Lua (8), idlcpplua

Lua (8), idlcpplua

Previous Article Lua in this idlcpp tutorial on C ++ hybrid programming (7)

Article 1 idlcpp tutorial in C ++ hybrid programming (I)

Similar to the previous project, LuaTutorial6 also includes four files: LuaTutorial6.cpp, Tutorial6.cpp, Tutorial6. I, and tutorial6.lua. The content of LuaTutorial6.cpp is basically the same as that of LuaTutorial5.cpp.

First, let's take a look at Tutorial6. I:

 

namespace tutorial{    template<typename N>    struct Vector3    {        Vector3();        Vector3(const Vector3 ref v);        Vector3(N a, N b, N c);        Vector3(const N ptr p);        N getLength();        N length get;        N lengthSquare get;        static Vector3 s_zero;        meta:        N x;        N y;        N z;        N v[$3];        $*        union        {            struct            {                N x,y,z;            };            N v[3];        };        *$    };    template class Vector3<float>;    template class Vector3<double>;    typedef Vector3<float> Vector3f;    typedef Vector3<double> Vector3d;    $*    template<typename N>    Vector3<N> Vector3<N>::s_zero(0, 0, 0);    template<typename N>    inline Vector3<N>::Vector3()    {    }    template<typename N>    inline Vector3<N>::Vector3(const Vector3<N>& v) : x(v.x), y(v.y), z(v.z)    {}    template<typename N>    inline Vector3<N>::Vector3(N a, N b, N c) : x(a), y(b), z(c)    {}    template<typename N>    inline Vector3<N>::Vector3(const N* p) : x(p[0]), y(p[1]), z(p[2])    {}    template<typename N>    inline N Vector3<N>::getLength()    {        return N(sqrt(x * x + y * y + z * z));    }    template<typename N>    inline N Vector3<N>::get_length()    {        return N(sqrt(x * x + y * y + z * z));    }    template<typename N>    inline N Vector3<N>::get_lengthSquare()    {        return (x * x + y * y + z * z);    }    *$}

 

Template <typename N>

Struct Vector3

This is a template class. The C ++ template is complex and powerful, and the compiler is really hard to write. Therefore, the advanced features of most C ++ templates are not supported in idlcpp. After all, idlcpp is only responsible for providing interfaces to the script language, and some simple template functions are enough, the template-related syntax is consistent with that of C ++.

Static Vector3 s_zero;

This row declares a static member variable. Idlcpp supports static member variables, static member functions, and static attributes (actually static member functions ).

Meta:

N x;

N y;

N z;

N v [$3];

$ *

Union

{

Struct

{

N x, y, z;

};

N v [3];

};

* $

Idlcpp does not provide union. Fortunately, you can use meta and $ ** $ to provide their respective content in the generated metadata description code and the C ++ header file.

The following two lines of code

Template class Vector3 <float>;

Template class Vector3 <double>;

It is consistent with the template class declaration in C ++.

In idlcpp, such declaration statements generate metadata information of the corresponding type. These two statements are optional for C ++, but for idlcpp, to make the script see the two template class instance types, these two lines of code must be written.

The following two lines of code

Typedef Vector3 <float> Vector3f;

Typedef Vector3 <double> Vector3d;

The Type alias is declared for the template class instance type. Because these two types of names are: tutorial: Vector3 <float> and: tutorial: Vector3 <double>, it is inconvenient to use them in scripts, with the type alias, you can use: tutorial: Vector3f and: tutorial: Vector3d.

The implementation code of member functions will be described later.

The content of the compiled Tutorial6.h is as follows:

 

//DO NOT EDIT THIS FILE, it is generated by idlcpp//http://www.idlcpp.org#pragma once#include "./Tutorial6.h"namespace tutorial{    template <typename  N>    struct Vector3    {    public:        Vector3();        Vector3(const Vector3& v);        Vector3(N a,N b,N c);        Vector3(const N* p);        N getLength();        N get_length();        N get_lengthSquare();        static Vector3 s_zero;    public:        static Vector3* New();        static Vector3* New(N a,N b,N c);        static Vector3* New(const N* p);        static Vector3* NewArray(unsigned int count);        static Vector3* Clone(const Vector3& v);        union        {            struct            {                N x,y,z;            };            N v[3];        };            };    typedef Vector3<float> Vector3f;    typedef Vector3<double> Vector3d;    template<typename N>    Vector3<N> Vector3<N>::s_zero(0, 0, 0);    template<typename N>    inline Vector3<N>::Vector3()    {    }    template<typename N>    inline Vector3<N>::Vector3(const Vector3<N>& v) : x(v.x), y(v.y), z(v.z)    {}    template<typename N>    inline Vector3<N>::Vector3(N a, N b, N c) : x(a), y(b), z(c)    {}    template<typename N>    inline Vector3<N>::Vector3(const N* p) : x(p[0]), y(p[1]), z(p[2])    {}    template<typename N>    inline N Vector3<N>::getLength()    {        return N(sqrt(x * x + y * y + z * z));    }    template<typename N>    inline N Vector3<N>::get_length()    {        return N(sqrt(x * x + y * y + z * z));    }    template<typename N>    inline N Vector3<N>::get_lengthSquare()    {        return (x * x + y * y + z * z);    }    }

 

Idlcpp generates the corresponding function declaration get_length and get_lengthSquare for the read-only attribute length and lengthSquare. Idlcpp generates the corresponding static functions New, NewArray, and Clone according to the constructor declaration.

For other content, C ++ and idl are basically the same.

Then Tutorial6.cpp

 

#include "Tutorial6.h"#include "Tutorial6.mh"#include "Tutorial6.ic"#include "Tutorial6.mc"

Because the template class code is written in the header file, Tutorial6.cpp only needs to contain the corresponding four files.

Finally, let's take a look at Tutorial6.lua.

v1 = paf.tutorial.Vector3f(1,1,2);v1.z = 1;print(v1.length._);v2 = paf.tutorial.Vector3d(2,2,1);v2.v[2] = 2;print(v2:getLength()._);

 

Compile and execute the command. The result is as follows: