coin pattern generation using tables

Getting Started Newbie Questions
#1

I tried making coin patterns using lua tables and a general method, then added all of them in a group. They seem to be working fine but I’m facing difficulty in spawning them.  These are the two ways I tried …

(This one is not actually my code … )

local coinPatterns={ line={{x=0,y=0},{x=25,y=0},{x=50,y=0}} } -- Create Individual Coin local function createCoin(x,y) local coin=display.newImageRect("images/coin.png",20,20) coin.anchorX,coin.anchorY=0,0 coin.y=y coin.x=x coin.id='coin' physics.addBody(coin,'static',{isSensor=true,radius=10}) return coin end -- Create a coin group local function createCoinGroup() local coinGroup=display.newGroup() for key,value in pairs(coinPatterns.line) do local coin=createCoin(value.x,value.y) coinGroup:insert(coin) end coinGroup.x=screenW coinGroup.y=50 transition.to(coinGroup,{time=2000,x=0-coinGroup.width,onComplete=function() coinGroup:removeSelf() coinGroup=nil end}) foregroundGroup:insert(coinGroup) end createCoinGroup()

after this hardly worked I tried a simple approach :

local function coinLine5() local coin1=display.newImage(COINGROUP,"coin.png") coin1.x=100 coin1.y=100 physics.addBody(coin1,"static",{density = 1, bounce = 0.1, friction = 2, radius = 20}) coin1.myName="coin1" local coin2=display.newImage(COINGROUP,"coin.png") coin2.x=120 coin2.y=100 physics.addBody(coin2,"static",{density = 1, bounce = 0.1, friction = 2, radius = 20}) coin2.myName="coin2" local coin3=display.newImage(COINGROUP,"coin.png") coin3.x=140 coin3.y=100 physics.addBody(coin3,"static",{density = 1, bounce = 0.1, friction = 2, radius = 20}) coin3.myName="coin3" local coin4=display.newImage(COINGROUP,"coin.png") coin4.x=160 coin4.y=100 physics.addBody(coin4,"static",{density = 1, bounce = 0.1, friction = 2, radius = 20}) coin4.myName="coin4" local coin5=display.newImage(COINGROUP,"coin.png") coin5.x=180 coin5.y=100 physics.addBody(coin5,"static",{density = 1, bounce = 0.1, friction = 2, radius = 20}) coin5.myName="coin5" COINGROUP.x=600 end coinLine5() local function moveCoins(self,event) if self.x \< -500 then Runtime:removeEventListener("enterFrame", COINGROUP) COINGROUP:removeSelf() COINGROUP=nil else self.x = self.x - objectSpeed end end COINGROUP.enterFrame=moveCoins

Same issue in both the methods … unable to spawn the coin … plz help … !!!

#2

DRY

try this

local coinPatterns = { &nbsp;&nbsp; &nbsp;["Line"] = { {x = 0, y = 0},{x = 30, y = 0},{x = 60, y = 0}&nbsp; }, &nbsp;&nbsp; &nbsp;["Diagonal"] = { {x = 0, y = -50},{x = 30, y = 0 },{x = 60, y = 50}} } local function SpawnCoins (params) &nbsp;&nbsp; &nbsp;local tmp = {} &nbsp;&nbsp; &nbsp;tmp.rect = display.newRect(params.group, params.x, params.y, 10, 10 ) &nbsp;&nbsp; &nbsp;function tmp:destroy() &nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;display.remove(self.rect) &nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;self.rect = nil &nbsp;&nbsp; &nbsp;end &nbsp;&nbsp; &nbsp;function tmp:move(speed) &nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;self.rect:translate( -speed, 0 ) &nbsp;&nbsp; &nbsp;end &nbsp;&nbsp; &nbsp;return tmp end local CoinGroup = display.newGroup() local CurCoins = {} for k,v in pairs( coinPatterns["Diagonal"] ) do &nbsp;&nbsp; &nbsp;CurCoins[k] = SpawnCoins({x = v.x,y = v.y, group = CoinGroup}) end CoinGroup.x = 320 CoinGroup.y = 240 Runtime:addEventListener( "enterFrame", function () &nbsp;&nbsp; &nbsp;for i = 1,#CurCoins do &nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;CurCoins[i]:move(2) &nbsp;&nbsp; &nbsp;end end )
#3

Thank you so much !!! Nice article on DRY …

The thing is I was able to create Coin groups using tables … the difficulty is in spawning them ( the collision function ) … In your code how do I refer to a specific coin ( rectangle ) in the collision function … I added the coins to physics body … how should i call the destroy function ?

#4 
-- destroy specific coins by using -- 1 is the coins index, so the first one CurCoins[1]:destroy()

btw if you are adding physics bodies make sure you do it within the SpawnCoin function

#5

The problem is the event listener for colloison function is tmp:addEventListener(“collision”, onCollision)

so the function only checks for one specific coin and not the whole lot … and using CurCoins[i]:addEventListener(“collision”, onCollision)

is not permitted . So do I have to write seperate case for each element (coin) of the pattern ?

P.S. : I’m confused with the usage of collision function for the whole group i.e. complete CurCoins {}

#6

nope use a table listener

here is a simple touch example make sure you place code similar to this within the SpawnCoin function

local function onTouch(self,event) -- the 'self' parameter contains a reference to the object -- it only applies to that peticular instance! &nbsp;&nbsp;&nbsp; print(self) end tmp.rect.touch = onTouch tmp.rect:addEventListener( "touch", tmp.rect )
#7

if I’m not wrong touch is used when user touches the screen rite ?  I’m trying to spawn the coin when my jet passes through it or collides with it !!!

#8

that was just an example, adapt the code to suit your needs

#9

DRY

try this

local coinPatterns = { &nbsp;&nbsp; &nbsp;["Line"] = { {x = 0, y = 0},{x = 30, y = 0},{x = 60, y = 0}&nbsp; }, &nbsp;&nbsp; &nbsp;["Diagonal"] = { {x = 0, y = -50},{x = 30, y = 0 },{x = 60, y = 50}} } local function SpawnCoins (params) &nbsp;&nbsp; &nbsp;local tmp = {} &nbsp;&nbsp; &nbsp;tmp.rect = display.newRect(params.group, params.x, params.y, 10, 10 ) &nbsp;&nbsp; &nbsp;function tmp:destroy() &nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;display.remove(self.rect) &nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;self.rect = nil &nbsp;&nbsp; &nbsp;end &nbsp;&nbsp; &nbsp;function tmp:move(speed) &nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;self.rect:translate( -speed, 0 ) &nbsp;&nbsp; &nbsp;end &nbsp;&nbsp; &nbsp;return tmp end local CoinGroup = display.newGroup() local CurCoins = {} for k,v in pairs( coinPatterns["Diagonal"] ) do &nbsp;&nbsp; &nbsp;CurCoins[k] = SpawnCoins({x = v.x,y = v.y, group = CoinGroup}) end CoinGroup.x = 320 CoinGroup.y = 240 Runtime:addEventListener( "enterFrame", function () &nbsp;&nbsp; &nbsp;for i = 1,#CurCoins do &nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;CurCoins[i]:move(2) &nbsp;&nbsp; &nbsp;end end )
#10

Thank you so much !!! Nice article on DRY …

The thing is I was able to create Coin groups using tables … the difficulty is in spawning them ( the collision function ) … In your code how do I refer to a specific coin ( rectangle ) in the collision function … I added the coins to physics body … how should i call the destroy function ?

#11 
-- destroy specific coins by using -- 1 is the coins index, so the first one CurCoins[1]:destroy()

btw if you are adding physics bodies make sure you do it within the SpawnCoin function

#12

The problem is the event listener for colloison function is tmp:addEventListener(“collision”, onCollision)

so the function only checks for one specific coin and not the whole lot … and using CurCoins[i]:addEventListener(“collision”, onCollision)

is not permitted . So do I have to write seperate case for each element (coin) of the pattern ?

P.S. : I’m confused with the usage of collision function for the whole group i.e. complete CurCoins {}

#13

nope use a table listener

here is a simple touch example make sure you place code similar to this within the SpawnCoin function

local function onTouch(self,event) -- the 'self' parameter contains a reference to the object -- it only applies to that peticular instance! &nbsp;&nbsp;&nbsp; print(self) end tmp.rect.touch = onTouch tmp.rect:addEventListener( "touch", tmp.rect )
#14

if I’m not wrong touch is used when user touches the screen rite ?  I’m trying to spawn the coin when my jet passes through it or collides with it !!!

#15

that was just an example, adapt the code to suit your needs