/*

Open Asset Import Library (assimp)

----------------------------------------------------------------------

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  copyright notice, this list of conditions and the

  following disclaimer.

* Redistributions in binary form must reproduce the above

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* Neither the name of the assimp team, nor the names of its

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*/

/** @file Md3FileData.h

 *

 *  @brief Defines 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 <stdint.h>

#include <assimp/types.h>

#include <assimp/mesh.h>

#include <assimp/anim.h>

#include <assimp/Compiler/pushpack1.h>

namespace Assimp {

namespace MD3 {

// to make it easier for us, we test the magic word against both "endiannesses"

#define AI_MD3_MAGIC_NUMBER_BE  AI_MAKE_MAGIC("IDP3")

#define AI_MD3_MAGIC_NUMBER_LE  AI_MAKE_MAGIC("3PDI")

// common limitations

#define AI_MD3_VERSION          15

#define AI_MD3_MAXQPATH         64

#define AI_MD3_MAXFRAME         16

#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

    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

{

    //! minimum bounds

    aiVector3D min;

    //! maximum bounds

    aiVector3D max;

    //! local origin for this frame

    aiVector3D origin;

    //! radius of bounding sphere

    ai_real radius;

    //! name of frame

    char name[ AI_MD3_MAXFRAME ];

} /* PACK_STRUCT */;

// -------------------------------------------------------------------------------

/**

 * @brief Data structure for the tag header

 */

struct Tag {

    //! name of the tag

    char NAME[ AI_MD3_MAXQPATH ];

    //! Local tag origin and orientation

    aiVector3D  origin;

    ai_real  orientation[3][3];

} /* PACK_STRUCT */;

// -------------------------------------------------------------------------------

/** @brief Data structure for the surface header

 */

struct Surface {

    //! magic number

    int32_t IDENT;

    //! original name of the surface

    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 defined in there

 */

struct Shader {

    //! filename of the shader

    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

    ai_real 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 <assimp/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, ai_real* p_afOut)

{

    ai_real lat = (ai_real)(( p_iNormal >> 8u ) & 0xff);

    ai_real lng = (ai_real)(( p_iNormal & 0xff ));

    const ai_real invVal( ai_real( 1.0 ) / ai_real( 128.0 ) );

    lat *= ai_real( 3.141926 ) * invVal;

    lng *= ai_real( 3.141926 ) * invVal;

    p_afOut[ 0 ] = std::cos(lat) * std::sin(lng);

    p_afOut[ 1 ] = std::sin(lat) * std::sin(lng);

    p_afOut[ 2 ] = std::cos(lng);

}

// -------------------------------------------------------------------------------

/** @brief Pack a Q3 normal into 16bit latitude/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 * ( std::atan2( p_vIn[1], p_vIn[0] ) ) * (255.0f / 360.0f ));

        a &= 0xff;

        b = int(57.2957795f * ( std::acos( p_vIn[2] ) ) * ( 255.0f / 360.0f ));

        b &= 0xff;

        ((unsigned char*)&p_iOut)[0] = (unsigned char) b;   // longitude

        ((unsigned char*)&p_iOut)[1] = (unsigned char) a;   // latitude

    }

}

} // Namespace MD3

} // Namespace Assimp

#endif // !! AI_MD3FILEHELPER_H_INC