Cocos2d-iPhone: CCSprite positions differ between Retina & non-Retina Screens
- by bobwaycott
I have a fairly simple app built using cocos2d-iphone, but a strange positioning problem that I've been unable to resolve. The app uses sprite sheets, and there is a Retina and non-Retina sprite sheet within the app that use the exact same artwork (except for resolution, of course). There are other artwork within the app used for CCSprites that are both standard and -hd suffixed.
Within the app, a group of sprites are created when the app starts. These initially created CCSprites always position identically (and correctly) on Retina & non-Retina screens.
// In method called to setup sprites when app launches
// Cache & setup app sprites
[[CCSpriteFrameCache sharedSpriteFrameCache] addSpriteFramesWithFile: @"sprites.plist"];
sprites = [CCSpriteBatchNode batchNodeWithFile: @"sprites.png"];
hill = [CCSprite spriteWithSpriteFrameName: @"hill.png"];
hill.position = ccp( 160, 75 );
[sprites addChild: hill z: 1];
// ... [create more sprites in same fashion]
// NOTE: All sprites created here have correct positioning on Retina & non-Retina screens
When a user taps the screen a certain way, a method is called that creates another group of CCSprites (on- and off-screen), animating them all in. One of these sprites, hand, is always positioned identically (and correctly) on Retina & non-Retina screens. The others (a group of clouds) successfully create & animate, but their positions are correct only on Retina displays. On a non-Retina display, each cloud has incorrect starting positions (incorrect for x, y, or sometimes both), and their ending positions after animation are also wrong.
I've included the responsible code below from the on-touch method that creates the new sprites and animates them in. Again, it works as expected on a Retina display, but incorrectly on non-Retina screens. The CCSprites used are created in the same way at app-start to setup all the initial sprites in the app, which always have correct positions.
// Elsewhere, in a method called on touch
// Create clouds
cloud1 = [CCSprite spriteWithSpriteFrameName: @"cloud_1.png"];
cloud1.position = ccp(-150, 320);
cloud1.scale = 1.2f;
cloud2 = [CCSprite spriteWithSpriteFrameName: @"cloud_2.png"];
cloud2.position = ccp(-150, 335);
cloud2.scale = 1.3f;
cloud3 = [CCSprite spriteWithSpriteFrameName: @"cloud_4.png"];
cloud3.position = ccp(-150, 400);
cloud4 = [CCSprite spriteWithSpriteFrameName: @"cloud_5.png"];
cloud4.position = ccp(-150, 420);
cloud5 = [CCSprite spriteWithSpriteFrameName: @"cloud_3.png"];
cloud5.position = ccp(400, 350);
cloud6 = [CCSprite spriteWithSpriteFrameName: @"cloud_1.png"];
cloud6.position = ccp(400, 335);
cloud6.scale = 1.1f;
cloud7 = [CCSprite spriteWithSpriteFrameName: @"cloud_2.png"];
cloud7.flipY = YES;
cloud7.flipX = YES;
cloud7.position = ccp(400, 380);
// Create hand
hand = [CCSprite spriteWithSpriteFrameName:@"hand.png"];
hand.position = ccp(160, 650);
[sprites addChild: cloud1 z: 10];
[sprites addChild: cloud2 z: 9];
[sprites addChild: cloud3 z: 8];
[sprites addChild: cloud4 z: 7];
[sprites addChild: cloud5 z: 6];
[sprites addChild: cloud6 z: 10];
[sprites addChild: cloud7 z: 8];
[sprites addChild: hand z: 10];
// ACTION!!
[cloud1 runAction:[CCMoveTo actionWithDuration: 1.0f position: ccp(70, 320)]];
[cloud2 runAction:[CCMoveTo actionWithDuration: 1.0f position: ccp(60, 335)]];
[cloud3 runAction:[CCMoveTo actionWithDuration: 1.0f position: ccp(100, 400)]];
[cloud4 runAction:[CCMoveTo actionWithDuration: 1.0f position: ccp(80, 420)]];
[cloud5 runAction:[CCMoveTo actionWithDuration: 1.0f position: ccp(250, 350)]];
[cloud6 runAction:[CCMoveTo actionWithDuration: 1.0f position: ccp(250, 335)]];
[cloud7 runAction:[CCMoveTo actionWithDuration: 1.0f position: ccp(270, 380)]];
[hand runAction: handIn];
It may be worth mentioning that I see this incorrect positioning behavior in the iOS Simulator when running the app and switching between the standard iPhone and iPhone (Retina) hardware options. I have not been able to verify this occurs or does not occur on an actual non-Retina iPhone because I do not have one.
However, this is the only time I see this odd positioning behavior occur (the incorrect results obtained after user touch), and since I'm creating all sprites in exactly the same way (i.e., [CCSprite spriteWithSpriteFrameName:] and then setting position with cpp()), I would be especially grateful for any help in tracking down why this single group of sprites are always incorrect on non-Retina screens.
Thank you.
