I would like object "Berry" to bounce off the edges of the screen. Where am I going wrong with this function?
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | ---->Bounce off walls xspeed, yspeed = math.random(-3,3), math.random(-3,3) function animate(event) berry.x = berry.x + (xspeed) berry.y = berry.y + (yspeed) if(berry.x < 1) then --left wall berry.x = berry.x + xspeed xSpeed = -xSpeed end if(berry.x > display.contentWidth-1) then --right wall berry.x = berry.x - xspeed xSpeed = -xSpeed end if(berry.y > display.contentHeight-1) then --floor berry.y = berry.y - yspeed ySpeed = -ySpeed end if(berry.y < 1) then --ceiling berry.y = berry.y + yspeed ySpeed = -ySpeed end end Runtime:addEventListener( "enterFrame", animate ); |
Try something like this, although you may want to adjust the left and top wall to line up with the starting speed - I just threw this together from your original code to give you an idea;
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | ---->Bounce off walls xspeed, yspeed = math.random(-3,3), math.random(-3,3) function animate(event) berry.x = berry.x + (xspeed) berry.y = berry.y + (yspeed) if(berry.x < 1) then --left wall berry.x = berry.x + xspeed*2 xspeed = 3 end if(berry.x > display.contentWidth-1) then --right wall berry.x = berry.x - xspeed*2 xspeed = -xspeed end if(berry.y > display.contentHeight-1) then --floor berry.y = berry.y - yspeed*2 yspeed = -yspeed end if(berry.y < 1) then --ceiling berry.y = berry.y + yspeed*2 yspeed = 3 end end Runtime:addEventListener( "enterFrame", animate ) |
views:1525 update：2011/12/30 9:10:41