Hi! In my platform game the player has to draw a line to keep the main character inside the screen, instead of let it fall down.
Anyway now I would like to scroll the background when the game character bounce on the line drawed by players.
Here’s the code I’m using:
The first one is my actual scrolling background which move continuely
local bgSpeed = 3,5; -- SPEED TO MOVE BACKGROUND AT
local bg1 = display.newImage("backGround01.png", 0, 0); -- place bg1 at the origin
local bg2 = display.newImage("backGround02.png", 0, bg1.y + (bg1.height \* 1.5));
local bg3 = display.newImage("backGround03.png", 0, bg1.y + (bg1.height \* 1.5));
local bg4 = display.newImage("backGround04.png", 0, bg1.y + (bg1.height \* 1.5));
local bg5 = display.newImage("backGround05.png", 0, bg1.y + (bg1.height \* 1.5));
local bg6 = display.newImage("backGround06.png", 0, bg1.y + (bg1.height \* 1.5));
local bg7 = display.newImage("backGround07.png", 0, bg1.y + (bg1.height \* 1.5));
local bg8 = display.newImage("backGround08.png", 0, bg1.y + (bg1.height \* 1.5));
local bg9 = display.newImage("backGround09.png", 0, bg1.y + (bg1.height \* 1.5));
local bg10 = display.newImage("backGround10.png", 0, bg1.y + (bg1.height \* 1.5));
local bg11 = display.newImage("backGround11.png", 0, bg1.y + (bg1.height \* 1.5));
local bg12 = display.newImage("backGround12.png", 0, bg1.y + (bg1.height \* 1.5));
local bg13 = display.newImage("backGround13.png", 0, bg1.y + (bg1.height \* 1.5));
local bg14 = display.newImage("backGround14.png", 0, bg1.y + (bg1.height \* 1.5));
local bg15 = display.newImage("backGround15.png", 0, bg1.y + (bg1.height \* 1.5));
local bg16 = display.newImage("backGround16.png", 0, bg1.y + (bg1.height \* 1.5));
local bg17 = display.newImage("backGround16.png", 0, bg1.y + (bg1.height \* 1.5));
local moveBG = function(e)
bg1:translate(0, bgSpeed);
bg2:translate(0, bgSpeed);
bg3:translate(0, bgSpeed);
bg4:translate(0, bgSpeed);
bg5:translate(0, bgSpeed);
bg6:translate(0, bgSpeed);
bg7:translate(0, bgSpeed);
bg8:translate(0, bgSpeed);
bg9:translate(0, bgSpeed);
bg10:translate(0, bgSpeed);
bg11:translate(0, bgSpeed);
bg12:translate(0, bgSpeed);
bg13:translate(0, bgSpeed);
bg14:translate(0, bgSpeed);
bg15:translate(0, bgSpeed);
bg16:translate(0, bgSpeed);
bg17:translate(0, bgSpeed);
if ((bg1.y - bg1.height / 2) \> display.contentHeight) then
bg1.y = bg2.y - bg2.height;
elseif((bg2.y - bg2.height / 2) \> display.contentHeight) then
bg2.y = bg1.y - bg1.height;
elseif((bg3.y - bg3.height / 2) \> display.contentHeight) then
bg3.y = bg2.y - bg1.height;
elseif((bg4.y - bg4.height / 2) \> display.contentHeight) then
bg4.y = bg3.y - bg2.height;
elseif((bg5.y - bg5.height / 2) \> display.contentHeight) then
bg5.y = bg4.y - bg3.height;
elseif((bg6.y - bg6.height / 2) \> display.contentHeight) then
bg6.y = bg5.y - bg4.height;
elseif((bg7.y - bg7.height / 2) \> display.contentHeight) then
bg7.y = bg6.y - bg5.height;
elseif((bg8.y - bg8.height / 2) \> display.contentHeight) then
bg8.y = bg7.y - bg6.height;
elseif((bg9.y - bg9.height / 2) \> display.contentHeight) then
bg9.y = bg8.y - bg7.height;
elseif((bg10.y - bg10.height / 2) \> display.contentHeight) then
bg10.y = bg9.y - bg8.height;
elseif((bg11.y - bg11.height / 2) \> display.contentHeight) then
bg11.y = bg10.y - bg9.height;
elseif((bg12.y - bg12.height / 2) \> display.contentHeight) then
bg12.y = bg11.y - bg10.height;
elseif((bg13.y - bg13.height / 2) \> display.contentHeight) then
bg13.y = bg12.y - bg11.height;
elseif((bg14.y - bg14.height / 2) \> display.contentHeight) then
bg14.y = bg13.y - bg12.height;
elseif((bg15.y - bg15.height / 2) \> display.contentHeight) then
bg15.y = bg14.y - bg13.height;
elseif((bg16.y - bg16.height / 2) \> display.contentHeight) then
bg16.y = bg15.y - bg14.height;
elseif((bg17.y - bg17.height / 2) \> display.contentHeight) then
bg17.y = bg16.y - bg15.height;
end
end
Runtime:addEventListener("enterFrame", moveBG); and the second one is to create lines:
local lines = {}
local lineGroup = display.newGroup()
local prevX,prevY
local isDrawing = false
local i = 1
local function distanceBetween(x1, y1, x2, y2)
local dist\_x = x2 - x1
local dist\_y = y2 - y1
local distanceBetween = math.sqrt((dist\_x\*dist\_x) + (dist\_y\*dist\_y))
return distanceBetween
end
local function drawLine(e)
if(e.phase == "began") then
for i = #lines, 1, -1 do
if (lines[i]) then
lines[i].parent:remove(lines[i])
lines[i] = nil
end
end
lines = {}
line\_number = 1
prevX = e.x
prevY = e.y
isDrawing = true
elseif(e.phase == "moved") then
local distance = distanceBetween(prevX, prevY, e.x, e.y)
if(isDrawing and distance \< 640) then
if(lines[i]) then lineGroup:remove(i) end
lines[i] = display.newLine(prevX, prevY, e.x, e.y)
lines[i]:setColor(255, 255, 0)
lines[i].width = 5
local dist\_x = e.x - prevX
local dist\_y = e.y - prevY
physics.addBody(lines[i], "static", { density = 1, friction = 0.5, bounce = -1.0, shape = {0, 0, dist\_x, dist\_y, 0, 0} } )
lineGroup:insert(lines[i])
end
elseif(e.phase == "ended") then
isDrawing = false
end
end
Runtime:addEventListener("touch",drawLine) Any idea? Thanks! 
[import]uid: 111398 topic_id: 32289 reply_id: 332289[/import]