文章目录

C版本1.1 显示静止的小球1.2 动态的小球(下落)1.3 动态的小球(斜着弹跳)1.4 动态的小球(Sleep慢速)1.5 动态的小球(使用循环减速)1.6 动态的小球(边界响铃)1.7 动态的小球(绘制边框)

C版本

1.1 显示静止的小球

使用printf函数在屏幕坐标(x, y)处显示一个静止的小球字符’O’，注意屏幕坐标系的原点在左上角，向右为X轴，向下为Y轴。

做法是先输出许多换行符，再输出一些空格，然后是小球字符。

#include <stdio.h> int main() { int x, y; x = 5, y = 10; for (int i = 0; i < y; i++) { printf("\n"); } for (int j = 0; j < x; j++) { printf(" "); } printf("o\n"); return 0; }

效果如图：

1.2 动态的小球(下落)

如果要实现小球的变动，就要每次输出一个小球后就清一下屏幕，然后改变小球的坐标。先从改变纵坐标y开始，定义一个速度变量velocity。

#include <stdio.h> #include <stdlib.h> int main() { int x, y, velocity = 1; x = 5, y = 0; while (1) { for (int i = 0; i < y; i++) { printf("\n"); } for (int j = 0; j < x; j++) { printf(" "); } printf("O\n"); system("cls"); y += velocity; } return 0; }

难以截图，不过发现了问题。小球会一直往下落。可以添加范围检查，当y大于或小于某范围值的时候，改变其方向。

#include <stdio.h> #include <stdlib.h> int main() { int x, y, velocity = 1; x = 10, y = 0; while (1) { for (int i = 0; i < y; i++) { printf("\n"); } for (int j = 0; j < x; j++) { printf(" "); } printf("O\n"); y += velocity; if (y >= 15 || y <= 0) velocity = -velocity; system("cls"); } return 0; }

1.3 动态的小球(斜着弹跳)

让小球还能够斜着弹跳，主要思路是同时改变x、y两个坐标的值。定义两个方向的速度velocity_x、velocity_y，初值为1，当碰到边界时改变两个方向的速度的正负号。

#include <stdio.h> #include <stdlib.h> int main() { int x, y, velocity_x, velocity_y; x = 5, y = 10; velocity_x = velocity_y = 1; int left, down, top, right; left = top = 0, down = 20, right = 40; while (1) { for (int i = 0; i < y; i++) { printf("\n"); } for (int j = 0; j < x; j++) { printf(" "); } printf("O\n"); y += velocity_y; x += velocity_x; if (y >= down || y <= top) velocity_y = -velocity_y; if (x >= right || x <= left) velocity_x = -velocity_x; system("cls"); } return 0; }

1.4 动态的小球(Sleep慢速)

发现上面的小球弹跳太快了，减慢一下速度。使用windows.h中的Sleep。 当需要用到Windows API进行开发的时候，比如说进行Windows窗口程序开发时，就会用到这个。如果是普通开发，或者有跨平台要求的时候，不要用这个头文件，因为它只面向Windows操作系统。

#include <stdio.h> #include <stdlib.h> #include <windows.h> int main() { int x, y, velocity_x, velocity_y; x = 5, y = 10; velocity_x = velocity_y = 1; int left, down, top, right; left = top = 0, down = 20, right = 40; while (1) { for (int i = 0; i < y; i++) { printf("\n"); } for (int j = 0; j < x; j++) { printf(" "); } printf("O\n"); y += velocity_y; x += velocity_x; if (y >= down || y <= top) velocity_y = -velocity_y; if (x >= right || x <= left) velocity_x = -velocity_x; Sleep(50); //50ms system("cls"); } return 0; }

1.5 动态的小球(使用循环减速)

用空循环就可以了，尝试了一下，发现5千万太慢，改成15000000，感觉还行。

#include <stdio.h> #include <stdlib.h> #include <windows.h> int main() { int x, y, velocity_x, velocity_y; x = 5, y = 10; velocity_x = velocity_y = 1; int left, down, top, right; left = top = 0, down = 20, right = 40; while (1) { for (int i = 0; i < y; i++) { printf("\n"); } for (int j = 0; j < x; j++) { printf(" "); } printf("o\n"); y += velocity_y; x += velocity_x; if (y >= down || y <= top) velocity_y = -velocity_y; if (x >= right || x <= left) velocity_x = -velocity_x; int k = 0; while (k++ < 18000000) ; system("cls"); } return 0; }

1.6 动态的小球(边界响铃)

可以使用转义字符“\a"来响铃。

#include <stdio.h> #include <stdlib.h> #include <windows.h> int main() { int x, y, velocity_x, velocity_y; x = 5, y = 10; velocity_x = velocity_y = 1; int left, down, top, right; left = top = 0, down = 20, right = 40; while (1) { for (int i = 0; i < y; i++) { printf("\n"); } for (int j = 0; j < x; j++) { printf(" "); } printf("O\n"); y += velocity_y; x += velocity_x; if (y >= down || y <= top) { velocity_y = -velocity_y; printf("\a"); } if (x >= right || x <= left) { velocity_x = -velocity_x; printf("\a"); } Sleep(50); //50ms system("cls"); } return 0; }

1.7 动态的小球(绘制边框)

绘制边框，也是输出字符作为边框。要和小球先输出上面的一部分，再输出下面的一部分边框。可以用‘H’作为边框。当然，还是存在一些问题，比如说屏幕不断闪烁…

#include <stdio.h> #include <stdlib.h> #include <windows.h> //小球坐标(x, y); 边框宽度和高度 void PrintAll(int x, int y, int width, int height) { for (int k = 0; k < width; k++) printf("█"); //障碍可以用H printf("\n"); for (int i = 1; i < height - 1; i++) { printf("█"); for (int j = 1; j < width - 1; j++) { if (i == y && j == x) printf("Ο"); //希腊字母Omicron else printf(" "); } printf("█\n"); } for (int k = 0; k < width; k++) printf("█"); printf("\n\n"); } int main() { int x, y, velocity_x, velocity_y; x = 1, y = 1; velocity_x = velocity_y = 1; int left, down, top, right; left = top = 0, down = 20, right = 40; while (1) { PrintAll(x, y, right, down); y += velocity_y; x += velocity_x; if (y + 2 == down || y - 1 == top) { //碰到障碍 velocity_y = -velocity_y; printf("\a"); } if (x + 2 == right || x - 1 == left) { //碰到障碍 velocity_x = -velocity_x; printf("\a"); } Sleep(100); system("cls"); } return 0; }