创建游戏内核（3）

本篇是的创建游戏内核（2）续篇，并且以游戏程序流、状态处理机、进程管理器、数据包系统的实现中介绍的进程管理器的实现为基础。

栈上的每个函数在每帧都要被调用，除了这点小的不同之处，PROCESS_MANAGER和STATE_MANAGER非常相似。

以下是该类的定义：

//==========================================================================
// Defines for process manager.
//==========================================================================
class PROCESS_MANAGER
{
private:
    struct PROCESS
    {
        FUNC_PTR func;
        PROCESS* next;

        PROCESS()
        {
            func = NULL;
            next = NULL;
        }

        ~PROCESS()
        {
            delete next;
            next = NULL;
        }
    };

protected:
    PROCESS* _process_parent;

public:
    PROCESS_MANAGER();
    ~PROCESS_MANAGER();

    void Push(FUNC_PTR func, void* data_ptr = NULL);
    BOOL Pop(void* data_ptr = NULL);
    void Pop_All(void* data_ptr = NULL);
    void Process(void* data_ptr = NULL);
};

接着是它的实现:

//-----------------------------------------------------------------------------
// Constructor.
//-----------------------------------------------------------------------------
PROCESS_MANAGER::PROCESS_MANAGER()
{
    _process_parent = NULL;
}

//-----------------------------------------------------------------------------
// Destructor, pop all functions.
//-----------------------------------------------------------------------------
PROCESS_MANAGER::~PROCESS_MANAGER()
{
    // pop each process
    while(Pop() == TRUE)
        ;
}

//-----------------------------------------------------------------------------
// Push a function on to the stack
//-----------------------------------------------------------------------------
void PROCESS_MANAGER::Push(FUNC_PTR func, void* data_ptr)
{
    // don't push a NULL value
    if(func != NULL)
    {
        // allocate a new process and push it on stack
        PROCESS* process_ptr = new PROCESS();

        process_ptr->func = func;
        process_ptr->next = _process_parent;

        _process_parent = process_ptr;

        // call process with init purpose
        process_ptr->func(data_ptr, INIT_PURPOSE);
    }
}

//-----------------------------------------------------------------------------
// Pop top process from stack
//-----------------------------------------------------------------------------
BOOL PROCESS_MANAGER::Pop(void* data_ptr)
{
    PROCESS*  process_ptr;

    // remove the head of stack (if any)
    if((process_ptr = _process_parent) != NULL)
    {
        // first call with shutdown purpose
        _process_parent->func(data_ptr, SHUTDOWN_PURPOSE);

        _process_parent   = process_ptr->next;
        process_ptr->next = NULL;

        delete process_ptr;
    }

    // return TRUE if more processes exist, FALSE otherwise
    return (_process_parent != NULL);
}

//-----------------------------------------------------------------------------
// Pop all process.
//-----------------------------------------------------------------------------
void PROCESS_MANAGER::Pop_All(void* data_ptr)
{
    while(Pop(data_ptr) == TRUE)
        ;
}

//-----------------------------------------------------------------------------
// Process all functions
//-----------------------------------------------------------------------------
void PROCESS_MANAGER::Process(void* data_ptr)
{
    PROCESS* process_ptr = _process_parent;

    while(process_ptr != NULL)
    {
        process_ptr->func(data_ptr, FRAME_PURPOSE);
        process_ptr = process_ptr->next;
    }
}

下面给出测试代码：

点击下载源码和工程

/*****************************************************************************
PURPOSE:
    Test for class PROCESS_MANAGER.
*****************************************************************************/

#include "Core_System.h"

#pragma warning(disable : 4996)

class APP : public APPLICATION
{
private:
    PROCESS_MANAGER _process_manager;

    static void _Function1(void*, long);
    static void _Function2(void*, long);

public:
    BOOL Init()
    {
        _process_manager.Push(_Function1, this);
        _process_manager.Push(_Function2, this);

        return TRUE;
    }

    BOOL Frame()
    {
        _process_manager.Process(this);

        _process_manager.Pop_All(this);

        return TRUE;
    }
};

void APP::_Function1(void* data_ptr, long purpose)
{
    APP* app_inst = (APP*) data_ptr;

    if(app_inst != NULL)
    {
        if(purpose == INIT_PURPOSE)
            MessageBox(app_inst->Get_Hwnd(), "Process1 - init", "Message", MB_OK);
        else if(purpose == FRAME_PURPOSE)
            MessageBox(app_inst->Get_Hwnd(), "Process1 - frame", "Message", MB_OK);
        else if(purpose == SHUTDOWN_PURPOSE)
            MessageBox(app_inst->Get_Hwnd(), "Process1 - shutdown", "Message", MB_OK);
    }
}

void APP::_Function2(void* data_ptr, long purpose)
{
    APP* app_inst = (APP*) data_ptr;

    if(app_inst != NULL)
    {
        if(purpose == INIT_PURPOSE)
            MessageBox(app_inst->Get_Hwnd(), "Process2 - init", "Message", MB_OK);
        else if(purpose == FRAME_PURPOSE)
            MessageBox(app_inst->Get_Hwnd(), "Process2 - frame", "Message", MB_OK);
        else if(purpose == SHUTDOWN_PURPOSE)
            MessageBox(app_inst->Get_Hwnd(), "Process2 - shutdown", "Message", MB_OK);
    }
}

int PASCAL WinMain(HINSTANCE inst, HINSTANCE, LPSTR cmd_line, int cmd_show)
{
    APP app;

    return app.Run();
}

运行截图：

posted on 2007-08-26 00:29 lovedday 阅读(434) 评论(0) 编辑收藏引用

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