/*
Open Asset Import Library (ASSIMP)
----------------------------------------------------------------------

Copyright (c) 2006-2008, ASSIMP Development Team
All rights reserved.

Redistribution and use of this software in source and binary forms, 
with or without modification, are permitted provided that the 
following conditions are met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
  materials provided with the distribution.

* Neither the name of the ASSIMP team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the ASSIMP Development Team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
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----------------------------------------------------------------------
*/

/** @file Defines the helper data structures for importing MD3 files.
      http://linux.ucla.edu/~phaethon/q3/formats/md3format.html
*/
#ifndef AI_MD3FILEHELPER_H_INC
#define AI_MD3FILEHELPER_H_INC

#include <string>
#include <vector>
#include <sstream>

#include "../include/aiTypes.h"
#include "../include/aiMesh.h"
#include "../include/aiAnim.h"

#include "./../include/Compiler/pushpack1.h"

namespace Assimp	{
namespace MD3	{

// to make it easier for ourselfes, we test the magic word against both "endianesses"
#define MD3_MAKE(string) ((uint32_t)((string[0] << 24) + (string[1] << 16) + (string[2] << 8) + string[3]))

#define AI_MD3_MAGIC_NUMBER_BE	MD3_MAKE("IDP3")
#define AI_MD3_MAGIC_NUMBER_LE	MD3_MAKE("3PDI")

// common limitations
#define AI_MD3_VERSION			15
#define AI_MD3_MAXQPATH			64
#define AI_MD3_MAX_FRAMES		1024
#define AI_MD3_MAX_TAGS			16
#define AI_MD3_MAX_SURFACES		32
#define AI_MD3_MAX_SHADERS		256	
#define AI_MD3_MAX_VERTS		4096	
#define AI_MD3_MAX_TRIANGLES	8192	

// master scale factor for all vertices in a MD3 model
#define AI_MD3_XYZ_SCALE		(1.0f/64.0f)

// ---------------------------------------------------------------------------
/** \brief Data structure for the MD3 main header
 */
// ---------------------------------------------------------------------------
struct Header
{
	//! magic number
	uint32_t IDENT;

	//! file format version
	uint32_t VERSION;

	//! original name in .pak archive
	unsigned char NAME[ AI_MD3_MAXQPATH ];

	//! unknown
	int32_t FLAGS;

	//! number of frames in the file
	uint32_t NUM_FRAMES;

	//! number of tags in the file
	uint32_t NUM_TAGS;

	//! number of surfaces in the file
	uint32_t NUM_SURFACES;

	//! number of skins in the file
	uint32_t NUM_SKINS;

	//! offset of the first frame
	uint32_t OFS_FRAMES;

	//! offset of the first tag
	uint32_t OFS_TAGS;

	//! offset of the first surface
	uint32_t OFS_SURFACES;

	//! end of file
	uint32_t OFS_EOF;
} PACK_STRUCT;


// ---------------------------------------------------------------------------
/** \brief Data structure for the frame header
 */
// ---------------------------------------------------------------------------
struct Frame
{
	// no need to define this, we won't need
} PACK_STRUCT;


// ---------------------------------------------------------------------------
/** \brief Data structure for the tag header
 */
// ---------------------------------------------------------------------------
struct Tag
{
	// no need to define this, we won't need
} PACK_STRUCT;


// ---------------------------------------------------------------------------
/** \brief Data structure for the surface header
 */
// ---------------------------------------------------------------------------
struct Surface
{
	//! magic number
	int32_t IDENT;

	//! original name of the surface
	unsigned char NAME[ AI_MD3_MAXQPATH ];

	//! unknown
	int32_t FLAGS;

	//! number of frames in the surface
	uint32_t NUM_FRAMES;

	//! number of shaders in the surface
	uint32_t NUM_SHADER;

	//! number of vertices in the surface
	uint32_t NUM_VERTICES;

	//! number of triangles in the surface
	uint32_t NUM_TRIANGLES;


	//! offset to the triangle data 
	uint32_t OFS_TRIANGLES;

	//! offset to the shader data
	uint32_t OFS_SHADERS;

	//! offset to the texture coordinate data
	uint32_t OFS_ST;

	//! offset to the vertex/normal data
	uint32_t OFS_XYZNORMAL;

	//! offset to the end of the Surface object
	int32_t OFS_END;
} PACK_STRUCT;

// ---------------------------------------------------------------------------
/** \brief Data structure for a shader
 */
// ---------------------------------------------------------------------------
struct Shader
{
	//! filename of the shader
	unsigned char NAME[ AI_MD3_MAXQPATH ];

	//! index of the shader
	uint32_t SHADER_INDEX;
} PACK_STRUCT;


// ---------------------------------------------------------------------------
/** \brief Data structure for a triangle
 */
// ---------------------------------------------------------------------------
struct Triangle
{
	//! triangle indices
	uint32_t INDEXES[3];
} PACK_STRUCT;


// ---------------------------------------------------------------------------
/** \brief Data structure for an UV coord
 */
// ---------------------------------------------------------------------------
struct TexCoord
{
	//! UV coordinates
	float U,V;
} PACK_STRUCT;


// ---------------------------------------------------------------------------
/** \brief Data structure for a vertex
 */
// ---------------------------------------------------------------------------
struct Vertex
{
	//! X/Y/Z coordinates
	int16_t X,Y,Z;

	//! encoded normal vector
	uint16_t  NORMAL;
} PACK_STRUCT;

#include "./../include/Compiler/poppack1.h"

// ---------------------------------------------------------------------------
/**	\brief Unpack a Q3 16 bit vector to its full float3 representation
 *
 *	\param p_iNormal Input normal vector in latitude/longitude form
 *	\param p_afOut Pointer to an array of three floats to receive the result
 *
 *	\note This has been taken from q3 source (misc_model.c)
 */
// ---------------------------------------------------------------------------
inline void LatLngNormalToVec3(uint16_t p_iNormal, float* p_afOut)
{
	float lat = (float)(( p_iNormal >> 8u ) & 0xff);
	float lng = (float)(( p_iNormal & 0xff ));
	lat *= 3.141926f/128.0f;
	lng *= 3.141926f/128.0f;

	p_afOut[0] = cosf(lat) * sinf(lng);
	p_afOut[1] = sinf(lat) * sinf(lng);
	p_afOut[2] = cosf(lng);
	return;
}


// ---------------------------------------------------------------------------
/**	\brief Pack a Q3 normal into 16bit latitute/longitude representation
 *	\param p_vIn Input vector
 *	\param p_iOut Output normal
 *
 *	\note This has been taken from q3 source (mathlib.c)
 */
// ---------------------------------------------------------------------------
inline void Vec3NormalToLatLng( const aiVector3D& p_vIn, uint16_t& p_iOut ) 
{
	// check for singularities
	if ( 0.0f == p_vIn[0] && 0.0f == p_vIn[1] ) 
	{
		if ( p_vIn[2] > 0.0f ) 
		{
			((unsigned char*)&p_iOut)[0] = 0;
			((unsigned char*)&p_iOut)[1] = 0;		// lat = 0, long = 0
		} 
		else 
		{
			((unsigned char*)&p_iOut)[0] = 128;
			((unsigned char*)&p_iOut)[1] = 0;		// lat = 0, long = 128
		}
	} 
	else 
	{
		int	a, b;

		a = int(57.2957795f * ( atan2f( p_vIn[1], p_vIn[0] ) ) * (255.0f / 360.0f ));
		a &= 0xff;

		b = int(57.2957795f * ( acosf( p_vIn[2] ) ) * ( 255.0f / 360.0f ));
		b &= 0xff;

		((unsigned char*)&p_iOut)[0] = b;	// longitude
		((unsigned char*)&p_iOut)[1] = a;	// lattitude
	}
}

}
}

#endif // !! AI_MD3FILEHELPER_H_INC

