Lifebar : How to increase lifebar oncollision with other object? - lua

Question

I've build my own lifebar (progressive bar) as follow :
function scene:enterScene(event)
storyboard.removeScene("start")
screenGroup = self.view
lifeBar = {}
lives = 141 -- is the global width of my full lifebar
maxLives = 141
for i = 1, maxLives do
lifeBar[i] = display.newImage("lifebar.png") --lifebar.png image width is : 1px
lifeBar[i].anchorX=0
lifeBar[i].anchorY=0.6
lifeBar[i].x = fuel_title.x +114+13.5+(lifeBar[i].contentWidth * (i - 1))
lifeBar[i].y = 37 -- start at 10,10
lifeBar[i].isVisible=true
screenGroup:insert(lifeBar[i])
end
end
So, thanks to you, i've know a function which increase the lives (livesValue.text shows the increased lives), whatever, the lifebar{} table seems to have some problems because i cannot see a difference in the lifebar image. My question is : Is there something wrong with my table lifeBar ?
if (event.other.myName == "fuel") then
if lives > maxLives then
lives = maxLives
elseif lives < #lifeBar then
lives = lives + 1
lifeBar[lives].isVisible=true
end
livesValue.text = string.format("%d", lives)
local other = event.other
timer.performWithDelay(1, function() other:removeSelf() end)
end
Runtime:addEventListener("touch", FuelManage)

Answer 1

Try this:
function onCollision( self, event )
if event.phase == "began" then
if event.other.myName == "fuel" then
-- increase life bar, if slots left:
if lives < #lifeBar then
lives = lives + 1
lifeBar[lives].isVisible=true
end
-- schedule the fuel object we collided with for removal:
local other = event.other -- don't want to use event as upvalue
timer.performWithDelay(1, function() other:removeSelf() end)
end
end
end
Note that you are not allowed to remove collision objects in the collision handler, you have to do this with delay, as explained on the Corona Collision docs page. So I have done that. Also you should only add lives if you there is space in the lifeBar (similarly you should fix your code to remove life only if there is more than 0 lives).