帆布像大轮子一样旋转矩形

Question

So I have a level and want the x,y of a rect to move around like a big wheel. I am going to use it as a platform to reach the end point. So every frame it moves 1 or 2 pixels. Just wondering how to go about this?

I can do a diamond shape easily enough by for 50 loops the x would be ++; and the y would be ++; then after 50 the x would be --; and the y would be ++; and so on.

How is a circle done?

Answer 1

Not quite sure what you are trying to do, but if I understand the question right, you should store the current angle of the rectangle, theta , and then update x and y as r*sin(theta)+offset_x and r*cos(theta)+offset_y where the offsets are the position of the centre of rotation. Then each frame increase theta by some small amount.