I am newbie in IOS Gaming, and i need to create a game using Sprite Kit framework for functionality similar to angry bird pulley system, and also wants to find the distance the object is travelled from the pulley to its landing.
Can anyone help me out with this, i would be thankfull for it.
Thanks in advance.
One way you could code a slingshot effect would to use a starting point on the screen at let's say (x=100,y=100). You would display a SpriteNode of a slingshot with the Y centered at the (100,100).
The next step would be to use touchesBegan:withEvent: in the area of the slingshot to let your code know the player is looking to shoot the slingshot.
You would use touchesMoved:withEvent: to track how far back (how much tension) the player is pulling back from the slingshot.
The release would be triggtouchesEnded:withEvent. Based on how far the touch began (x=100) and how far back is was released (for example x=30), you can apply force like this:
float forceUsed = startTouchX - endTouchX;
[_projectile.physicsBody applyForce:CGVectorMake(forceUsed, 0)];
If you are looking to angle the shot you would also have to track Y and use that variable instead of the 0 above.
As for calculating distance between 2 points on the screen, it boils down to x and y coordinates. Subtract objectA.position.x from objectB.position.x
Things can get a lot more complex of course but that all depends on what you want to do in your code. Hope this helps.
P.S. The touches above are all part of the UIResponder Class.
Related
i'm new in the development of swift ios game using spirtekit and i need help. I want to develop a vertical 2d endless run, where with a swipe you are able to move the player in direction and if there is an obstacle, it is created in a position calculate with the position of the player. Once create the obstacle i would like to make it falling down but alway with the same relation with the player (this means that it has to move only on y axis).
Can you suggest me some ideas on how to manage this?
This book teaches you exactly how to make what you are looking for:
https://www.amazon.com/Getting-Started-SpriteKit-Jorge-Jordan-ebook/dp/B01891X7TM
This is the end product:
https://itunes.apple.com/lr/app/inside-the-hat/id1076967804?mt=8
You can get it for free here (with trial):
https://www.packtpub.com/application-development/getting-started-spritekit
The source code for this is around somewhere on the web, but I forgot where :( I bought the book a year ago and can't find it now.
Basically, you have a long background that is .moveTo .. in .update you check the position of the background, then reset it based on its XY position (it basically just goes all the way down, warps to the top position, then falls)
Also in .update you check for score, or a timer, or just a random check, then spawn an enemy, obstacle, etc. You give the enemy / obstacle SKActions to move towards the player, and let .didBegin(contact:) handle scoring, sound effects, death, etc.
If I have a sprite node, just a white circle somewhere on the screen, how am I able to make it so when I drag, let's say downwards and slightly to the left, the circle sprite would launch upwards and to the right and then gradually come down, like a golf shot.
Another way of explaining the mechanic is the Angry Birds game, where you launch the birds of the slingshot, the birds move in the opposite direction of your drag and gradually come down.
For another live example of the mechanics of the circle, look at the app, Desert Golfing.
Thanks, and if you don't know what I mean just comment and I'll try to explain it better.
OPTIONAL: If you do know how to do the slingshot type mechanic for the circle, do you also know how to add an arrow to the screen so users know which way the circle will launch?
Ill try to break your problem down into small steps that you could then solve yourself:
Detect the swipe:
use a UIPanGestureRecognizer. You will be able to implement a method that is called whenever a user drags their finger in a certain direction.
Here are some good references:
- Pan Gesture Official Documentation
- A very useful question that can serve you as a guide
Detect the magnitude of the swipe in order to impart an impulse
Check out the second link above. What you have to do is in the method for the gesture recognizer you will detect certain flags such as when the user starts the pan or ends the pan. Then, you can check for the location at those moments. With the Pythagorean theorem you should be able to get the distance and use that as the magnitude.
Apply impulse:
Create a physics body for your sprite and then make sure that you have gravity set inside your physics world. This allows the sprite to move in a parabolic motion. Then, use applyImpulse: on your physics body with your magnitude.
Regarding the arrow, you can easily do some delegation from within your pan gesture handler that gets the magnitude of the swipe and projects a reflection that your arrow will then show. Your question is pretty loaded so going into more detail is impossible, but best of luck. Hope this helps!
I am making a basic app that pushes shapes across the screen and detects collision with Sprite Kit. My first attempt was using moveTo on the nodes. The issue I had was with collision, the objects would rotate around each other instead of bounce.
Therefore I found I need to use applyForce OR applyImpulse.
In this situation I have a circle for example that is position off screen at its start of life. We then determine a target exit point, and want to 'flick'/'push' the node in that direction.
I cannot figure out how to applyImpulse towards the target end position I have as a CGPoint. I need to get this to a CGVector but I am not sure what needs to be done. I had a look around and found some Ray tuts but they just show applyForce or moveTo. I am not sure how to calculate this.
I found a site that explains 2D physics well.
http://www.rodedev.com/tutorials/gamephysics/
With this I worked out what the angle needed to be and have a speed that I can control and it works well.
You can move an object by changing manually the x and y position so you can reach your end point. In the update function you change yourObject.position.x and yourObject.position.y if I have understood correctly your question. If not please be more explicit. Hope that helps.
I am making a game using cocos2d and SpriteBuilder. There is a hero sprite and coins, that should be collected by him. That's a horizontal scrolling game, so every time hero touches a coin, this coin changes it's x-coordinate 2000px to the right and new y-coordinate is generated at random. Using update method I move it to the visible area as a "new" coin. But when hero flyies by and doesn't collect it ,coin must change coordinates only when it's already off the screen, so I tried this solution:
-(void)update:(CCTime)delta{
_coin.position=ccp(_coin.position.x - delta * scrollSpeed, _coinY);
if (CGRectIntersectsRect(_hero.boundingBox,_coin.boundingBox)) {
_coinY=arc4random() % 801 + 100;
_coin.position=ccp(_coin.position.x + 2000.f,_coinY);
}
else if(_hero.position.x >= _coin.position.x + 150){
_coinY=arc4random() % 801 + 100;
_coin.position=ccp(_coin.position.x + 2000.f,_coinY);
}
It works,but after that I found a small bug(I am not sure, whether it's related to this code) : sometimes, when hero touches coin, hero is like pushed away to the left. I have no idea why.
How to fix it?
Is that way, that I am using for coin ,right?
I see 2 issues with your approach:
1. Hero bounces of the coin.
To fix this you need to make your coin a sensor. This way you will still be notified about collisions, but the hero will simply pass through the coin without actually hitting it.
I'm not sure if you can set this in SpriteBuilder, but probably you can enumerate all coins after loading the scene and set sensor property to YES:
coin.physicsBody.sensor = YES;
Things like this is one of the reasons I believe you first need to learn pure Cocos2D and only then use tools making your life easier such as SpriteBuilder. Which is a great tool, but in some cases you still need know what happens behind the scenes.
2. You're mixing physics with things like CGRectIntersectsRect
If you're using physics engine you need to detect collisions via collision delegate and not by checking CGRectIntersectsRect in update:.
It is hard to explain how to do this in a few sentences, so here is a nice tutorial that shows how to detect collisions in Cocos2D v3 and of course there is a chapter about this in my book.
By the way you shouldn't use update:at all when manipulating physics nodes, use fixedUpdate: instead.
I hope this will help you to solve your issue.
Hi fellow programmers!
What I'm trying to do:
I have an image placed in the center of the screen. When I put my finger on this image, and rotate my finger, the image should rotate as well. When i release the finger, i would like the image to decelerate for x period of time. (Let's say that it should decelerate slowly). Basically I'm trying to develop a Spin-the-bottle application, but I can't figure out the velocity part.
What I've tried:
I've used this to get the one finger rotation, and it works great so far, but it doesn't include the velocity part. And honestly, I have no idea, how to calculate the velocity.
What I'm asking of you:
A "simple" way of doing one-finger-rotation with velocity, of an UIImageView in a normal UIViewController. (Or just using this method to the rotation part, and somehow implement velocity.) Examples are appreciated!
If you have any questions, please comment!
Thanks in advance. :)