Class and Example for Parallax Background

Teranth

Hey guys, here is a class I put together after reading an example of Parallax Backgrounds by Adnaan--all the actual code credit goes to him, but I have cleaned up the code a little and packaged it as a class with some extra options that others might find useful in their games. So I decided to share it as well. Enjoy

To use it you will need a simple table with the images to use like the following, after that it's a sprite you can do what you want with in the game:

-- Setup background images to use. local bgs = { bg1 = "bg1.png", bg2 = "bg2.png" }   -- Create a new Parallax background sprite with a speed of 5 local bg = ParaBG.new(bgs, 5)   -- Add background to scene--should be done before any -- sprites/controls so it's behind everything. stage:addChild(bg)

For Adnaan's post: http://giderosmobile.com/forum/discussion/387/parallax-background

unlying

is there any way to change speed dynamically?

gaboritaly

Thanks @Teranth >-

Teranth

@unlying absolutely Here is an example of the two speed functions setSpeed() and getSpeed() I needed the same functions for my runner setup--boost power ups, etc--I used a timer to control the background speeds.

-- Setup background images to use. local bgs = { bg1 = "bg1.png", bg2 = "bg2.png" }   -- Create a new Parallax background sprite with a speed of 5 local bg = ParaBG.new(bgs, 5)   -- Add background to scene--should be done before any -- sprites/controls so it's behind everything. stage:addChild(bg)   -- Change the speed of the background scrolling to 8 pixels per frame. -- Far background will be set to 2 pixel per frame. (This is twice the default speed) bg:setSpeed(8)   -- The far background is set to move at 25% of the main background speed and will be set as well to keep the ratio intact.   -- Also if you need to get the current background speed in use you can get it with: local current_bg_speed = bg:getSpeed() print(current_bg_speed)

@gaboritaly you are very welcome, I am glad someone will find it useful

unlying

@Teranth great!

bravcm

Thanks!

GGGRRR123

and how to make background moving vertically?

fxone

hi @GGGRRR123, there is an original idea with vertical example, you can easy adapt this to @Teranth's class:
http://giderosmobile.com/forum/discussion/387/parallax-background

mikiex

I noticed there was a glitch visible when semi transparent sprites are used.
changing the order at which things happens seems to fix it.

self.bgFarY = 0 self.bg1:setX(self.bgFarY) --put this before the line above   .............   self.bgNearY = 0 self.bg3:setX(self.bgNearY)--put this before the line above

Jojojohn

@Teranth, I copied your code yet there's an error saying about ParaBG?

xGuilt

Is there a way to make it appear continuous?
I mean, i'm using 2 different images as a scrolling background and when the first background's far X reaches 0 it automatically recreates the first background even when the 2nd background is still scrolling. I dunno it kinda feels like it's just teleporting?