SGScript - 2D Vector implementation

/*
    Vector2
*/

#define VEC2PTR mVec2* vec = (mVec2*) data->data
void* vec2_iface[];

int vec2_destruct( SGS_CTX, sgs_VarObj* data )
{
    VEC2PTR;
    delete vec;
    return SGS_SUCCESS;
}

int vec2_getprop( SGS_CTX, sgs_VarObj* data )
{
    VEC2PTR;
    const char* prop = sgs_ToString( C, -1 );
    if( gStrEqual( prop, "x" ) )        return sgs_PushReal( C, vec->x );
    if( gStrEqual( prop, "y" ) )        return sgs_PushReal( C, vec->y );
    if( gStrEqual( prop, "length" ) )   return sgs_PushReal( C, vec->Length() );
    if( gStrEqual( prop, "length_squared" ) )   return sgs_PushReal( C, vec->LengthSq() );
    if( gStrEqual( prop, "normalized" ) )       return sgs_PushObject( C, new mVec2( vec->Normalized() ), vec2_iface );
    if( gStrEqual( prop, "perp" ) )     return sgs_PushObject( C, new mVec2( vec->Perp() ), vec2_iface );
    if( gStrEqual( prop, "perp2" ) )    return sgs_PushObject( C, new mVec2( vec->Perp2() ), vec2_iface );
    return SGS_ENOTFND;
}

int vec2_setprop( SGS_CTX, sgs_VarObj* data )
{
    VEC2PTR;
    const char* prop = sgs_ToString( C, -1 );
    if( gStrEqual( prop, "x" ) )    vec->x = sgs_ToReal( C, -2 ); return SGS_SUCCESS;
    if( gStrEqual( prop, "y" ) )    vec->y = sgs_ToReal( C, -2 ); return SGS_SUCCESS;
    return SGS_ENOTFND;
}

int vec2_gettype( SGS_CTX, sgs_VarObj* data )
{
    sgs_PushString( C, "vec2" );
    return SGS_SUCCESS;
}

int vec2_tostring( SGS_CTX, sgs_VarObj* data )
{
    VEC2PTR;
    sgs_PushString( C, "vec2(" );
    sgs_PushReal( C, vec->x );
    sgs_PushString( C, ";" );
    sgs_PushReal( C, vec->y );
    sgs_PushString( C, ")" );
    sgs_StringMultiConcat( C, 5 );
    return SGS_SUCCESS;
}

void* vec2_iface[] =
{
    SOP_DESTRUCT, vec2_destruct,
    SOP_GETPROP, vec2_getprop,
    SOP_SETPROP, vec2_setprop,
    SOP_GETTYPE, vec2_gettype,
    SOP_TOSTRING, vec2_tostring,
    SOP_END,
};

int sgs_vec2( SGS_CTX )
{
    if( sgs_StackSize( C ) > 2 )
    {
        sgs_Printf( C, SGS_ERROR, -1, "Too many arguments for vec2" );
        return 0;
    }
    else if( sgs_StackSize( C ) > 1 )   sgs_PushObject( C, new mVec2( sgs_ToReal( C, 0 ), sgs_ToReal( C, 1 ) ), vec2_iface );
    else if( sgs_StackSize( C ) > 0 )   sgs_PushObject( C, new mVec2( sgs_ToReal( C, 0 ), sgs_ToReal( C, 0 ) ), vec2_iface );
    else                                sgs_PushObject( C, new mVec2( 0, 0 ), vec2_iface );
    return 1;
}

#define GETVEC2( idx ) (*(mVec2*)sgs_GetObjectData( C, idx ))
int sgs_vec2_dot( SGS_CTX )
{
    if( !sgs_CheckArgs( C, "vec2,vec2" ) )
        return 0;
    sgs_PushObject( C, new mVec2( GETVEC2( 0 ) * GETVEC2( 1 ) ), vec2_iface );
    return 1;
}

void* vec2_funcs[] =
{
    "vec2", sgs_vec2,
    "vec2_dot", sgs_vec2_dot,
    NULL,
};

int SGSRegister_Vec2( SGS_CTX )
{
    int err = SGSRegisterFunctions( C, vec2_funcs );
    if( err ) return err;

    return SGS_SUCCESS;
}