将分屏多人游戏添加到c ++游戏中

Question

我使用libnds在c ++中编写NDS代码，但这个问题不是NDS特有的。我目前有一个基于文本的游戏，其中顶部屏幕只显示一个徽标，你在底部屏幕上播放。

所以我想添加一种单DS多人游戏，其中一个玩家在顶部屏幕上播放，另一个玩家在底部播放。我在使用两个屏幕设置文本引擎时没有问题，我只需要找到一种在多人游戏中高效编码的方法。下面我写了一个摘要或简化版本。

注意：consoleClear（）清除屏幕，游戏停止的唯一位置是暂停功能。

//Headers

void display(int x,int y,const char* output))
{
    printf("\x1b[%d;%dH%s", y, x,output);
}

void pause(KEYPAD_BITS key) //KEYPAD_BITS is an ENUM for a key on the NDS
{
    scanKeys();
    while (keysHeld() & key)
    {
        scanKeys();
        swiWaitForVBlank();
    }
    while (!(keysHeld() & key))
    {
        scanKeys();
        swiWaitForVBlank();
    }
    return;
}

void pause() //Only used to simplify coding
{
    pause(KEY_A);
    return;
}

int main(void)
{
    //Initializations/Setup
    while (1)
    {
        if (rand()%2==1) //Say Hello
        {
            if (rand()%3!=1) //To Friend (greater chance of friend than enemy)
            {
                display(6,7,"Hello Friend!");
                display(6,8,"Good greetings to you.");
                pause();
                consoleClear(); //Clears text
                display(6,7,"Would you like to come in?");
                pause();
                //Normally more complex complex code (such as interactions with inventories) would go here
            }
            else //To enemy
            {
                display(6,7,"Hello enemy!");
                display(6,8,"I hate you!");
                pause();
                consoleClear();
                display(6,7,"Leave my house right now!!!");
                pause();
            }
        }
        else //Say goodbye
        {
            if (rand()%4==1) //To Friend (lesser chance of friend than enemy)
            {
                display(6,7,"Goodbye Friend!");
                display(6,8,"Good wishes to you.");
                pause();
                consoleClear();
                display(6,7,"I'll see you tomorrow.");
                pause();
                consoleClear();
                display(6,7,"Wait, I forgot to give you this present.");
                pause();
            }
            else //To enemy
            {
                display(6,7,"Goodbye enemy!");
                display(6,8,"I hate you!");
                pause();
                consoleClear();
                display(6,7,"Never come back!!");
                pause();
                consoleClear();
                display(6,7,"Good riddance!"); //I think I spelt that wrong...
                pause();
            }
        }
    }
}

我知道搞砸了，这可能被认为是一个坏习惯，但我想不出更好的方法。我的多人游戏集成版本：

//Headers and same functions

int game(int location)
{
    switch (location)
    {
    case 1: goto one; break;
    case 2: goto two; break;
    case 3: goto three; break;
    case 4: goto four; break;
    case 5: goto five; break;
    case 6: goto six; break;
    case 7: goto seven; break;
    case 8: goto eight; break;
    case 9: goto nine; break;
    case 10: goto ten; break;
    default: break;
    }

    if (rand()%2==1) //Say Hello
    {
        if (rand()%3!=1) //To Friend (greater chance of friend than enemy)
        {
            display(6,7,"Hello Friend!");
            display(6,8,"Good greetings to you.");
            return 1;
one:;
            consoleClear(); //Clears text
            display(6,7,"Would you like to come in?");
            return 2;
two:;
            //Normally more complex complex code (such as interactions with inventories) would go here
        }
        else //To enemy
        {
            display(6,7,"Hello enemy!");
            display(6,8,"I hate you!");
            return 3;
three:;
            consoleClear();
            display(6,7,"Leave my house right now!!!");
            return 4;
four:;
        }
    }
    else //Say goodbye
    {
        if (rand()%4==1) //To Friend (lesser chance of friend than enemy)
        {
            display(6,7,"Goodbye Friend!");
            display(6,8,"Good wishes to you.");
            return 5;
five:;
            consoleClear();
            display(6,7,"I'll see you tomorrow.");
            return 6;
six:;
            consoleClear();
            display(6,7,"Wait, I forgot to give you this present.");
            return 7;
seven:;
        }
        else //To enemy
        {
            display(6,7,"Goodbye enemy!");
            display(6,8,"I hate you!");
            return 8;
eight:;
            consoleClear();
            display(6,7,"Never come back!!");
            return 9;
nine:;
            consoleClear();
            display(6,7,"Good riddance!"); //I think I spelt that wrong...
            return 10;
ten:;
        }
        return -1;
    }
}
int main(void)
{
    //Initializations/Setup
    int location1 = -1, location2 = -1;
    location1 = game(location1);
    location2 = game(location2);
    while (1)
    {
        scanKeys(); //Whenever checking key state this must be called
        if (keysDown() & KEY_A) //A key is used to continue for player1
            location1 = game(location1);
        if (keysDown() & KEY_DOWN) //Down key is used to continue for player2
            location2 = game(location2);
    }
}

除了这种方法是一种不好的做法，在实际的源代码中，我有数百个我需要添加的东西，这太费时了。

感谢任何帮助。如果有人有任何疑问或回答，请询问/回复。

编辑：虽然不喜欢这样做，但如果有人有办法，我愿意从头开始重写游戏。

Answer 1

对每个案例使用if-else条件语句是一个首先考虑的简单解决方案。

例如：

int game(int i){
  if(i == 1){
    //first case code here.
  }
  else if(i == 2){
    //second case code here.
  }
  //....
  return 0;
}

每种情况下的代码甚至可以放在将根据每个条件调用的其他函数中。 这可能足以满足您的需求。

更灵活的解决方案（但更复杂）是 调度表 。 我们的想法是为每个所需的功能提供单独的功能，并将它们的指针放在一个数组中。然后，您可以通过使用这些函数指针索引表来调用它们。如果您要执行一系列执行（函数调用）并且您希望轻松完成它，或者希望根据您的输入获得不同的结果，而不更改您的程序，这将非常有用。

下面有一个例子。 如果用printf替换std :: cout，用 stdio 库替换 iostream ，也可以在C中使用此代码。

#include <iostream>

using namespace std;

// Arrays start from 0.
// This is used for code
// readability reasons.
#define CASE(X) X-1 

typedef void (*chooseCase)();

// Functions to execute each case.
// Here, I am just printing
// different strings.
void case1(){
    cout<< "case1" << endl;
}

void case2(){
    cout<< "case2" << endl;
}

void case3(){
    cout<< "case3" << endl;
}

void case4(){
    cout<< "case4" << endl;
}

//Put all the cases in an array.
chooseCase cases[] = {
    case1, case2, case3, case4
};

int main()
{
    //You can call each scenario
    //by hand easily this way:
    cases[CASE(1)]();
    cout << endl;

    //Idea: You can even set in another
    // array a sequence of function executions desired.
    int casesSequence[] = {
        CASE(1), CASE(2), CASE(3), CASE(4),CASE(3),CASE(2),CASE(1)
    };
    //Execute the functions in the sequence set.
    for(int i = 0; i < (sizeof(casesSequence)/sizeof(int)); ++i){
        cases[casesSequence[i]]();
    }

    return 0;
}

这将在输出处打印：

case1

case1
case2
case3
case4
case3
case2
case1