Increase object Velocity+Spawn Rate based on timer or score.

Getting Started Newbie Questions
#1

I copied this object spawning code from the documentation to play with the numbers and see how it works so i could apply it to the game i am currently working on.

this almost mimics what i am building currently but i need to increase either the velocity or spawn rate based on a timer or score, i cant seem to figure out how to do so. 

local backGround = display.newImageRect("Images/BackGround1.png", display.contentWidth, display.contentHeight) backGround.x = display.contentCenterX backGround.y = display.contentCenterY local physics = require("physics") physics.start() physics.setGravity( 0, 0 ) -------------------------------------------------------------------------------- local spawnTimer local spawnedObjects = {} -- Seed the random number generator math.randomseed( os.time() ) local spawnParams = { xMin = 110, xMax = 250, yMin = -50, yMax = -50, spawnTime = 3000, spawnOnTimer = 12, spawnInitial = 0 } -- Spawn an item local function spawnItem( bounds ) -- Create an item local item = display.newCircle( 0, 0, 20 ) physics.addBody( item, "dynamic", {radius=20 , bounce = 0.5} ) item:setLinearVelocity( 0,100 ) -- Position item randomly within set bounds item.x = math.random( bounds.xMin, bounds.xMax ) item.y = math.random( bounds.yMin, bounds.yMax ) -- Add item to "spawnedObjects" table for tracking purposes spawnedObjects[#spawnedObjects+1] = item end local function spawnController( action, params ) -- Cancel timer on "start" or "stop", if it exists if ( spawnTimer and ( action == "start" or action == "stop" ) ) then timer.cancel( spawnTimer ) end -- Start spawning if ( action == "start" ) then -- Gather/set spawning bounds local spawnBounds = {} spawnBounds.xMin = spawnParams.xMin or 0 spawnBounds.xMax = spawnParams.xMax or display.contentWidth spawnBounds.yMin = spawnParams.yMin or 0 spawnBounds.yMax = spawnParams.yMax or display.contentHeight -- Gather/set other spawning params local spawnTime = spawnParams.spawnTime or 1000 local spawnOnTimer = spawnParams.spawnOnTimer or 50 local spawnInitial = spawnParams.spawnInitial or 0 -- If "spawnInitial" is greater than 0, spawn that many item(s) instantly if ( spawnInitial \> 0 ) then for n = 1,spawnInitial do spawnItem( spawnBounds ) end end -- Start repeating timer to spawn items if ( spawnOnTimer \> 0 ) then spawnTimer = timer.performWithDelay( spawnTime, function() spawnItem( spawnBounds ); end, spawnOnTimer ) end -- Pause spawning elseif ( action == "pause" ) then timer.pause( spawnTimer ) -- Resume spawning elseif ( action == "resume" ) then timer.resume( spawnTimer ) end end spawnController( "start", spawnParams )
#2

If you look at the timer “spawnTimer” you will see that it is using the variable  “spawnTime” which in turn is defined by “spawnParams.spawnTime”.  So you can adjust the time in the table “spawnParams”

[lua]

local spawnParams = {

    xMin = 110,

    xMax = 250,

    yMin = -50,

    yMax = -50,

    spawnTime = 3000, – this is the variable that controls the time for the timer

    spawnOnTimer = 12,

    spawnInitial = 0

}

– When you are ready to adjust the timer - cancel the timer, change the spawn time and then restart the timer using spawnController

timer.cancel( spawnTimer ) – cancel timer / stop spawning

spawnParams.spawnTime = 2500 – change the spawn time to whatever you want

spawnController( “start”, spawnParams ) – restart the spawning

[/lua]

#3

*note - spawnTimer is predeclared outside of the spawnController function so when I say look at “spawnTimer” I mean when it is assigned as a timer in the spawnController function.

#4

i was able to figure out how to make it work but now, i guess im attempting or want to try and do it a bit different 

here is the code from my project 

in the function createObjects i set the velocity of all of the objects  that are spawning to fallRate which is equal to 30

i used the fallRate variable in place of the second parameter for setLinearVelocity in attmept to modify the variable with a function based off the score changing… say for every 10 score the velocity should increase by 10 

i put 2000 in its place just to attempt to get the process working. 

i attempted to get this to work by creating 

local function increaseFallRate() if (score == 3) then fallRate = 2000 end end

but this did not work im not sure where to go from here, i thought maybe i could change the way i spawn the objects but then it became more complicated for what im trying to accomplish.

is there a way to do this with what i have or do i have to rewrite the way my spawning works?  

----------------------------------------------------------------------------------------- -- -- main.lua -- ----------------------------------------------------------------------------------------- local physics = require("physics") physics.start() physics.setGravity( 0, 0 ) physics.setDrawMode( "hybrid" ) math.randomseed(os.time()) local lives = 3 local score = 0 local died = false local ObjectsTable = {} local newObject local gameLoopTimer local livesText local ScoreText local fallRate = 30 local delayRate = 3000 local backGroup = display.newGroup() local mainGroup = display.newGroup() local uiGroup = display.newGroup() local backGround = display.newImageRect(backGroup, "Images/BackGround1.png", display.contentWidth, display.contentHeight) backGround.x = display.contentCenterX backGround.y = display.contentCenterY livesText = display.newText( uiGroup, "Lives: ".. lives, 55,30, native.systemFont, 20 ) ScoreText = display.newText(uiGroup, "Score: ".. score,56, 55, native.systemFont, 20) local function updateText() livesText.text = "Lives: " .. lives ScoreText.text = "Score: " .. score end local function createObjects() newObject = display.newImageRect(mainGroup,"Objects/Object" .. math.random(18) .. ".png", 69.2 , 60.8) table.insert( ObjectsTable, newObject ) physics.addBody( newObject, "dynamic", {radius=0 , bounce = 0.5} ) -- changing radius adjusts hit box, hitbox does not mean touchbox newObject.myName = "Object" -------------------------------------------------------------------------------- local function dragObject ( event ) newObject = event.target local phase = event.phase if ( "began" == phase ) then display.currentStage:setFocus( newObject, event.id ) newObject.isFocus = true newObject.touchOffsetX = event.x - newObject.x newObject.touchOffsetY = event.y - newObject.y elseif ( newObject.isFocus ) then if ( "moved" == phase) then newObject.x = event.x - newObject.touchOffsetX newObject.y = event.y - newObject.touchOffsetY elseif ( "ended" == phase or "cancelled" == phase ) then display.currentStage:setFocus(newObject, nil ) newObject.isFocus = false end end return true end newObject:addEventListener( "touch", dragObject) ------------------------------------------------------------------------------ local whereFrom --from top newObject.x = math.random(100, 240) -- keeps Objects within middle of screen newObject.y = -60 newObject:setLinearVelocity( 0, fallRate) -- param 2 changes falling speed end local function decreaseDelay() if (score == 3) then fallRate = 2000 end end local function gameLoop() createObjects() for i = #ObjectsTable, 1, -1 do local thisObject = ObjectsTable[i] if ( thisObject.x \< -100 or thisObject.x \> display.contentWidth + 100 or thisObject.y \< -100 or thisObject.y \> display.contentHeight + 100) then display.remove( thisObject ) table.remove( ObjectsTable, i ) end end end gameLoopTimer = timer.performWithDelay( delayRate, gameLoop, 0 ) -- param one sets delay between new Object spawn
#5

I have resolved this by creating a function that states 

local function bonusLife() if score == score + 5 then lives = lives + 1 livesText.text = "Lives: ".. lives end end

using this same method i was able to increase the fallRate variable i declared earlier. there may be a cleaner way to do this but for now i just create 2 more functions to check the score again to see if it increased another 5 to continue increasing the fallRate.