2

我有一个奇怪的问题，谷歌和 SO 搜索无法解决。这可能是非常简单的事情，但我已经折腾了几个小时，无法弄清楚。

我正在使用 Ncurses（使用 Ubuntu）在 C 中制作俄罗斯方块。

我的主函数调用一个 updatePiece() 函数，传入一个指向跟踪活动片段状态的结构的指针，以及键盘输入缓冲区。

结构：

struct piece {                                                                  
    struct coords pos;                                                          
    char currentMap[4][MAPSIZEX][MAPSIZEY];                                     
    int type;                                                                   
    int rotation;                                                               
    int leftColumn;                                                             
    int rightColumn;                                                            
    int bottomRow;                                                              
};

更新片功能：

void updatePiece(struct piece* piece, int input) {                              
    switch(input) {                                                             
        case KEY_UP:                                                            
            ++piece->rotation;                                                  
            if(piece->rotation == 4)                                            
                piece->rotation = 0;                                            
            getBoundary(piece);                                                 
            break;                                                              
        case KEY_RIGHT:                                                         
            if(piece->pos.x + piece->rightColumn != WELLSIZEX)                  
                ++piece->pos.x;                                                 
            break;                                                              
        case KEY_LEFT:                                                          
            if(piece->pos.x + piece->leftColumn != 0)                           
                --piece->pos.x;                                                 
            break;                                                              
        case 'p':                                                               
            ++piece->type;                                                      
            selectMap(piece);                                                   
            getBoundary(piece);                                                 
            break;                                                              
    }                                                                           

    if(piece->pos.y + piece->bottomRow >= WELLSIZEY)                            
        piece->pos.y = 0;                                                       
    ++piece->pos.y;                                                             
}

很酷，所以该函数可以移动棋子、旋转等。一旦当前棋子变为“死”等，我最终将使用 rand() 来选择一个新棋子，但现在我正在检测“p”正在输入和使用它来随意增加计数器。

然而，这件作品似乎只会旋转一次。使用 mvprintw() 告诉我 piece->type 的内容似乎没有改变。

所以我跳入 gdb 以了解发生了什么。一开始一切都很顺利；在标准输入检测到“p”，piece->type 确实增加了，然后调用 selectMap() 函数。这就是有趣的事情发生的地方。

void selectMap(struct piece* piece) {                                           
    switch(piece->type) {                                                       
        // T Piece                                                              
        case 0:                                                                 
            strcpy(piece->currentMap[0][0], "....");                            
            strcpy(piece->currentMap[0][1], ".X..");                            
            strcpy(piece->currentMap[0][2], "XXX.");                            
            strcpy(piece->currentMap[0][3], "....");                            
            strcpy(piece->currentMap[1][0], "....");                            
            strcpy(piece->currentMap[1][1], ".X..");                            
            strcpy(piece->currentMap[1][2], ".XX.");                            
            strcpy(piece->currentMap[1][3], ".X..");                            
            strcpy(piece->currentMap[2][0], "....");                            
            strcpy(piece->currentMap[2][1], "....");                            
            strcpy(piece->currentMap[2][2], "XXX.");                            
            strcpy(piece->currentMap[2][3], ".X..");                            
            strcpy(piece->currentMap[3][0], "....");                            
            strcpy(piece->currentMap[3][1], ".X..");                            
            strcpy(piece->currentMap[3][2], "XX..");                            
            strcpy(piece->currentMap[3][3], ".X..");                            
            return;                                                             
        // J Piece                                                               
        case 1:                                                                 
            strcpy(piece->currentMap[0][0], "....");                            
            strcpy(piece->currentMap[0][1], ".X..");                            
            strcpy(piece->currentMap[0][2], ".X..");                            
            strcpy(piece->currentMap[0][3], "XX..");                            
            strcpy(piece->currentMap[1][0], "....");                            
            strcpy(piece->currentMap[1][1], "X...");                            
            strcpy(piece->currentMap[1][2], "XXX.");                            
            strcpy(piece->currentMap[1][3], "....");                            
            strcpy(piece->currentMap[2][0], "....");                            
            strcpy(piece->currentMap[2][1], ".XX.");                            
            strcpy(piece->currentMap[2][2], ".X..");                            
            strcpy(piece->currentMap[2][3], ".X..");                            
            strcpy(piece->currentMap[3][0], "....");                            
            strcpy(piece->currentMap[3][1], "....");                            
            strcpy(piece->currentMap[3][2], "XXX.");                            
            strcpy(piece->currentMap[3][3], "..X.");                            
            return;   

           <REST OF FUNCTION OMITTED>
    }
}

该函数更改 currentPiece 字符数组以匹配当前片段类型。一切都复制得很好，但只要函数退出，piece->type 就会设置为 0。

我不知道为什么。Piece 是通过引用传递的，所以它不应该是范围问题。使用开关或一堆 if/else 无效。使用 break 或 return 无效。

这可能是一件非常简单和愚蠢的事情，但作为一个自学成才的程序员，这让我很难过。

任何帮助表示赞赏。整个代码如下（欢迎批评！）：

#include <ncurses.h>
#include <stdlib.h>
#include <string.h>

#define WELLSIZEX 10
#define WELLSIZEY 20
#define MAPSIZEX  4
#define MAPSIZEY  4
#define DELAY     100000

struct coords {
    int x;
    int y;
};

struct piece {
    struct coords pos;
    char currentMap[4][MAPSIZEX][MAPSIZEY];
    int type;
    int rotation;
    int leftColumn;
    int rightColumn;
    int bottomRow;
};


void selectMap(struct piece* piece) {
    switch(piece->type) {
        // T Piece
        case 0:
            strcpy(piece->currentMap[0][0], "....");
            strcpy(piece->currentMap[0][1], ".X..");
            strcpy(piece->currentMap[0][2], "XXX.");
            strcpy(piece->currentMap[0][3], "....");
            strcpy(piece->currentMap[1][0], "....");
            strcpy(piece->currentMap[1][1], ".X..");
            strcpy(piece->currentMap[1][2], ".XX.");
            strcpy(piece->currentMap[1][3], ".X..");
            strcpy(piece->currentMap[2][0], "....");
            strcpy(piece->currentMap[2][1], "....");
            strcpy(piece->currentMap[2][2], "XXX.");
            strcpy(piece->currentMap[2][3], ".X..");
            strcpy(piece->currentMap[3][0], "....");
            strcpy(piece->currentMap[3][1], ".X..");
            strcpy(piece->currentMap[3][2], "XX..");
            strcpy(piece->currentMap[3][3], ".X..");
            return;
        // J Piece
        case 1:
            strcpy(piece->currentMap[0][0], "....");
            strcpy(piece->currentMap[0][1], ".X..");
            strcpy(piece->currentMap[0][2], ".X..");
            strcpy(piece->currentMap[0][3], "XX..");
            strcpy(piece->currentMap[1][0], "....");
            strcpy(piece->currentMap[1][1], "X...");
            strcpy(piece->currentMap[1][2], "XXX.");
            strcpy(piece->currentMap[1][3], "....");
            strcpy(piece->currentMap[2][0], "....");
            strcpy(piece->currentMap[2][1], ".XX.");
            strcpy(piece->currentMap[2][2], ".X..");
            strcpy(piece->currentMap[2][3], ".X..");
            strcpy(piece->currentMap[3][0], "....");
            strcpy(piece->currentMap[3][1], "....");
            strcpy(piece->currentMap[3][2], "XXX.");
            strcpy(piece->currentMap[3][3], "..X.");
            return;
        // L Piece
        case 2:
            strcpy(piece->currentMap[0][0], "....");
            strcpy(piece->currentMap[0][1], ".X..");
            strcpy(piece->currentMap[0][2], ".X..");
            strcpy(piece->currentMap[0][3], ".XX.");
            strcpy(piece->currentMap[1][0], "....");
            strcpy(piece->currentMap[1][1], "....");
            strcpy(piece->currentMap[1][2], "XXX.");
            strcpy(piece->currentMap[1][3], "X...");
            strcpy(piece->currentMap[2][0], "....");
            strcpy(piece->currentMap[2][1], "XX..");
            strcpy(piece->currentMap[2][2], ".X..");
            strcpy(piece->currentMap[2][3], ".X..");
            strcpy(piece->currentMap[3][0], "....");
            strcpy(piece->currentMap[3][1], "..X.");
            strcpy(piece->currentMap[3][2], "XXX.");
            strcpy(piece->currentMap[3][3], "....");
            return;
        // O Piece  
        case 3:
            strcpy(piece->currentMap[0][0], "....");
            strcpy(piece->currentMap[0][1], ".XX.");
            strcpy(piece->currentMap[0][2], ".XX.");
            strcpy(piece->currentMap[0][3], "....");
            strcpy(piece->currentMap[1][0], "....");
            strcpy(piece->currentMap[1][1], ".XX.");
            strcpy(piece->currentMap[1][2], ".XX.");
            strcpy(piece->currentMap[1][3], "....");
            strcpy(piece->currentMap[2][0], "....");
            strcpy(piece->currentMap[2][1], ".XX.");
            strcpy(piece->currentMap[2][2], ".XX.");
            strcpy(piece->currentMap[2][3], "....");
            strcpy(piece->currentMap[3][0], "....");
            strcpy(piece->currentMap[3][1], ".XX.");
            strcpy(piece->currentMap[3][2], ".XX.");
            strcpy(piece->currentMap[3][3], "....");
            return;
        // I Piece
        case 4:
            strcpy(piece->currentMap[0][0], ".X..");
            strcpy(piece->currentMap[0][1], ".X..");
            strcpy(piece->currentMap[0][2], ".X..");
            strcpy(piece->currentMap[0][3], ".X..");
            strcpy(piece->currentMap[1][0], "....");
            strcpy(piece->currentMap[1][1], "....");
            strcpy(piece->currentMap[1][2], "XXXX");
            strcpy(piece->currentMap[1][3], "....");
            strcpy(piece->currentMap[2][0], ".X..");
            strcpy(piece->currentMap[2][1], ".X..");
            strcpy(piece->currentMap[2][2], ".X..");
            strcpy(piece->currentMap[2][3], ".X..");
            strcpy(piece->currentMap[3][0], "....");
            strcpy(piece->currentMap[3][1], "....");
            strcpy(piece->currentMap[3][2], "XXXX");
            strcpy(piece->currentMap[3][3], "....");
            return;
        // S Piece
        case 5:
            strcpy(piece->currentMap[0][0], "....");
            strcpy(piece->currentMap[0][1], ".XX.");
            strcpy(piece->currentMap[0][2], "XX..");
            strcpy(piece->currentMap[0][3], "....");
            strcpy(piece->currentMap[1][0], "....");
            strcpy(piece->currentMap[1][1], "X...");
            strcpy(piece->currentMap[1][2], "XX..");
            strcpy(piece->currentMap[1][3], ".X..");
            strcpy(piece->currentMap[2][0], "....");
            strcpy(piece->currentMap[2][1], ".XX.");
            strcpy(piece->currentMap[2][2], "XX..");
            strcpy(piece->currentMap[2][3], "....");
            strcpy(piece->currentMap[3][0], "....");
            strcpy(piece->currentMap[3][1], "X...");
            strcpy(piece->currentMap[3][2], "XX..");
            strcpy(piece->currentMap[3][3], ".X..");
            return;
        // Z Piece
        case 6:
            strcpy(piece->currentMap[0][0], "....");
            strcpy(piece->currentMap[0][1], "XX..");
            strcpy(piece->currentMap[0][2], ".XX.");
            strcpy(piece->currentMap[0][3], "....");
            strcpy(piece->currentMap[1][0], "....");
            strcpy(piece->currentMap[1][1], ".X..");
            strcpy(piece->currentMap[1][2], "XX..");
            strcpy(piece->currentMap[1][3], "X...");
            strcpy(piece->currentMap[2][0], "....");
            strcpy(piece->currentMap[2][1], "XX..");
            strcpy(piece->currentMap[2][2], ".XX.");
            strcpy(piece->currentMap[2][3], "....");
            strcpy(piece->currentMap[3][0], "....");
            strcpy(piece->currentMap[3][1], ".X..");
            strcpy(piece->currentMap[3][2], "XX..");
            strcpy(piece->currentMap[3][3], "X...");
            return;
        }
/*
        if(piece->type == 0) {
            strcpy(piece->currentMap[0][0], "....");
            strcpy(piece->currentMap[0][1], ".X..");
            strcpy(piece->currentMap[0][2], "XXX.");
            strcpy(piece->currentMap[0][3], "....");
            strcpy(piece->currentMap[1][0], "....");
            strcpy(piece->currentMap[1][1], ".X..");
            strcpy(piece->currentMap[1][2], ".XX.");
            strcpy(piece->currentMap[1][3], ".X..");
            strcpy(piece->currentMap[2][0], "....");
            strcpy(piece->currentMap[2][1], "....");
            strcpy(piece->currentMap[2][2], "XXX.");
            strcpy(piece->currentMap[2][3], ".X..");
            strcpy(piece->currentMap[3][0], "....");
            strcpy(piece->currentMap[3][1], ".X..");
            strcpy(piece->currentMap[3][2], "XX..");
            strcpy(piece->currentMap[3][3], ".X..");
        }
        if(piece->type == 1) {
            strcpy(piece->currentMap[0][0], "....");
            strcpy(piece->currentMap[0][1], ".X..");
            strcpy(piece->currentMap[0][2], ".X..");
            strcpy(piece->currentMap[0][3], "XX..");
            strcpy(piece->currentMap[1][0], "....");
            strcpy(piece->currentMap[1][1], "X...");
            strcpy(piece->currentMap[1][2], "XXX.");
            strcpy(piece->currentMap[1][3], "....");
            strcpy(piece->currentMap[2][0], "....");
            strcpy(piece->currentMap[2][1], ".XX.");
            strcpy(piece->currentMap[2][2], ".X..");
            strcpy(piece->currentMap[2][3], ".X..");
            strcpy(piece->currentMap[3][0], "....");
            strcpy(piece->currentMap[3][1], "....");
            strcpy(piece->currentMap[3][2], "XXX.");
            strcpy(piece->currentMap[3][3], "..X.");
        }
*/

}

void inits(struct piece* piece, char wellMap[WELLSIZEX][WELLSIZEY]) {
    piece->pos.x = piece->pos.y = 1;
    piece->rotation = 0;
    piece->type = 0;
    piece->leftColumn = 0;
    piece->rightColumn = 2;
    piece->bottomRow = 2;

    selectMap(piece);

    int x, y;
    for(y = 0; y < WELLSIZEY; ++y)
        for(x = 0; x < WELLSIZEX; ++x)
            wellMap[x][y] = '.';
}

void getBoundary(struct piece* piece) {
    // T Piece 
    if(piece->type == 0) {
        if(piece->rotation == 0) {
            piece->leftColumn = 0;
            piece->rightColumn = 2;
            piece->bottomRow = 2;
            return;
        }
        if(piece->rotation == 1) {
            piece->leftColumn = 1;
            piece->rightColumn = 2;
            piece->bottomRow = 3;
            return;
        }
        if(piece->rotation == 2) {
            piece->leftColumn = 0;
            piece->rightColumn = 2;
            piece->bottomRow = 3;
            return;
        }
        if(piece->rotation == 3) {
            piece->leftColumn = 0;
            piece->rightColumn = 1;
            piece->bottomRow = 3;
            return;
        }
    }
    // J Piece
    if(piece->type == 1) {
        if(piece->rotation == 0) {
            piece->leftColumn = 0;
            piece->rightColumn = 1;
            piece->bottomRow = 3;
            return;
        }
        if(piece->rotation == 1) {
            piece->leftColumn = 0;
            piece->rightColumn = 2;
            piece->bottomRow = 2;
            return;
        }
        if(piece->rotation == 2) {
            piece->leftColumn = 1;
            piece->rightColumn = 2;
            piece->bottomRow = 3;
            return;
        }
        if(piece->rotation == 3) {
            piece->leftColumn = 0;
            piece->rightColumn = 2;
            piece->bottomRow = 3;
            return;
        }
    }
    // L Piece
    if(piece->type == 2) { 
        if(piece->rotation == 0) {
            piece->leftColumn = 1;
            piece->rightColumn = 2;
            piece->bottomRow = 3;
            return;
        }
        if(piece->rotation == 1) {
            piece->leftColumn = 0;
            piece->rightColumn = 2;
            piece->bottomRow = 3;
            return;
        }
        if(piece->rotation == 2) {
            piece->leftColumn = 0;
            piece->rightColumn = 1;
            piece->bottomRow = 3;
            return;
        }
        if(piece->rotation == 3) {
            piece->leftColumn = 0;
            piece->rightColumn = 2;
            piece->bottomRow = 2;
            return;
        }
    }
    // O Piece
    if(piece->type == 3) {
        piece->leftColumn = 1;
        piece->rightColumn = 2;
        piece->bottomRow = 2;
        return;
    }
    // I Piece
    if(piece->type == 4) {
        if(piece->rotation == 0 || piece->rotation == 2) {
            piece->leftColumn = 1;
            piece->rightColumn = 1;
            piece->bottomRow = 3;
            return;
        }
        if(piece->rotation == 1 || piece->rotation == 3) {
            piece->leftColumn = 0;
            piece->rightColumn = 3;
            piece->bottomRow = 2;
            return;
        }
    }
    // S/Z Piece
    if(piece->type == 5 || piece->type == 6) {
        if(piece->rotation == 0 || piece->rotation == 2) {
            piece->leftColumn = 0;
            piece->rightColumn = 2;
            piece->bottomRow = 2;
            return;
        }
        if(piece->rotation == 1 || piece->rotation == 3) {
            piece->leftColumn = 0;
            piece->rightColumn = 1;
            piece->bottomRow = 3;
            return;
        }
    }
}

void updatePiece(struct piece* piece, int input) {
    switch(input) {
        case KEY_UP:
            ++piece->rotation;
            if(piece->rotation == 4)
                piece->rotation = 0;
            getBoundary(piece);
            break;
        case KEY_RIGHT:
            if(piece->pos.x + piece->rightColumn != WELLSIZEX)
                ++piece->pos.x;
            break;
        case KEY_LEFT:
            if(piece->pos.x + piece->leftColumn != 0)
                --piece->pos.x;
            break;
        case 'p':
            ++piece->type;
            selectMap(piece);
            getBoundary(piece);
            break;
    }

    if(piece->pos.y + piece->bottomRow >= WELLSIZEY)
        piece->pos.y = 0;
    ++piece->pos.y;
}

void drawWell(char wellMap[WELLSIZEX][WELLSIZEY]) {
    int y, x;
    for(y = 0; y < WELLSIZEY; ++y)
        for(x = 0; x < WELLSIZEX; ++x)
            mvaddch(y, x, wellMap[x][y]);

    for(y = 0; y < WELLSIZEY; ++y) {
        mvaddch(y,         0, '|');
        mvaddch(y, WELLSIZEX, '|');
    }

    for(x = 0; x <= WELLSIZEX; ++x) {
        mvaddch(        0, x, '-');
        mvaddch(WELLSIZEY, x, '-');
    }
}

void drawPiece(struct piece piece) {
    int x, y;
    for(y = 0; y < MAPSIZEY; ++y)
        for(x = 0; x < MAPSIZEX; ++x)
            mvaddch(piece.pos.y + y, piece.pos.x + x, piece.currentMap[piece.rotation][y][x]);
}

int main(void) {
    struct piece piece;
    char wellMap[WELLSIZEX][WELLSIZEY];

    initscr();
    cbreak();
    curs_set(FALSE);
    nodelay(stdscr, TRUE);
    keypad(stdscr, TRUE);

    inits(&piece, wellMap);
    while(1) {
        clear();
        /*
        if(isCollision) {
            blit();
            getNewPiece();
            piece.pos.y = 0;
            piece.pos.x = 3;
        }
        */
        updatePiece(&piece, getch());
        drawWell(wellMap);
        drawPiece(piece);
        mvprintw(2, 12, "l %d / dn %d / r %d / pce %d / rot %d",
                 piece.leftColumn, piece.bottomRow, piece.rightColumn,
                 piece.type, piece.rotation);
        refresh();
        usleep(DELAY);
    }
    return 0;
}
4

2 回答 2

5

您正在使用

char currentMap[4][MAPSIZEX][MAPSIZEY];

场地。

同时你在做

strcpy(piece->currentMap[0][0], "....");

和类似的东西。

由于零终止符，strcpy() 实际上写入了 5 个（不是 4 个）字节。

由于您在 currentMap 之后有“type”字段，因此您在那里得到零（“type”中的第一个字节被覆盖）。

将 memcpy() 用于 piece->currentMap[i][j] 或分配超过 4 个字节。

于 2012-05-30T12:20:01.553 回答
1

MAPSIZEY是4，但是您将 5 个字符复制到每个数组中（复制字符串".X.."并strcpy()复制您可以看到的四个字符加上空终止符）。

最后一个空终止符很可能会覆盖type值的第一个字节，并且如果您有一个小端机器，它将最低有效字节设置type为零。

于 2012-05-30T12:22:04.173 回答