程式碼如下:
程式碼如下:
跳跳球
//盒子
var box_x=0;
var box_y=0;
var box_width=300;
var box_height=300;
//注意:定位球採用球的中心
var ball_x=10;
var ball_y=10 ;
var ball_radius=10;
var ball_vx=5;
var ball_vy=3;
var box_bound_left=box_x ball_radius;
var _bound_rightbox_xpound =box_y ball_radius;
var box_bound_bottom=box_y box_height-ball_radius;
//球
//上下文
var ctx;
function init()
var ctx;
function init()
.getElementById('canvas').getContext('2d');
ctx.lineWidth=ball_radius;
ctx.fillStyle="rgb(200,0,50)";
move_ball(); 🎜>setInterval(move_ball,100);//注意
}
function move_ball()
{
ctx.clearRect(box_x,box_y,box_width,box_height);
ctx.beginPath();
ctx.arc(ball_x,ball_y,ball_radius,0,Math.PI*2,true);
ctx.fill();
ctx.StrokeRect(box_xxx ,box_y,box_width,box_height);
}
函數move_and_check()
{
var cur_ball_x=ball_x ball_vx;
var cur_ball_y_ball_yball_x ball_vx;
var cur_ball_y_vmbox_-ball_i_vv;
{
ball_vx=-ball_vx;
cur_ball_x=box_bound_left;
}
if(cur_ball_x>box_bound_right)
{ }
if(cur_ball_y{
ball_vy=-ball_vy;
cur_ball_y=box_bound_top;
}
cur_ball_y=box_bound_top;
}
if(cur帶_y>if(cur帶_y>if(cur帶)
ball_vy=-ball_vy;
cur_ball_y=box_bound_bottom;
}
ball_x=cur_ball_x;
ball_y=cur_ball_y;
}
腳本
>
身體>