Dividing screen into two parts for iphone box2d game application - iphone

The concept is like i have 10 balls and one by one ball should come in between so i can do some action on it and remaining balls it should show at bottom. But I can not divide my screen into two parts to get the balls at bottom. I basically want to show all remaining balls at bottom where it should not collide or anything it will be just a display.
I have CCColorLayer extended class which I'm using to create game.
Can anyone please help me with it?
Thank you,
Ankita

That should be simple to do since Box2d won't touch any Cocos2d elements unless you manually create a connection between a Cocos2d element and Box2d element. Among the most common is to connect a CCSprite to a b2Body by updating the sprite's position to follow the body's position after Box2d finished simulating the world after each time step.
So for your case, you can just leave the balls at the bottom as sprites only, meaning don't assign a b2Body to it yet. Other b2Body will just ignore the bottom balls. Then when it's time for the ball to enter the game stage, assign a b2Body to it and connect the sprite and body together, and voila the balls will start having collisions!
That's all I can answer based on what you wrote in the question. If you need more details, perhaps you should ad a mock-up like HanClinto commented, or post up your codes here.

Related

Side scroller style scene with gravity

I've started learning sprite kit and I think I've got the basics but now I'm struggling with something.
I want to create a game that has a 'Streets of rage' type feel to it whereby the user can move up and down, but isn't jumping, they're still on a 2D plane. But I also want them to be effected by gravity e.g stairs etc. like the following picture.
Am I right in assuming that I should have my background image with colliders around the blue and brown edges, and then create a physicsbody collider located at the feet of my player/players so that it looks like they can move against the background, but when their feet reach the top it would stop?
Could I then place other obstacles like rocks etc on that path that they would be able to collide into, but that could also sit over the path and the sky? How would I handle the fact that these could be constantly colliding depending on the position?
I appreciate there isn't any code here, but I'm trying to understand the concept around this before I jump in coding a solution.
Thanks
I would use a categoryBitMask to separate the different planes of objects.
And I would play with collisionBitMask/contactTestBitMask depending from the plane the player is in, in addition to the z-order.
Thus you can have a rock that collides your player if they are both in the same line else the player would walk behind/front.

Breaking up a sprite in cocos2d

I'm making a 2D plane fighting game for the iPhone in cocos2d. I'm trying to make it so when you shoot an enemy plane, it breaks into a couple of separated pieces that will fall out of sight. What is generally the best practice for breaking one sprite up into many? should I create new images for each separate piece, or treat the initial image like a sprite sheet, and make a new sprite from segments?
Please look at this tutorial
It makes a grid of points then moves the internal (not-edge) ones around randomly a bit so it's not all perfect triangles. Then each update it moves/rotates the triangles separately--then draws them all at once.
You treat the whole thing as a sprite, so can run any of the usual actions on it. This example uses CCMoveBy to move the whole group down off the bottom.

Create a space environment with no gravity, Box2d or not?

I want to create a cclayer with 4-5 flying objects, flying in random directions on screen. I also want those flying objects transparent to each other, which means they can fly through each other.
What I can think of Ways to do:
With Box2D
Create a box2d world with 0 gravity. and add Polygon static ground around the edges of the screen.
Give an initial force to each of the flying objects, let them flying around and reflect on the grounds.
Problems: Objects still rest down after sometime.. Don't know why. Objects collide with each other, don't know how to make them fly through each other.
Without Box2D
use CCMove for each objects, detect if they reach edge of the screen, calculate new path for their move..
Can someone point me a direction, which way is easier? Thanks a lot.
If you have to handle complex collisions - go with Box2d. If your collisions are simple - handle them yourself.

Creating a Body - Cocos2d/Box2d

I have a ball and another sprite. When the ball collides with the sprite it simulates falling.
My only problem is the other sprite is just on big image and the ball is on top of it, but there are spaces on the sprite and a lot of corners. I need to determine if the sprite has touch one of the corners. I know this is hard to understand.
So, my question is, is it possible to make a body without
b2PolygonShape blockShape;
and
blockShapeDef.shape = &blockShape;
OR
is there an alternative I can use? I cannot set the image as a box and it would take way to long to set edges because there are so many corners.
I have already set up the collision detection.
I really need help with this.
Thanks!
If you want it to react properly, you have to make a polygon using every single corner coordinate.
But don't be lazy about it. You can use SpriteHelper for creating *b2PolygonShape*s out of your sprites.
Or another alternative: VertexHelper

Cocos2d - Creating collidable Sprites?

Hello everyone I an very new to cocos2d, so I apologize if this is a simple question. I would like to create to sprites that collide when they hit each other.
For instance, one sprite, spriteA, is in a fixed position on the screen. And another sprite, spriteB, is moving around the screen. SpriteB will collide with spriteA. If that doesn't make sense or you don't understand it, tell me and I will elaborate further. Any help is appreciated. Thank YOU!
Try using Chipmunk or Box2d physics systems. These are included with Cocos2d and work by having a physics simulation that updates with every time the graphics change on screen.
The physics simulation will tell you if two objects are overlapping, and will provide physical attributes like weight, slipperiness (friction), speed and direction, which creates reactions like bouncing, sliding, realistic loss of speed and changes of direction on impact.
If you are new to physics simulation, here's a 30 second run down:
Create "bodies" in the physics simulation that represent each graphical sprite
Bodies are usually defined more simply than their graphical counterparts, like a circle, square or simple polygon shape
In order to update the graphics on the screen accurately, first you establish a pixels to meters ratio. Meters are notional (i.e. made up) measurement that is used in the physics sim
Each time the physics simulation "ticks", you update the graphics on screen accordingly
So if a body in the physics sim moves 1 meter, you might transform the pixel sprite 32 pixels
Here's a good tute on collision detection using Box2d.
http://www.raywenderlich.com/606/how-to-use-box2d-for-just-collision-detection-with-cocos2d-iphone
enjoy
Its actually very simple:
Just schedule a timer: [self schedule:#selector(checkForCollision:)];
Specify the method: - (void)checkForCollision:(ccTime)dt {}
In the curly braces, make CGRects for each sprite using CGRectMake.
Then in the same method, just call: if (CGRectIntersectsRect) {}
That easy!
Well technically speaking when the 2 sprites interact, or share at least one common point, then they are colliding. I'm a little confused by your question. Are you asking for direction on how to make the sprite move on screen, or are you asking how to handle the actual collision(such as calling a method if they collide)?