The Enemy - Wave03: Bio Ships

(I called these ships 'Bio Ships' because that was the name of the graphic when I found it!) Yet another different enemy, yet another different attack pattern. I wanted these ones to go up and down as they moved across the screen, in a sort of sine wave (think Mexican Wave) motion but I'm absolutley crap at maths and didn't know where to begin! So I threw this open to the GMC and Tarik help me by saying that the y positioning of the ships could reverse when going above / below a certain number:


x+=1 // Movement to right.
if (y < 200)
{yChange = 1}
else
{if (y > 400) { yChange = -1}}
y += yChange


Although this didn't produce a smooth sine wave motion, it did the job of having the ships move up and down as they moved along. Coupled with the bullets aiming towards the player, you had to think fast to get through this wave!