Mode, all of them will play.
                    if (med.isVisible && med.RequiresConstantRepaint())
                    {
                        animateMaterials = true;
                        break;
                    }
                }
            }

            // TODO: how to handle reflection views? We don't know the parent window they are being rendered into,
            // so we don't know whether we can animate them...
            //
            // IMHO, a better solution would be:
            // A window invokes a camera render. The camera knows which window called it, so it can query its properies
            // (such as animated materials). This camera provides the space-time position. It should also be able
            // to access the rendering settings somehow. Using this information, it is then able to construct the
            // primary view with information about camera-relative rendering, LOD, time, rendering passes/features
            // enabled, etc. We then render this view. It can have multiple sub-views (shadows, reflections).
            // They inherit all the properties of the primary view, but also have the ability to override them
            // (e.g. primary cam pos and time are retained, matrices are modified, SSS and tessellation are disabled).
            // These views can then have multiple sub-views (probably not practical for games),
            // which simply amounts to a recursive call, and then the story repeats itself.
            //
            // TLDR: we need to know the caller and its status/properties to make decisions.
        #endif

            return animateMaterials;
        }

        public static bool IsSceneLightingDisabled(Camera camera)
        {
            bool disabled = false;
#if UNITY_EDITOR
            if (camera.cameraType == CameraType.SceneView)
            {
                // Determine whether the "No Scene Lighting" checkbox is checked for the current view.
                for (int i = 0; i < UnityEditor.SceneView.sceneViews.Count; i++)
                {
                    var sv = UnityEditor.SceneView.sceneViews[i] as UnityEditor.SceneView;
                    if (sv.camera == camera && !sv.sceneLighting)
                    {
                        disabled = true;
                        break;
                    }
                }
            }
#endif
            return disabled;
        }

#if UNITY_EDITOR
        static Func<List<UnityEditor.MaterialEditor>> materialEditors;

        static CoreUtils()
        {
            //quicker than standard reflection as it is compilated
            System.Reflection.FieldInfo field = typeof(UnityEditor.MaterialEditor).GetField("s_MaterialEditors", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static);
            var fieldExpression = System.Linq.Expressions.Expression.Field(null, field);
            var lambda = System.Linq.Expressions.Expression.Lambda<Func<List<UnityEditor.MaterialEditor>>>(fieldExpression);
            materialEditors = lambda.Compile();
        }
#endif

        public static bool IsSceneViewFogEnabled(Camera camera)
        {
            bool fogEnable = true;

#if UNITY_EDITOR
            if (camera.cameraType == CameraType.SceneView)
            {
                fogEnable = false;

                // Determine whether the "Animated Materials" checkbox is checked for the current view.
                for (int i = 0; i < UnityEditor.SceneView.sceneViews.Count; i++)
                {
                    var sv = UnityEditor.SceneView.sceneViews[i] as UnityEditor.SceneView;
                    if (sv.camera == camera && sv.sceneViewState.showFog)
                    {
                        fogEnable = true;
                        break;
                    }
                }
            }
#endif

            return fogEnable;
        }
    }
}