easyX类平抛小球

easyX类平抛小球

1.只需要在加速下落小球的情况下增加一个水平速度分量即可

#include<graphics.h>
#include<conio.h>
#define WIDTH 800   //窗口宽度
#define HEIGHT 600   //窗口高度

int main()
{
    //设置小球坐标
    float ballX = 10;
    float ballY = 20;
    //设置水平以及竖直速度
    float vx = 30;
    float vy = 0.0;
    //设置水平加速度垂直加速度
    float g = 0.5;
    float a = 0.2;
    initgraph(WIDTH, HEIGHT);
    while (1)
    {
        vx = vx - a;
        vy = vy + g;
        //改变ballX ballY
        ballX = ballX + vx;
        ballY = ballY + vy;
        //设置反弹
        if (ballY >= HEIGHT - 10)   //下边界处理
        {
            vy = -0.95*vy;  
        }
        if (ballX >= WIDTH - 20)   //右边界处理
        {
            vx = -0.95*vx;
        }
        if (ballX <= 20)          //左边界处理
        {
            vx = -0.95 * vx;
        }
        if (ballY > HEIGHT - 10)
        {
            ballY = HEIGHT - 10;
            ballX = ballX-vx;
        }

        cleardevice();
        fillcircle(ballX, ballY, 10);
        Sleep(100);
    }

    _getch();
    closegraph();

    return 0;
}