Scrolling and physics

Comments

• zaniar Member

  October 2012

  How did you know that the physics bodies are not 'attached'? Are you using DebugDraw?

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• cvieira Member

  October 2012

  @Tom2012, can you exemplify what's really going on? It would be helpful if you include code sample here so people can analyze....

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• OZApps Guru

  October 2012

  @Tom, are you scrolling the ground by altering the x/y coordinates? and are you also scrolling the physics bodies in the same way or are you expecting them to update in the enter frame?

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• Tom2012 Guru

  October 2012

  Thanks guys
  
  I found the solution was to add the physics world to a separate layer to that of the scene:

  local physicsLayer = Sprite.new() -- create new sprite instance physicsLayer.world = b2.World.new(0, 10, true) -- add the physics on this layer self:addChild(physicsLayer); -- add sprite to this scene

  I can then scroll the layer with my scroll class:

  Scrolling = Core.class(Sprite);   function Scrolling:init(ground,bg1,bg2,hector,physicsLayer)   -- Variables   self.groundLeftEdge = 0; self.groundRightEdge = 0;   self.ground = ground; self.bg1 = bg1; self.bg2 = bg2; self.hector = hector; self.physicsLayer = physicsLayer;   self:addEventListener(Event.ENTER_FRAME, self.onEnterFrame, self)   end       -- Enterframe loop   function Scrolling:onEnterFrame()     if(self.hector.moving == "left") then   if(self.hector:getX() < 160 + (self.hector:getWidth()/2)) then self.groundLeftEdge = self.ground:getX() - (self.ground:getWidth()/2)   if(self.groundLeftEdge < 0) then self.bg2:setX(self.bg2:getX() + self.hector.speed * .45) self.bg1:setX(self.bg1:getX() + self.hector.speed * .3) self.ground:setX(self.ground:getX() + self.hector.speed) self.physicsLayer:setX(self.physicsLayer:getX() + self.hector.speed) -- move the phsics world too else if(self.hector:getX() > 37) then self.hector:setX(self.hector:getX()-self.hector.speed) -- no scrolling, hector walk else self.hector.moving = "stopped"; end end else self.hector:setX(self.hector:getX() - self.hector.speed) end   end   if(self.hector.moving == "right") then   if(self.hector:getX() > (160 - (self.hector:getWidth() / 2))) then self.groundRightEdge = self.ground:getX() + (self.ground:getWidth()/2)   if(self.groundRightEdge > application:getContentWidth()) then self.bg2:setX(self.bg2:getX() - self.hector.speed * .45) self.bg1:setX(self.bg1:getX() - self.hector.speed * .3) self.ground:setX(self.ground:getX() - self.hector.speed) self.physicsLayer:setX(self.physicsLayer:getX() - self.hector.speed) -- move the phsics world too else if(self.hector:getX() < 283) then self.hector:setX(self.hector:getX() + self.hector.speed) else self.hector.moving = "stopped"; end end else self.hector:setX(self.hector:getX() + self.hector.speed) end   end         end

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