assimp/code/AssetLib/MD3/MD3FileData.h

/*
Open Asset Import Library (assimp)
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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 "endianesses"
#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 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 * ( 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