I never developed in Cocos2D. However, this animated app is not easy to make with regular UIView animation and CAAnimation.
I want a number of UIImageView's (from 1 to 30) to float around the screen with the certain path and I want them to be responsive for touch (they would do some animation when touched). I also need them to go back and forth the screen (new path would be calculated) when they are touched or reach the edge of screen. It's important to retrieve X and Y position of each element whenever needed.
Question is: what Cocos2D classes are best looking at (for a beginner) to make that happen? I've tried UIView animation and CAAnimation but I came across some difficulties so I have a feeling Cocos2D may bring better results. Thank you.
Yes, cocos2d makes it much easier. You want to create a CCSprite with the initWithFile: method. Example:
CCSprite *mySprite = [CCSprite initWithFile:#"fire.png"];
[self addChild:mySprite];
Where fire.png has been added to the project and self is the scene instance.
Related
How do I produce an animation that simulates the burning effect of fire consuming an UIView from top to bottom in Swift?
I found Fireworks, an app that allows users to tweak and try out different settings of CAEmitterLayer with instant results. The effects are great for applying to a whole screen but how would I use it for my purpose - where the UIView must disappear as the fire consumes it from one end to the other?
Is there some tutorial on consuming UIViews with fire using the particle emitter anywhere? I know that I’m supposed to show some code but anything I put here would be irrelevant. I’ve also exhausted my search engine looking for something similar. That’s how I found the Fireworks app actually.
This seems to be a use case that shouldn't be uncommon.
I haven't done much with CAEmitterLayer, so I decided to try my hand at this.
I created a project that does this an posted it on Github. It uses the approach in this Youtube video as a starting point. You can download it here:
FireEmitter project
Here is a small thumbnail of what it looks like:
The project includes a custom subclass of UIView called BurnItDownView
The BurnItDownView is meant to contain other views.
It has one public method, burnItDown(). That triggers the animation.
There are multiple parts to the animation:
A CAEmitterLayer set up to simulate flames burning off a flat surface:
An animation that lowers the emitter layer from the top of the view to the bottom,
A CAGradientView applied as a mask to the view that starts ot fully opaque (with colors of [.clear, .white, .white] and locations of [-0.5, 0, 1] (where the clear color is above the top of the view) and animates the locations property of the gradient view to mask away the view contents from top to bottom. (Animating the locations property to [0, 0, 0], so the entire gradient layer is filled with clear color, fully masking the view's layer.)
Once the view is fully masked, it starts lowering the "birthRate" of the emitter layer in steps until the birth rate is 0. It then holds this step for 2 seconds until all the flame particles have animated away.
Once the flame is fully "extinguised", it resets the locations array to the original value of [-0.5, 0, 1]. This causes an "implicit animation" so the view animates back from the bottom, but quickly
Finally, it resets the emitter layer and emitter cells back to newly a newly created emitter layer and emitter cell to get it ready for the next pass of the animation. (I couldn't figure out how to restore the emitter back to its original state. It was simpler to just create new ones.) It also invokes an Optional completion handler passed to the burnItDown() method. (The app's view controller uses the closure to re-enable the "Burn it down" button.
I was once in your shoe before and came across this Open source library called particle animations.
I would NOT recommend using the library itself since it's deprecated. But I would recommend referring to its source code to get an idea of how to use CAEmitterLayer and CAEmitterCell to make the looks of a Fire!
As you could see from its readme, it has direct examples of Fire. It also states that even Apple and Facebook uses CAEmitterLayer and CAEmitterCell to produce the effect of a fire.
Feel free to ask for more questions.
I'm trying to create an animation where you touch and drag your finger across the screen and colored boxes change size based on your position. Imagine this as a color picker. Here's a gif of the idea. I did this in Corona using a touch event and enterFrame. I can't seem to wrap my head around how to create the same effect in Cocoa Touch.
Where to start with this? I can't seem to find an enterFrame equivalent in Cocoa Touch unless I go with SpriteKit. I'm not making a game, so SpriteKit seems like overkill.
I put a simple animation code on github : https://github.com/MehdiSv/SimpleAnimationColorsPicker
I used a UILongPressGestureRecognizer, and made a CGAffineTransformMakeScale depending on the distance between the touch and each view.
Here is a little preview :
I have been only using Xcode 5 for a little while now and I need help when it comes to auto scrolling a UIScrollView. I am using a single view application. I need the screen to scroll down at a pace that speeds up incrementally. Also I need the screen to keep progressing even when the screen is touched. If someone can explain which code goes where it would be great! Your help will be greatly appreciated. :)
Check out this library: https://github.com/danielamitay/DAAutoScroll
It stops to scroll when the user touches the screen and that's the only solution I see possible. I don't even see why you wouldn't want the user to be able to stop the scrolling..
OK, just adding this from your duplicate question.
I suspect the Piano Tiles game is actually using something like Sprite Kit.
This allows a lot more control over thing like "scrolling" speed.
Instead of using a UIScrollView you would use an SKNode as a layer with the buttons added to that parent layer.
Then using the update game loop you can incrementally increase the speed of the movement based on the time since the game started.
In essence... don't use UIScrollView, don't use UIKit, use SpriteKit.
I can see a few options:
1) suggested by Fogmeister, use Sprite Kit instead.
2) see setContentOffset
3) just use a normal view as parent, then have another child view on top with the full content (would be longer than the parent view), create a NSTimer to periodically call a method which scrolls the child view in whatever direction and speed as required.
Note that might need something on top to mask around the child view from showing the suppose-to-be-hidden sections of the child view.
Hope this helps
I am on the master branch so that it will work with ARC.
I have implemented a method whereby the sprite will scale by a factor of 1.1 when a user touches the sprite. Multiple touches will queue up multiple scaling actions, built on top of each other. Every now and then I get a strange artifact where the smaller version of the sprite shows up on top of the scaled version.
Here's a screenshot:
More background: I'm using a texture atlas so I use:
sprite = [super spriteWithSpriteFrameName:anObject.filename];
to initialize the sprite. Is this a bug in openGL/cocos2d? Any advice on how to stop this artifact?
EDIT:
I am subclassing CCSprite but as far as I can tell there is only one instance of the sprite (the call to super was in a class method). Basically the user will define a list of actions that the sprite will do. The action list can also be interrupted using:
[self stopAllActions]
I've had actions using subclasses of CCMoveBy and CCRotateBy with no issues. It's only the most recent subclass of CCScaleBy that is causing this artifact. In the subclasses of these actions I'm not changing anything in the actions, just tracking certain variables so that I can properly resume the action after the interrupt.
Are you perhaps subclassing CCSprite, and in your subclass did you add a CCSprite instance variable as well?
In that case you'll be showing two sprites. The super class sprite and the instance variable sprite. If the other sprite shows up only sometimes this may depend on the order of adding sprites as childs, or the zOrder property.
Here's my current situation:
I created a CCScene named StoreScene.
Within that scene, I've initialized a CCLayer and just named it Store layer.
Now, I want a scrollable layer that contains content which the user can touch.
To do this, I created another CCLayer named Store Container.
I create an instance of this layer and add it as a child to StoreScene.
In StoreContainer, I've added multiple sprites, each with a unique tag.
The scrolling is done within the StoreScene and touches will move the entire Storecontainer layer up or down.
I have added 4 sprites to my scrolling layer (store container)
Initially,
sprite 1 is located at 0,10
sprite 2 is located at 0,20
sprite 3 is located at 0,30
sprite 4 is located at 0,40
Obviously, as the entire storecontainer layer shifts, the sprite positions shift as well.
However,
when I do this in the TouchesEnded method:
if (CGRectContainsPoint(sprite1.boundingBox, touchpoint)){
NSLog(#"TouchedSprite1");
}
... and so on for each sprite
The touch locations of each sprite remain in the same place!!!
Visually, the sprites are moving up and down nicely.
but their locations when receiving touches stay constant..
is there a reason for this?
Any other way for approaching a scrolling layer?
I've already looked at the UIKit's scrollview and I've looked at CCScrollLayer and both aren't good enough for me.
My way may be simpler but it doesn't work as planned.
Thanks in advance! ^_^
I'm guessing you've implemented touchesEnded in your StoreContainer. In that case the touches' coordinates will be relative to that layer, which explains why their coordinate system is following the layer around the screen. You could implement touchesEnded in the scene instead, or put the StoreContainer instance inside a new and immobile layer whose purpose is only to handle touches.
Alternatively you could keep your current setup and use your answer to this question to get the touch coordinates in the world... :)
Check out CCKit, there is a nice CCScrollLayer implementation included.