C语言——贪吃蛇（第二阶段小蛇的移动

#include<stdio.h>
#include<stdlib.h>
#include<windows.h>

#define High 20         //游戏画面尺寸
#define Width 30

//全局变量t
int canvas[High][Width] = {0};
int moveDirection;

void gotoxy(int x, int y)
{
    HANDLE handle = GetStdHandle(STD_OUTPUT_HANDLE);
    COORD pos;
    pos.X = x;
    pos.Y = y;
    SetConsoleCursorPosition(handle,pos);
}

void moveSneakeByDirection()
{
    int i,j;

    for(i = 1; i < High-1; i++)
        for(j = 1; j < Width-1; j++)
            if(canvas[i][j] > 0)
                canvas[i][j]++;

    int oldTail_i, oldTail_j, oldHead_i, oldHead_j;
    int max = 0;

    for(i = 1; i < High-1; i++)
        for(j = 1; j < Width-1; j++)
            if(canvas[i][j] > 0)
    {
        if(max < canvas[i][j])
        {
            max = canvas[i][j];
            oldTail_i = i;
            oldTail_j = j;
        }

        if(canvas[i][j] == 2)
        {
            oldHead_i = i;
            oldHead_j = j;
        }
    }

    canvas[oldTail_i][oldTail_j] = 0;

    if(moveDirection == 1)
        canvas[oldHead_i-1][oldHead_j] = 1;
    if(moveDirection == 2)
        canvas[oldHead_i+1][oldHead_j] = 1;
    if(moveDirection == 3)
        canvas[oldHead_i][oldHead_j-1] = 1;
    if(moveDirection == 4)
        canvas[oldHead_i][oldHead_j+1] = 1;
}

void startup()          //数据初始化
{
    int i,j;

    //初始化边框
    for(i = 0; i < High; i++)
    {
        canvas[i][0] = -1;
        canvas[i][Width-1] = -1;
    }

    for(j = 0; j < Width; j++)
    {
        canvas[0][j] = -1;
        canvas[High-1][j] = -1;
    }

    //初始化蛇头的位置
    canvas[High/2][Width/2] = 1;

    //初始化蛇身，画布中的元素值分别为2，3，4，5等
    for(i = 1; i <= 4; i++)
        canvas[High/2][Width/2-i] = i+1;

    moveDirection = 4;
}

void show()         //显示画面
{
    gotoxy(0,0);
    int i,j;

    for(i = 0; i < High; i++)
    {
        for(j = 0; j < Width; j++)
        {
        if(canvas[i][j] == 0)
            printf(" ");
        else if(canvas[i][j] == -1)
            printf("#");
        else if(canvas[i][j] == 1)
            printf("@");            //蛇头
        else if(canvas[i][j] > 1)
            printf("*");            //蛇身
        }

        printf("\n");
    }
}

void updateWithoutInput()       //与用户输入无关的更新
{

}

void updateWithInput()          //与用户输入有关的更新
{

}

int main()
{
    startup();
    while(1)
    {
        show();
        updateWithoutInput();
        updateWithInput();
    }

    return 0;
}