using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Threading;
using System.Runtime.InteropServices;
using Urho.Physics;
using Urho.Gui;
using Urho.Urho2D;
using Urho.Resources;

namespace Urho {
	[StructLayout (LayoutKind.Sequential)]
	public struct Ray {
		public Vector3 Origin;
		public Vector3 Direction;

		public Ray(Vector3 origin, Vector3 direction)
		{
			Origin = origin;
			Direction = Vector3.Normalize(direction);
		}

		public override bool Equals (object obj)
		{
			if (!(obj is Ray))
				return false;

			return (this == (Ray) obj);
		}

		public static bool operator == (Ray left, Ray right)
		{
			return ((left.Origin == right.Origin) && (left.Direction == right.Direction));
		}

		public static bool operator != (Ray left, Ray right)
		{
			return ((left.Origin != right.Origin) || (left.Direction != right.Direction));
		}

		public Vector3 Project (Vector3 point)
		{
			var offset = point - Origin;
			return Origin + Vector3.Dot (offset, Direction) * Direction;
		}

		public override int GetHashCode ()
		{
			return Origin.GetHashCode () + Direction.GetHashCode ();
		}

		public float Distance (Vector3 point)
		{
			var projected = Project (point);
			return (point - projected).Length;
		}

		public Vector3 ClosestPoint (Ray otherRay)
		{
			var p13 = Origin - otherRay.Origin;
			var p43 = otherRay.Direction;
			Vector3 p21 = Direction;

			float d1343 = Vector3.Dot (p13, p43);
			float d4321 = Vector3.Dot (p43, p21);
			float d1321 = Vector3.Dot (p13, p21);
			float d4343 = Vector3.Dot (p43, p43);
			float d2121 = Vector3.Dot (p21, p21);

			float d = d2121 * d4343 - d4321 * d4321;
			if (Math.Abs(d) < float.Epsilon)
				return Origin;
			float n = d1343 * d4321 - d1321 * d4343;
			float a = n / d;

			return Origin + a * Direction;
		}

		public float HitDistance (Plane plane)
		{
			float d = Vector3.Dot (plane.Normal, Direction);
			if (Math.Abs (d) >= float.Epsilon) {
				float t = -(Vector3.Dot (plane.Normal, Origin) + plane.D) / d;
				if (t >= 0.0f)
					return t;
				else
					return float.PositiveInfinity;
			} else
				return float.PositiveInfinity;
		}

	}

	[StructLayout (LayoutKind.Sequential)]
	public struct IntRect : IEquatable<IntRect> {
		public int Left, Top, Right, Bottom;
		public IntRect (int left, int top, int right, int bottom)
		{
			Left = left;
			Top = top;
			Right = right;
			Bottom = bottom;
		}

		public static bool operator ==(IntRect left, IntRect right)
		{
			return left.Equals(right);
		}

		public static bool operator !=(IntRect left, IntRect right)
		{
			return !left.Equals(right);
		}

		public bool Equals(IntRect other)
		{
			return Left == other.Left
				&& Top == other.Top
				&& Right == other.Right
				&& Bottom == other.Bottom;
		}

		public override bool Equals(object obj)
		{
			if (ReferenceEquals(null, obj)) return false;
			return obj is IntRect && Equals((IntRect)obj);
		}

		public override int GetHashCode()
		{
			int hash = 37;
			hash = hash * 43 + Left;
			hash = hash * 43 + Top;
			hash = hash * 43 + Bottom;
			hash = hash * 43 + Right;
			return hash;
		}
	}

	[StructLayout (LayoutKind.Sequential)]
	public unsafe struct TypeInfo {
		public StringHash Type;
		public UrhoString TypeName;
		public TypeInfo* BaseTypeInfo;
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct Rect : IEquatable<Rect> {
		public Vector2 Min, Max;

		public Rect (int left, int top, int right, int bottom)
		{
			Min = new Vector2 (left, top);
			Max = new Vector2 (right, bottom);
		}
		
		public Rect (Vector2 min, Vector2 max)
		{
			Min = min;
			Max = max;
		}

		public static bool operator ==(Rect left, Rect right)
		{
			return left.Equals(right);
		}

		public static bool operator !=(Rect left, Rect right)
		{
			return !left.Equals(right);
		}

		public bool Equals(Rect other)
		{
			return Min.Equals(other.Min) && Max.Equals(other.Max);
		}

		public override bool Equals(object obj)
		{
			if (ReferenceEquals(null, obj)) return false;
			return obj is Rect && Equals((Rect)obj);
		}

		public override int GetHashCode()
		{
			int hash = 37;
			hash = hash * 43 + Min.GetHashCode();
			hash = hash * 43 + Max.GetHashCode();
			return hash;
		}
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct ResourceRef {
		public StringHash Type;
		public UrhoString Name;
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct HashIteratorBase {
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct Iterator {
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct ResourceRefList {
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct BoundingBox {
		public Vector3 Min;
		public float DummyMin;
		public Vector3 Max;
		public float DummyMax;

		internal BoundingBox (bool x)
		{
			DummyMax = 0;
			DummyMin = 0;
			Min.X = float.PositiveInfinity;
			Min.Y = float.PositiveInfinity;
			Min.Z = float.PositiveInfinity;
			Max.X = float.NegativeInfinity;
			Max.Y = float.NegativeInfinity;
			Max.Z = float.NegativeInfinity;
		}
		
		public BoundingBox (float min, float max)
		{
			DummyMax = 0;
			DummyMin = 0;
			Min = new Vector3 (min, min, min);
			Max = new Vector3 (max, max, max);
		}

		public BoundingBox (Vector3 min, Vector3 max)
		{
			DummyMax = 0;
			DummyMin = 0;
			Min = min;
			Max = max;
		}

		public void Merge (Vector3 point)
		{
			if (point.X < Min.X)
				Min.X = point.X;
			if (point.Y < Min.Y)
				Min.Y = point.Y;
			if (point.Z < Min.Z)
				Min.Z = point.Z;
			if (point.X > Max.X)
				Max.X = point.X;
			if (point.Y > Max.Y)
				Max.Y = point.Y;
			if (point.Z > Max.Z)
				Max.Z = point.Z;
		}

		public void Merge (BoundingBox box)
		{
			if (box.Min.X < Min.X)
				Min.X = box.Min.X;
			if (box.Min.Y < Min.Y)
				Min.Y = box.Min.Y;
			if (box.Min.Z < Min.Z)
				Min.Z = box.Min.Z;
			if (box.Max.X > Max.X)
				Max.X = box.Max.X;
			if (box.Max.Y > Max.Y)
				Max.Y = box.Max.Y;
			if (box.Max.Z > Max.Z)
				Max.Z = box.Max.Z;			
		}

		public void Merge (Vector3 [] points)
		{
			if (points == null)
				throw new ArgumentNullException (nameof (points));

			foreach (var p in points)
				Merge (p);
		}

		public void Merge (Frustum frustum)
		{
			if (frustum == null)
				throw new ArgumentNullException (nameof (frustum));
			foreach (var p in frustum.Vertices)
				Merge (p);
		}
		
		public BoundingBox (Vector3 [] points) : this (true)
		{
			Merge (points);
		}

		public BoundingBox (Rect rect) : this (new Vector3 (rect.Min.X, rect.Min.Y, 0), new Vector3 (rect.Max.X, rect.Max.Y, 0))
		{
		}

		public BoundingBox (Frustum frustum) : this (true)
		{
			Merge (frustum);
		}
		
		public bool Defined ()
		{
			return Min.X != float.PositiveInfinity;
		}

		public Vector3 Center {
			get {
				return (Max + Min) * 0.5f;
			}
		}

		public Vector3 Size {
			get {
				return Max - Min;
			}
		}
		public Vector3 HalfSize {
			get {
				return (Max - Min)*0.5f;
			}
		}
			
		public Intersection IsInside (Vector3 point)
		{
			if (point.X < Min.X || point.X > Max.X ||
				point.Y < Min.Y || point.Y > Max.Y ||
				point.Z < Min.Z || point.Z > Max.Z)
				return Intersection.Outside;
			return Intersection.Inside;
		}

		public Intersection IsInside (BoundingBox box)
		{
			if (box.Max.X < Min.X || box.Min.X > Max.X || 
				box.Max.Y < Min.Y || box.Min.Y > Max.Y ||
				box.Max.Z < Min.Z || box.Min.Z > Max.Z)
				return Intersection.Outside;
			else if (box.Min.X < Min.X || box.Max.X > Max.X || 
					 box.Min.Y < Min.Y || box.Max.Y > Max.Y ||
					 box.Min.Z < Min.Z || box.Max.Z > Max.Z)
				return Intersection.Intersects;
			else
				return Intersection.Inside;
		}

		public Intersection IsInsideFast (BoundingBox box)
		{
			if (box.Max.X < Min.X || box.Min.X > Max.X || 
				box.Max.Y < Min.Y || box.Min.Y > Max.Y ||
				box.Max.Z < Min.Z || box.Min.Z > Max.Z)
				return Intersection.Outside;
			else
				return Intersection.Inside;
		}

		public BoundingBox Clip (BoundingBox box)
		{
			return new BoundingBox (new Vector3 (Math.Max (box.Min.X, Min.X),
								 Math.Max (box.Min.Y, Min.Y),
								 Math.Max (box.Min.Z, Min.Z)),
						new Vector3 (Math.Min (box.Max.X, Max.X),
								 Math.Min (box.Max.Y, Max.Y),
								 Math.Min (box.Max.Z, Max.Z)));
		}
	}

	[StructLayout(LayoutKind.Explicit)]
	public struct AnimationTriggerPoint {
		[FieldOffset(0)]
		public float Time;
		[FieldOffset(8)]
		public Variant Variant;
	}

	[StructLayout(LayoutKind.Sequential)]
	public unsafe struct VariantValue
	{
		IntPtr Storage1;
		IntPtr Storage2;
		IntPtr Storage3;
		IntPtr Storage4;
	}

	[StructLayout(LayoutKind.Explicit)]
	public struct Variant {
		[FieldOffset(0)]
		public VariantType Type;
		[FieldOffset(8)]
		public VariantValue Value;
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct Matrix3x4 {
		public float m00;
		public float m01;
		public float m02;
		public float m03;
		public float m10;
		public float m11;
		public float m12;
		public float m13;
		public float m20;
		public float m21;
		public float m22;
		public float m23;

		public static readonly Matrix3x4 Identity = new Matrix3x4 {m00 = 1, m11 = 1, m22 = 1};
		public static readonly Matrix3x4 Zero = new Matrix3x4 ();

		public Matrix3x4(
			float v00, float v01, float v02, float v03,
			float v10, float v11, float v12, float v13,
			float v20, float v21, float v22, float v23)
		{
			m00 = v00; m01 = v01; m02 = v02; m03 = v03;
			m10 = v10; m11 = v11; m12 = v12; m13 = v13;
			m20 = v20; m21 = v21; m22 = v22; m23 = v23;
		}

		public Matrix3x4(Vector3 row0, Vector3 row1, Vector3 row2, Vector3 row3)
		{
			m00 = row0.X; m10 = row0.Y; m20 = row0.Z;
			m01 = row1.X; m11 = row1.Y; m21 = row1.Z;
			m02 = row2.X; m12 = row2.Y; m22 = row2.Z;
			m03 = row3.X; m13 = row3.Y; m23 = row3.Z;
		}

		public Matrix3x4 Inverse()
		{
			float det = m00 * m11 * m22 +
				m10 * m21 * m02 +
				m20 * m01 * m12 -
				m20 * m11 * m02 -
				m10 * m01 * m22 -
				m00 * m21 * m12;

			float invDet = 1.0f / det;
			Matrix3x4 ret;

			ret.m00 = (m11 * m22 - m21 * m12) * invDet;
			ret.m01 = -(m01 * m22 - m21 * m02) * invDet;
			ret.m02 = (m01 * m12 - m11 * m02) * invDet;
			ret.m03 = -(m03 * ret.m00 + m13 * ret.m01 + m23 * ret.m02);
			ret.m10 = -(m10 * m22 - m20 * m12) * invDet;
			ret.m11 = (m00 * m22 - m20 * m02) * invDet;
			ret.m12 = -(m00 * m12 - m10 * m02) * invDet;
			ret.m13 = -(m03 * ret.m10 + m13 * ret.m11 + m23 * ret.m12);
			ret.m20 = (m10 * m21 - m20 * m11) * invDet;
			ret.m21 = -(m00 * m21 - m20 * m01) * invDet;
			ret.m22 = (m00 * m11 - m10 * m01) * invDet;
			ret.m23 = -(m03 * ret.m20 + m13 * ret.m21 + m23 * ret.m22);

			return ret;
		}
		
		public static Matrix4 operator *(Matrix4 left, Matrix3x4 rhs)
		{
			return new Matrix4(
				left.M11 * rhs.m00 + left.M12 * rhs.m10 + left.M13 * rhs.m20,
				left.M11 * rhs.m01 + left.M12 * rhs.m11 + left.M13 * rhs.m21,
				left.M11 * rhs.m02 + left.M12 * rhs.m12 + left.M13 * rhs.m22,
				left.M11 * rhs.m03 + left.M12 * rhs.m13 + left.M13 * rhs.m23 + left.M14,
				left.M21 * rhs.m00 + left.M22 * rhs.m10 + left.M23 * rhs.m20,
				left.M21 * rhs.m01 + left.M22 * rhs.m11 + left.M23 * rhs.m21,
				left.M21 * rhs.m02 + left.M22 * rhs.m12 + left.M23 * rhs.m22,
				left.M21 * rhs.m03 + left.M22 * rhs.m13 + left.M23 * rhs.m23 + left.M24,
				left.M31 * rhs.m00 + left.M32 * rhs.m10 + left.M33 * rhs.m20,
				left.M31 * rhs.m01 + left.M32 * rhs.m11 + left.M33 * rhs.m21,
				left.M31 * rhs.m02 + left.M32 * rhs.m12 + left.M33 * rhs.m22,
				left.M31 * rhs.m03 + left.M32 * rhs.m13 + left.M33 * rhs.m23 + left.M34,
				left.M41 * rhs.m00 + left.M42 * rhs.m10 + left.M43 * rhs.m20,
				left.M41 * rhs.m01 + left.M42 * rhs.m11 + left.M43 * rhs.m21,
				left.M41 * rhs.m02 + left.M42 * rhs.m12 + left.M43 * rhs.m22,
				left.M41 * rhs.m03 + left.M42 * rhs.m13 + left.M43 * rhs.m23 + left.M44
			);
		}
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct Color {
		public float R, G, B, A;

		public Color (float r = 1f, float g = 1f, float b = 1f, float a = 1f)
		{
			R = r;
			G = g;
			B = b;
			A = a;
		}

		public Color (Color source)
		{
			R = source.R;
			G = source.G;
			B = source.B;
			A = source.A;
		}

		public Color (Color source, float alpha)
		{
			R = source.R;
			G = source.G;
			B = source.B;
			A = alpha;
		}

		public static Color White = new Color (1, 1, 1);
		public static Color Gray = new Color (0.5f, 0.5f, 0.5f);
		public static Color Black = new Color (0.0f, 0.0f, 0.0f);
		public static Color Red = new Color (1.0f, 0.0f, 0.0f);
		public static Color Green = new Color (0.0f, 1.0f, 0.0f);
		public static Color Blue = new Color (0.0f, 0.0f, 1.0f);
		public static Color Cyan = new Color (0.0f, 1.0f, 1.0f);
		public static Color Magenta = new Color (1.0f, 0.0f, 1.0f);
		public static Color Yellow = new Color (1.0f, 1.0f, 0.0f);
		public static Color Transparent = new Color (0.0f, 0.0f, 0.0f, 0.0f);

		public static Color FromByteFormat(byte r, byte g, byte b, byte a)
		{
			return new Color(r / 255f, g / 255f, b / 255f, a / 255f);
		}
		
		public static Color FromHex(string hex)
		{
			hex = hex.Replace("#", string.Empty);
			if (hex.Length == 6)
				hex = "FF" + hex;
			byte a = (byte)(Convert.ToUInt32(hex.Substring(0, 2), 16));
			byte r = (byte)(Convert.ToUInt32(hex.Substring(2, 2), 16));
			byte g = (byte)(Convert.ToUInt32(hex.Substring(4, 2), 16));
			byte b = (byte)(Convert.ToUInt32(hex.Substring(6, 2), 16));
			return FromByteFormat(r, g, b, a);
		}

		public uint ToUInt()
		{
			uint r = (uint)MathHelper.Clamp(((int)(R * 255.0f)), 0, 255);
			uint g = (uint)MathHelper.Clamp(((int)(G * 255.0f)), 0, 255);
			uint b = (uint)MathHelper.Clamp(((int)(B * 255.0f)), 0, 255);
			uint a = (uint)MathHelper.Clamp(((int)(A * 255.0f)), 0, 255);
			return (a << 24) | (b << 16) | (g << 8) | r;
		}

		public static Color operator +(Color left, Color right)
		{
			left.A = MathHelper.Clamp(left.A + right.A, 0, 1);
			left.R = MathHelper.Clamp(left.R + right.R, 0, 1);
			left.G = MathHelper.Clamp(left.G + right.G, 0, 1);
			left.B = MathHelper.Clamp(left.B + right.B, 0, 1);
			return left;
		}

		public static Color operator -(Color left, Color right)
		{
			left.A = MathHelper.Clamp(left.A - right.A, 0, 1);
			left.R = MathHelper.Clamp(left.R - right.R, 0, 1);
			left.G = MathHelper.Clamp(left.G - right.G, 0, 1);
			left.B = MathHelper.Clamp(left.B - right.B, 0, 1);
			return left;
		}

		public static Color operator *(Color left, float value)
		{
			left.A = MathHelper.Clamp(left.A * value, 0, 1);
			left.R = MathHelper.Clamp(left.R * value, 0, 1);
			left.G = MathHelper.Clamp(left.G * value, 0, 1);
			left.B = MathHelper.Clamp(left.B * value, 0, 1);
			return left;
		}

		public static bool operator ==(Color left, Color right)
		{
			return left.Equals(right);
		}

		public static bool operator !=(Color left, Color right)
		{
			return !left.Equals(right);
		}

		public bool Equals(Color other)
		{
			return R.Equals(other.R) && G.Equals(other.G) && B.Equals(other.B) && A.Equals(other.A);
		}

		public override bool Equals(object obj)
		{
			if (ReferenceEquals(null, obj)) return false;
			return obj is Color && Equals((Color)obj);
		}

		public override int GetHashCode()
		{
			unchecked
			{
				var hashCode = R.GetHashCode();
				hashCode = (hashCode * 397) ^ G.GetHashCode();
				hashCode = (hashCode * 397) ^ B.GetHashCode();
				hashCode = (hashCode * 397) ^ A.GetHashCode();
				return hashCode;
			}
		}

		public override string ToString()
		{
			return $"r:{R}, g:{G}, b:{B}, a:{A}";
		}

		public static explicit operator Color(Vector3 vector) => new Color(vector.X, vector.Y, vector.Z);
		public static explicit operator Vector3(Color color) => new Vector3(color.R, color.G, color.B);
		public static explicit operator Color(Vector4 vector) => new Color(vector.X, vector.Y, vector.Z, vector.W);
		public static explicit operator Vector4(Color color) => new Vector4(color.R, color.G, color.B, color.A);
	}
	
	[StructLayout (LayoutKind.Sequential)]
	public struct WeakPtr {
		IntPtr ptr;
		IntPtr refCountPtr;

		public T GetUrhoObject<T>() where T : UrhoObject => Runtime.LookupObject<T>(ptr);
		public T GetRefCounted<T>() where T : RefCounted => Runtime.LookupRefCounted<T>(ptr);
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct TouchState {
		public int TouchID;
		public IntVector2 Position, LastPosition, Delta;
		public float Pressure;

		WeakPtr touchedElementPtr;
		public UIElement TouchedElement => touchedElementPtr.GetUrhoObject<UIElement>();
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct ColorFrame {
		public Color Color;
		public float Time;
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct JoystickState {
		public IntPtr JoystickPtr;
		public IntPtr JoystickIdPtr;
		public IntPtr ControllerPtr;

		IntPtr screenJoystickPtr;
		public UIElement ScreenJoystick => Runtime.LookupObject<UIElement>(screenJoystickPtr);

		public UrhoString Name;
		public VectorBase Buttons;
		public VectorBase ButtonPress;
		public VectorBase Axes;
		public VectorBase Hats;

		public float GetAxisPosition(int position)
		{
			if (position >= Axes.Size) 
				return 0;

			return Axes.Buffer.ReadSingle(position * sizeof(float));
		}

		public byte GetButtonDown(int position)
		{
			if (position >= Buttons.Size)
				return 0;

			return Marshal.ReadByte(Buttons.Buffer, position * sizeof(byte));
		}

		public byte GetButtonPress(int position)
		{
			if (position >= ButtonPress.Size)
				return 0;

			return Marshal.ReadByte(ButtonPress.Buffer, position * sizeof(byte));
		}

		public int GetHatPosition(int position)
		{
			if (position >= Hats.Size)
				return 0;
			
			return Marshal.ReadInt32(Hats.Buffer, position * sizeof(int));
		}
	}

	[StructLayout(LayoutKind.Sequential)]
	public struct VectorBase {
		public uint Size;
		public uint Capacity;
		public IntPtr Buffer;
	}

	[StructLayout(LayoutKind.Sequential)]
	public struct SDL_Event {
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct TextureFrame {
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct LightBatchQueue {
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct Bone {
		public UrhoString Name;
		public int NameHash;
		public uint ParentIndex;
		public Vector3 InitialPosition;
		public Quaternion InitialRotation;
		public Vector3 InitialScale;
		public Matrix3x4 OffsetMatrix;

		byte animated; //bool is not blittable.
		public bool Animated { get { return animated != 0; } set { animated = (byte)(value ? 1 : 0); } }

		public byte CollisionMask;
		public float Radius;
		public BoundingBox BoundingBox;
		WeakPtr Node;
	}

	public unsafe class BoneWrapper
	{
		readonly object objHolder;
		readonly Bone* b;

		public BoneWrapper(object objHolder, Bone* bone)
		{
			this.objHolder = objHolder;
			this.b = bone;
		}

		public UrhoString Name { get { return b->Name; } set { b->Name = value; } }
		public int NameHash { get { return b->NameHash; } set { b->NameHash = value; } }
		public uint ParentIndex { get { return b->ParentIndex; } set { b->ParentIndex = value; } }
		public Vector3 InitialPosition { get { return b->InitialPosition; } set { b->InitialPosition = value; } }
		public Quaternion InitialRotation { get { return b->InitialRotation; } set { b->InitialRotation = value; } }
		public Vector3 InitialScale { get { return b->InitialScale; } set { b->InitialScale = value; } }
		public Matrix3x4 OffsetMatrix { get { return b->OffsetMatrix; } set { b->OffsetMatrix = value; } }
		public bool Animated { get { return b->Animated; } set { b->Animated = value; } }
		public byte CollisionMask { get { return b->CollisionMask; } set { b->CollisionMask = value; } }
		public float Radius { get { return b->Radius; } set { b->Radius = value; } }
		public BoundingBox BoundingBox { get { return b->BoundingBox; } set { b->BoundingBox = value; } }
	}

	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout(LayoutKind.Sequential)]
	public struct RayQueryResult {
		public Vector3 Position;
		public Vector3 Normal;
		public Vector2 TextureUV;
		public float Distance;

		IntPtr drawablePtr;
		public Drawable Drawable => Runtime.LookupObject<Drawable>(drawablePtr);

		IntPtr nodePtr;
		public Node Node => Runtime.LookupObject<Node>(nodePtr);

		public uint SubObject;
	}

	[StructLayout (LayoutKind.Sequential)]
	public unsafe struct RenderPathCommand {
		public UrhoString Tag;
		public RenderCommandType Type;
		public RenderCommandSortMode SortMode;
		public UrhoString Pass;
		public uint PassIndex;
		public UrhoString Metadata;
		public UrhoString VertexShaderName;
		public UrhoString PixelShaderName;
		public UrhoString VertexShaderDefines;
		public UrhoString PixelShaderDefines;

		//Marshalling  String textureNames_[16]
		public UrhoString TextureName0;
		public UrhoString TextureName1;
		public UrhoString TextureName2;
		public UrhoString TextureName3;
		public UrhoString TextureName4;
		public UrhoString TextureName5;
		public UrhoString TextureName6;
		public UrhoString TextureName7;

#if !IOS && !ANDROID
		public UrhoString TextureName8;
		public UrhoString TextureName9;
		public UrhoString TextureName10;
		public UrhoString TextureName11;
		public UrhoString TextureName12;
		public UrhoString TextureName13;
		public UrhoString TextureName14;
		public UrhoString TextureName15;
#endif

		public RenderPathCommand(RenderCommandType type)
		{
			BlendMode = BlendMode.Replace;
			Enabled = 1;
			UseLitBase = 1;
			Type = type;

			//default values:
			Tag = default(UrhoString);
			SortMode = RenderCommandSortMode.Fronttoback;
			Pass = default(UrhoString);
			PassIndex = 0;
			Metadata = default(UrhoString);
			PixelShaderName = default(UrhoString);
			VertexShaderName = default(UrhoString);
			PixelShaderDefines = default(UrhoString);
			VertexShaderDefines = default(UrhoString);
			TextureName0 = default(UrhoString);
			TextureName1 = default(UrhoString);
			TextureName2 = default(UrhoString);
			TextureName3 = default(UrhoString);
			TextureName4 = default(UrhoString);
			TextureName5 = default(UrhoString);
			TextureName6 = default(UrhoString);
			TextureName7 = default(UrhoString);
#if !IOS && !ANDROID
			TextureName8 = default(UrhoString);
			TextureName9 = default(UrhoString);
			TextureName10 = default(UrhoString);
			TextureName11 = default(UrhoString);
			TextureName12 = default(UrhoString);
			TextureName13 = default(UrhoString);
			TextureName14 = default(UrhoString);
			TextureName15 = default(UrhoString);
#endif
			ShaderParameters = default(HashBase);
			Outputs = default(VectorBase);
			DepthStencilName = default(UrhoString);
			ClearFlags = 0;
			ClearColor = default(Color);
			ClearDepth = 0;
			ClearStencil = 0;
			UseFogColor = 0;
			MarkToStencil = 0;
			VertexLights = 0;
			EventName = default(UrhoString);
		}

		public void SetTextureName(TextureUnit unit, string name)
		{
			UrhoString nameStr = new UrhoString(name);
			switch (unit)
			{
				case TextureUnit.Diffuse:
					TextureName0 = nameStr;
					break;
				case TextureUnit.Normal:
					TextureName1 = nameStr;
					break;
				case TextureUnit.Specular:
					TextureName2 = nameStr;
					break;
				case TextureUnit.Emissive:
					TextureName3 = nameStr;
					break;
				case TextureUnit.Environment:
					TextureName4 = nameStr;
					break;
				case TextureUnit.Volumemap:
					TextureName5 = nameStr;
					break;
				case TextureUnit.Custom1:
					TextureName6 = nameStr;
					break;
				case TextureUnit.Custom2:
					TextureName7 = nameStr;
					break;

#if !IOS && !ANDROID
				case TextureUnit.Lightramp:
					TextureName8 = nameStr;
					break;
				case TextureUnit.Lightshape:
					TextureName9 = nameStr;
					break;
				case TextureUnit.Shadowmap:
					TextureName10 = nameStr;
					break;
				case TextureUnit.Faceselect:
					TextureName11 = nameStr;
					break;
				case TextureUnit.Indirection:
					TextureName12 = nameStr;
					break;
				case TextureUnit.Depthbuffer:
					TextureName13 = nameStr;
					break;
				case TextureUnit.Lightbuffer:
					TextureName14 = nameStr;
					break;
				case TextureUnit.Zone:
					TextureName15 = nameStr;
					break;
#endif

				default:
					throw new InvalidOperationException("Invalid texture unit");
			}
		}

		// TODO: Surface more members via SharpieBinder

		[DllImport(Consts.NativeImport, CallingConvention = CallingConvention.Cdecl)]
		static extern void RenderPathCommand_SetShaderParameter(ref RenderPathCommand rpc, string parameter, float value);

		[DllImport(Consts.NativeImport, CallingConvention = CallingConvention.Cdecl)]
		static extern void RenderPathCommand_SetOutput(ref RenderPathCommand rpc, int index, string name);

		public void SetShaderParameter(string parameter, float value) =>
			RenderPathCommand_SetShaderParameter(ref this, parameter, value);

		public void SetOutput(int index, string name) =>
			RenderPathCommand_SetOutput(ref this, index, name);

		public HashBase ShaderParameters;
		public VectorBase Outputs;
		public UrhoString DepthStencilName;
		public uint ClearFlags;
		public Color ClearColor;
		public float ClearDepth;
		public uint ClearStencil;
		public BlendMode BlendMode;
		public byte Enabled;
		public byte UseFogColor;
		public byte MarkToStencil;
		public byte UseLitBase;
		public byte VertexLights;
		public UrhoString EventName;
	}

	[StructLayout(LayoutKind.Sequential)]
	public struct VertexElement
	{
		public VertexElementType Type;
		/// <summary>
		/// Semantic of element.
		/// </summary>
		VertexElementSemantic Semantic;
		/// <summary>
		/// Semantic index of element, for example multi-texcoords.
		/// </summary>
		public byte Index;
		/// <summary>
		/// Per-instance flag.
		/// </summary>
		public byte PerInstance;
		/// <summary>
		/// Offset of element from vertex start. Filled by VertexBuffer once the vertex declaration is built.
		/// </summary>
		public uint Offset;
	}


	[StructLayout(LayoutKind.Sequential)]
	public struct HashBase {
		public IntPtr Head;
		public IntPtr Tail;
		public IntPtr Ptrs;
		public IntPtr Allocator;
	}

	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout (LayoutKind.Sequential)]
	public struct GraphicsImpl {
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct FontGlyph {
		public short X, Y, TexWidth, TexHeight;
		public float Width, Height, OffsetX, OffsetY, AdvanceX;
		public int Page;
		byte used;
		public bool Used { get { return used != 0; } set { used = (byte) (value ? 1 : 0); }}
		
	}
	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout (LayoutKind.Sequential)]
	public struct RandomAccessIterator {
	}
	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout (LayoutKind.Sequential)]
	public struct ModelMorph {
	}
	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout (LayoutKind.Sequential)]
	public struct Octant {
	}
	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout (LayoutKind.Sequential)]
	public struct CompressedLevel {
		public IntPtr ImageData;
		public CompressedFormat Format;
		public int Width, Height, Depth;
		public uint BlockSize, DataSize, RowSize, RowCount;
	}

	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout (LayoutKind.Sequential)]
	public struct Billboard {
		public Vector3 Position;
		public Vector2 Size;
		public Rect Uv;
		public Color Color;
		public float Rotation;
		public Vector3 Direction;

		byte enabled; //bool is not blittable.
		public bool Enabled { get { return enabled != 0; } set { enabled = (byte)(value ? 1 : 0); } }

		public float SortDistance;
		public float ScreenScaleFactor;
	}
	
	public unsafe class BillboardWrapper
	{
		readonly object bbHolder;
		readonly Billboard* bb;

		public BillboardWrapper(object bbHolder, Billboard* bb)
		{
			this.bbHolder = bbHolder;
			this.bb = bb;
		}

		public Vector3 Position { get { return bb->Position; } set { bb->Position = value; } }
		public Vector2 Size { get { return bb->Size; } set { bb->Size = value; } }
		public Rect Uv { get { return bb->Uv; } set { bb->Uv = value; } }
		public Color Color { get { return bb->Color; } set { bb->Color = value; } }
		public float Rotation { get { return bb->Rotation; } set { bb->Rotation = value; } }
		public bool Enabled { get { return bb->Enabled; } set { bb->Enabled = value; } }
		public float SortDistance { get { return bb->SortDistance; } set { bb->SortDistance = value; } }
	}

	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout (LayoutKind.Sequential)]
	public struct AnimationTrack {
	}

	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout (LayoutKind.Sequential)]
	public struct CustomGeometryVertex
	{
		public Vector3 Position;
		public Vector3 Normal;
		public uint Color;
		public Vector2 TexCoord;
		public Vector4 Tangent;
	}

	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout (LayoutKind.Sequential)]
	public struct NetworkState {
	}

	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout (LayoutKind.Sequential)]
	public struct ComponentReplicationState {
	}

	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout (LayoutKind.Sequential)]
	public struct ShaderParameter {
	}

	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout (LayoutKind.Sequential)]
	public struct UrhoString
	{
		public uint Length;
		public uint Capacity;
		public IntPtr Buffer;

		public UrhoString(string str)
		{
			Buffer = Marshal.StringToHGlobalAnsi(str);
			Length = (uint)str.Length;
			Capacity = (uint)Math.Max(8, str.Length) + 1;
		}

		public override string ToString()
		{
			if (Length > 0 && Buffer != IntPtr.Zero)
				return Marshal.PtrToStringAnsi(Buffer, (int)Length);
			return string.Empty;
		}

		public static implicit operator string(UrhoString s)  // implicit digit to byte conversion operator
		{
			return s.ToString();
		}

		public static explicit operator UrhoString(string s)  // explicit byte to digit conversion operator
		{
			return new UrhoString(s);
		}
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct BiasParameters {
		public float ConstantBias;
		public float SlopeScaleBias;
		public float NormalOffset;

		public BiasParameters (float constantBias, float slopeScaleBias, float normalOffset = 0.0f)
		{
			ConstantBias = constantBias;
			SlopeScaleBias = slopeScaleBias;
			NormalOffset = normalOffset;
		}
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct CascadeParameters {
		public float Split1, Split2, Split3, Split4;
		public float FadeStart;
		public float BiasAutoAdjust;

		public CascadeParameters (float split1, float split2, float split3, float split4, float fadeStart, float biasAutoAdjust = 1f)
		{
			Split1 = split1;
			Split2 = split2;
			Split3 = split3;
			Split4 = split4;
			FadeStart = fadeStart;
			BiasAutoAdjust = biasAutoAdjust;
		}
	}

	[StructLayout (LayoutKind.Sequential)]
	public struct FocusParameters {
		public byte Focus;
		public byte NonUniform;
		public byte AutoSize;
		public float Quantize;
		public float MinView;
	}
}


namespace Urho.IO {
	[StructLayout (LayoutKind.Sequential)]
	public struct PackageEntry {
		public int Offset, Size, Checksum;
	}
}

namespace Urho.Urho2D {
	// DEBATABLE: maybe we should let the binder handle it?
	[StructLayout(LayoutKind.Sequential)]
	public struct TileMapInfo2D {
		public Orientation2D Orientation;
		public int Width;
		public int Height;
		public float TileWidth;
		public float TileHeight;

		//calculated properties:
		public float MapWidth => Width * TileWidth;
		public float MapHeight
		{
			get
			{
				if (Orientation == Orientation2D.Staggered)
					return (Height + 1) * 0.5f * TileHeight;
				return Height * TileHeight;
			}
		}
	}
}

namespace Urho.Navigation {

	[StructLayout(LayoutKind.Sequential)]
	public struct dtQueryFilter {
		//public float[] AreaCost;     // Cost per area type. (Used by default implementation.)
		//public ushort IncludeFlags;  // Flags for polygons that can be visited. (Used by default implementation.)
		//public ushort ExcludeFlags;  // Flags for polygons that should not be visted. (Used by default implementation.)
	}

	[StructLayout(LayoutKind.Sequential)]
	public struct CrowdObstacleAvoidanceParams {
		public float VelBias;
		public float WeightDesVel;
		public float WeightCurVel;
		public float WeightSide;
		public float WeightToi;
		public float HorizTime;
		public byte GridSize;
		public byte AdaptiveDivs;
		public byte AdaptiveRings;
		public byte AdaptiveDepth;
	};

}

namespace Urho.Physics {
	[StructLayout(LayoutKind.Sequential)]
	public struct PhysicsRaycastResult {
		public Vector3 Position;
		public Vector3 Normal;
		public float Distance;
		public float HitFraction;

		IntPtr bodyPtr;
		public RigidBody Body => Runtime.LookupObject<RigidBody>(bodyPtr);
	}

}

namespace Urho.Resources {
	[StructLayout (LayoutKind.Sequential)]
	public struct XPathResultSet {
	}
}

namespace Urho.Network {

	[StructLayout (LayoutKind.Sequential)]
	public struct ReplicationState {
		IntPtr connection;
		public Connection Connection => Runtime.LookupObject<Connection> (connection);
	}

	[StructLayout (LayoutKind.Sequential)]
	public unsafe struct DirtyBits {
		public fixed byte Data [8];
		public byte Count;
	}
	
	[StructLayout (LayoutKind.Sequential)]
	public struct NodeReplicationState {
	}
}