一起用C语言绘制一个动态的圣诞树吧

下面就是演示效果

一、实现步骤

我们利用ANSI Escape Sequences实现文字和背景颜色的绘制，之后使用系统命令定时刷新窗口并重新绘制圣诞树，以实现动态效果。相关函数如下所示：

• clrscr()：用于清理窗口；
• printRandLeaf()：随机化树叶的形状；
• triangle()：绘制圣诞树的每一层；
• printTree()：调用triangle()完成整个树冠的绘制；
• printLog()：完成整个树杆的绘制；

几个关键宏含义如下：

• RefRate：圣诞树的刷新频率，越小刷新越快；
• randomness：控制树叶中‘ * ’的密度，越大密度越高；
• WIDTH_FACTOR：控制圣诞树在窗口中的位置，最小值为2。值越大越往右边偏移；

二、编码实现

// 此C程序用于生成一棵圣诞树

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <string.h>

#define RefRate 40000
#define randomness 5 // 越高树叶越少
#define WIDTH_FACTOR 4

void clrscr()
{
    system("@cls||clear");
}

void printRandLeaf()
{
    char leaftypes[5] = { '.', '*', '+', 'o', 'O' };
    int temp = rand() % randomness;

    // Giving preference to *
    if (temp == 1){
        int other = rand() % 5;
        if(other == 3)
            printf("\x1b[38;5;160m%c \x1b[0m", leaftypes[other]);
        else if(other == 2)
            printf("\x1b[38;5;226m%c \x1b[0m", leaftypes[other]);
        else
            printf("%c ", leaftypes[other]);
    }else
        printf("\x1b[32m%c \x1b[0m", leaftypes[1]);
}

void triangle(int f, int n, int toth)
{
    int i, j, k = WIDTH_FACTOR * toth - 2;

    for (i = 0; i < f - 1; i++)
        k--;

    // number of rows
    for (i = f - 1; i < n; i++) {

        // space handler
        for (j = 0; j < k; j++)
            printf(" ");

        // decrementing k after each loop
        k = k - 1;

        // number of columns, printing stars
        for (j = 0; j <= i; j++)
            printRandLeaf();

        printf("\n");
    }
}

// Prints multiple triangles
void printTree(int h)
{
    int start = 1, stop = 0, diff = 3;
    while (stop < h + 1) {
        stop = start + diff;
        triangle(start, stop, h);
        diff++;
        start = stop - 2;
    }
}

// Prints bottom part.
void printLog(int n)
{
    int i, j, k = WIDTH_FACTOR * n - 4;

    for (i = 1; i <= 6; i++) {

        // space handler
        for (j = 0; j < k; j++)
            printf(" ");

        for (j = 1; j <= 6; j++)
            printf("\x1b[38;5;58m#\x1b[0m");

        printf("\n");
    }
}

// Driver code
int main()
{
    srand(time(NULL));
    int ht = 9;

    printf("\n*********MERRY CHRISTMAS*********\n\n");

    // refresh loop
    while (1) {
        clrscr();
        printf("\n\n\n");

        printTree(ht);
        printLog(ht);

        usleep(RefRate);
    }

    return 0;
}