Catapult with Box2D

ktc

I am looking for a simple catapult/canon example that uses Box2D. Is there any simple example I can learn from?

ar2rsawseen

hello @ktc
I think slingshot might be similar
http://appcodingeasy.com/Gideros-Mobile/Gideros--Box2d-Slingshot

ktc

@ar2rsawseen additional question. How can I make the cannons path visible. In other words cannon will leave its travel path in the screen.

ar2rsawseen

Well for example you have a Texture called dot (which represents one dot of path), then you can set up some kind of counter inside init function

self.cnt = 0

And then check inside onEnterFrame function if counter reached some point, for example value 10, take current body's position and place a dot there.

self.cnt = self.cnt + 1 if self.cnt == 10 then self.cnt = 0 local x, y = self.ball.body:getPosition() local dotImg = Bitmap.new(dot) dotImg:setAnchorPoint(0.5, 0.5) dotImg:setPosition(x, y) self:addChild(dotImg) end

Something like that