/******************************************************************************
	libx42.net - skinned vertex animation library (.NET API)
	Copyright (C) 2007 HermitWorks Entertainment Corporation

	This program is free software; you can redistribute it and/or modify it
	under the terms of the GNU General Public License as published by the Free
	Software Foundation; either version 2 of the License, or (at your option)
	any later version.

	This program is distributed in the hope that it will be useful, but
	WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
	or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
	for more details.

	You should have received a copy of the GNU General Public License along
	with this program; if not, write to the
	
		Free Software Foundation, Inc.
		51 Franklin Street, Fifth Floor
		Boston, MA  02110-1301, USA.
******************************************************************************/

#pragma once

#include "Vector.h"
#include "DataStream.h"

namespace Libx42
{

[::System::Runtime::InteropServices::StructLayout(
	::System::Runtime::InteropServices::LayoutKind::Explicit,
	Size = 32 )]
public value struct VertexPosition
{
public:
	[::System::Runtime::InteropServices::FieldOffset( 0 )]
	Math::Vector3	Position;
	[::System::Runtime::InteropServices::FieldOffset( 12 )]
	
	Byte			BlendIndex0;
	[::System::Runtime::InteropServices::FieldOffset( 13 )]
	Byte			BlendIndex1;
	[::System::Runtime::InteropServices::FieldOffset( 14 )]
	Byte			BlendIndex2;
	[::System::Runtime::InteropServices::FieldOffset( 15 )]
	Byte			BlendIndex3;

	[::System::Runtime::InteropServices::FieldOffset( 16 )]
	float			BlendWeight0;
	[::System::Runtime::InteropServices::FieldOffset( 20 )]
	float			BlendWeight1;
	[::System::Runtime::InteropServices::FieldOffset( 24 )]
	float			BlendWeight2;
	[::System::Runtime::InteropServices::FieldOffset( 28 )]
	float			BlendWeight3;

	[::System::Runtime::InteropServices::FieldOffset( 0 )]
	literal int NumBlendWeignts = 4;

	bool GetBlend( int index,
		[::System::Runtime::InteropServices::Out] int %influenceIndex,
		[::System::Runtime::InteropServices::Out] float %weightValue )
	{
		switch( index )
		{
		case 0:
			influenceIndex = BlendIndex0;
			weightValue = BlendWeight0;
			break;

		case 1:
			influenceIndex = BlendIndex1;
			weightValue = BlendWeight1;
			break;

		case 2:
			influenceIndex = BlendIndex2;
			weightValue = BlendWeight2;
			break;

		case 3:
			influenceIndex = BlendIndex3;
			weightValue = BlendWeight3;
			break;

		default:
			throw gcnew ArgumentOutOfRangeException( "index" );
		}

		return weightValue != 0;
	}

	bool Equals( VertexPosition vp ) new;
	virtual bool Equals( Object ^obj ) override;

	static bool operator == ( VertexPosition a, VertexPosition b )
	{
		return a.Equals( b );
	}
	static bool operator != ( VertexPosition a, VertexPosition b )
	{
		return !a.Equals( b );
	}
};

[::System::Runtime::InteropServices::StructLayout(
	::System::Runtime::InteropServices::LayoutKind::Explicit,
	Size = 16 )]
public value struct VertexNormal
{
public:
	[::System::Runtime::InteropServices::FieldOffset( 0 )]
	Math::Vector3	Normal;

	bool Equals( VertexNormal vp ) new;
	virtual bool Equals( Object ^obj ) override;

	static bool operator == ( VertexNormal a, VertexNormal b )
	{
		return a.Equals( b );
	}
	static bool operator != ( VertexNormal a, VertexNormal b )
	{
		return !a.Equals( b );
	}
};

[::System::Runtime::InteropServices::StructLayout(
	::System::Runtime::InteropServices::LayoutKind::Explicit,
	Size = 32 )]
public value struct VertexTangentBasis
{
public:	
	[::System::Runtime::InteropServices::FieldOffset( 0 )]
	Math::Vector3	Tangent;
	[::System::Runtime::InteropServices::FieldOffset( 12 )]
	float NormalFactor;
	[::System::Runtime::InteropServices::FieldOffset( 16 )]
	Math::Vector3	Binormal;

	bool Equals( VertexTangentBasis vp ) new;
	virtual bool Equals( Object ^obj ) override;

	static bool operator == ( VertexTangentBasis a, VertexTangentBasis b )
	{
		return a.Equals( b );
	}
	static bool operator != ( VertexTangentBasis a, VertexTangentBasis b )
	{
		return !a.Equals( b );
	}
};

[::System::Runtime::InteropServices::StructLayout(
	::System::Runtime::InteropServices::LayoutKind::Explicit,
	Size = 4 )]
public value struct VertexColor
{
public:
	[::System::Runtime::InteropServices::FieldOffset( 0 )]
	Byte R;
	[::System::Runtime::InteropServices::FieldOffset( 1 )]
	Byte G;
	[::System::Runtime::InteropServices::FieldOffset( 2 )]
	Byte B;
	[::System::Runtime::InteropServices::FieldOffset( 3 )]
	Byte A;

	bool Equals( VertexColor cl ) new;
	virtual bool Equals( Object ^obj ) override;

	static bool operator == ( VertexColor a, VertexColor b )
	{
		return a.Equals( b );
	}

	static bool operator != ( VertexColor a, VertexColor b )
	{
		return !a.Equals( b );
	}
};

ref class Model;
ref class Group;

public ref class VertexData
{
public:
	property Model^ Owner { Model^ get( void ) { return owner; } }

	/// <summary>
	/// Gets this vertex data chunk's starting index in the model's vertices array.
	/// </summary>
	property int Offset { int get( void ) { return offset; } }
	/// <summary>
	/// Gets the number of vertices in this data chunk.
	/// </summary>
	property int Count { int get( void ) { return count; } }

	property DataStream< VertexPosition >^ PositionStream { DataStream< VertexPosition >^ get( void ) { return vp; } }
	property DataStream< VertexNormal >^ NormalStream { DataStream< VertexNormal >^ get( void ) { return vn; } }
	property DataStream< VertexTangentBasis >^ TangentBasisStream { DataStream< VertexTangentBasis >^ get( void ) { return vt; } }
	property DataStream< Math::Vector2 >^ TextureCoordinateStream { DataStream< Math::Vector2 >^ get( void ) { return vtc; } }
	property DataStream< VertexColor >^ ColorStream { DataStream< VertexColor >^ get( void ) { return vcl; } }

internal:
	VertexData( Model ^model );
	VertexData( Group ^group );

private:
	Model ^owner;

	int offset, count;

	DataStream< VertexPosition > ^vp;
	DataStream< VertexNormal > ^vn;
	DataStream< VertexTangentBasis > ^vt;
	DataStream< Math::Vector2 > ^vtc;
	DataStream< VertexColor > ^vcl;

	void InitStreams( int startIdx, int count );
};

};