ParallaxBackground allows you to integrate a parallax scrolling effect in your SpriteKit games.
It is really easy to integrate the parallax background into your project. You just need to copy the files PBParallaxBackground.m and PBParallaxBackground.h in your Xcode project.
You should initialize and insert the PBParallaxBackground in the scene initialization:
NSArray * imageNames = @[@"pForeground", @"pMiddle", @"pBackground"];
PBParallaxBackground * parallax = [[PBParallaxBackground alloc] initWithBackgrounds:imageNames size:size direction:kPBParallaxBackgroundDirectionLeft fastestSpeed:kPBParallaxBackgroundDefaultSpeed andSpeedDecrease:kPBParallaxBackgroundDefaultSpeedDifferential];
self.parallaxBackground = parallax;
[self addChild:parallax];
You must specify a NSArray of either images, NSStrings (containing valid image names included in the bundle), SKSpriteNodes or SKTextures.
"direction" represents the direction of the parallax movement, and can be either kPBParallaxBackgroundDirectionUp, kPBParallaxBackgroundDirectionDown, kPBParallaxBackgroundDirectionRight or kPBParallaxBackgroundDirectionLeft.
the fastestSpeed refers to the speed of the fastest element. Nice values are between 1 and 4.
the speedDecrease is a number between 0 and 1. The bigger the speed decrease, the slower each layer of the parallax will go. A speed decrease of 0 means no speed decrease (i.e: all layers will move at the same speed) whereas a speed decrease of 1 means that every layer will move at half the speed of the immediatly faster layer.
Then in your scene update method, you just need to call:
-(void)update:(CFTimeInterval)currentTime {
...
[self.parallaxBackground update:currentTime];
}
It is that simple. If you find it useful, please let me know. Thanks!
Now there is a quick and fancy way to reverse the movement, which can be really interesting for a game. You just need to invoke:
[self.parallaxBackground reverseMovementDirection];
And it will reverse the parallax scrollin (from left to right, from right to left, from up to down or from down to up). It has been implemented in the touchesBegan method of the scene for testing purposes, so you just have to touch the iPad or iPhone to change the direction.
The MIT License (MIT)
Copyright (c) 2013 Ignacio Nieto Carvajal
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