I want to make my ship circle another ship, and the turnTowards method was not what I was looking for. How do I make it keep the same distance while circling and point to the ship?
kiarocks wrote ...
2012/3/27
How to make something circle?
Let's see. I think that's going to use some trigonometry. You're going to need a variable, an "int" or a "double", to keep track of the ship's distance along the circle. Call it "distanceAlongCirc". Then you have to update it by a certain number of degrees each frame. Than you need to update the position. It should come together like this:
Where radius is the size of the circle you want the ship to trace. You'll also need "sin()" and "cos()" methods that use degrees and not radians. I think they should be in Greenfoot's "Rotator" class.
I hope this helps, kiarocks!
1 2 3 4 5 6 7 8 | public void circleAroundPoint(int otherX, int otherY){ distanceAlongCirc += 25; int newX = cos(distanceAlongCirc) * radius; int newY = sin(distanceAlongCirc) * radius; setLocation(otherX + newX, getY() + newY);} |
Take a look at the Number class in this scenario: http://www.greenfoot.org/scenarios/3422
there is a method called 'LocationAroundPoint'.
Maybe this help you! (I'm although using it! x)
Thanks Morran! But what do I hand the method? My x and y, his x and y, or my x minus his x and my y minus his y?
New question: how do I make an arrow pint at something off screen, but without going of screen?
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