Scrolling Background with Cocos2D and Box2D - cocos2d-iphone

I am trying to create a simple game that mainly consists of a ball rolling down an incline. The player's only control is to cause the ball to jump. My question is, what is the best way to make it appear to roll while generally keeping the ball at the same place on the screen? I have considered CCCamera, but it seems like it's not the best option since I want a repeating background image. Scrolling the background manually is also giving me trouble because it's not clear how to get the ball to stay in one place while letting Box2D handle the physics. I'd appreciate any help as I've been stuck on this for quite a while.

Use CCFollow on the layer where you draw the game stuff, and let it follow the ball sprite:
[gameLayer runAction:[CCFollow actionWithTarget:ball]];

Related

Pygame: Character Centered Movement System (Diablo II like click-to-move)

I am currently working on a new RPG game using Pygame (my aim here is really to learn how to use object oriented programming). I started a few days ago and developed a movement system where the player clicks a location and the character sprite goes to that location and stops when it get's there by checking if the sprite 'collides' with the mouse position.
I quickly found however that this greatly limited the world size (to the app window size).
I started having a look into making a movement system where the background would move with respect to the player, hence providing the illusion of movement.
I managed to achieve this by creating a variable keeping track of my background map position. The map is much bigger than the app window. And each time I want my player to move I offset the background by the speed of the player in the opposite direction.
My next problem now is that I can't get my character to stop moving... because the character sprite never actually reaches the last position clicked by the mouse, since it is the background that is moving, not the character sprite.
I was thinking of spending some time coding in a variable that would keep track of how many displacements it would take the character sprite to reach the mouse clicked position if it was to move. Since the background moves at the character sprite's speed it would take as many displacement of the background in the x and y directions to center the clicked position on the background to the character sprite at the center of the screen.
It would be something like that:
If MOUSEBUTTON clicked:
NM = set number of moves needed to reach the clicked position based on character sprite distance to click and character sprite speed.
If NM != 0:
Move background image
Else:
pass
This would mean that when my background has moved enough for the character sprite to now be just over the area of the background that was originally clicked by the player, the movement would stop since NM == 0.
I guess that my question is: Does that sound like a good idea or will it be a nightmare to handle the movement of other sprites and collisions ? And are there better tools in Pygame to achieve this movement system ?
I could also maybe use a clock and work out how many seconds the movements would take.
I guess that ultimately the whole challenge is dealing with a fixed reference point and make everything move around it, both with respect to this fixed reference, but also to their own. e.g. If two other sprites move toward one another, and the character of the player also "moves" then the movement of the other two sprites will have to depend both on the position of the other sprite and also on the offset of the background caused by the movement of the player's character.
An interesting topic which has been frying my brain for a few nights !
Thank you for your suggestions !
You actually asking for an opinion on game design. The way I look at it, nothing is impossible so go ahead and try your coding. Also it would be wise to look around at similar projects scattered around the net. You may be able to pick up a lot of tips without re inventing the wheel. Here is a good place to start.
scrolling mini map

Best way to have animated background in cocos2d

I have seen some similar questions asked but no definitive answer.
I have a background image that I'm using for my main menu for a cocos2d game. I plan to have it animated but not sure what is the most efficient way to do this. One idea was to have multiple images to create the animation but I was thinking this may take up too much memory as each image would be quite big.
The other idea was having one background image as a sprite and then having child sprites of that image that are animated with ccaction. The only thing is I may not be able to create such an elaborate animation if I do this.
I just wanted to get some feedback on this to see what would be the best approach.
Thank you,
Making a frame-by-frame animation of the whole screen would make your app size litteraly explode.
You should definitely go with your 2nd idea, i.e have different sprites for each animated component and use actions to animate them.
Check out CocosBuilder: it provides a nice UI for designing such complex animations

Particles around a sprite

I'm new to the CoCos2D development. I have checked out some tutorials and went on trying to develop a little idea.
I have checked some partical tutorials and it all looks nice but I still have some questions about it. I have seen how to call a particle and let it follow wherever you click on the layer and so on but I need something more.
Let's say I have several circle shaped sprites on my Layer. Is it possible to do the following: click on a sprite and then a partical trail should go around the sprite so you as a player can see it is selected. The particale should keep circling around the sprite until I select another circle shaped sprite which result in dissappearing of the previous particle trail and appearing onto the new selected sprite.
Is this possible with the particle system or should I look for another way of doing this ? Any type of help is appreciated.
kind regards

Achieve Infinite Scrolling for a platformer game using cocos2d language objective c

I am trying to develop an 2D game using cocos2d library. I am still learning the framework.
Please understand that I am new to game development but not new to programming using objective c.
Here is the issue I am facing when it comes to my game development effort - I feel that I am missing the theoretical understanding of how to develop an infinite scrolling game. Is it possible for any of you to provide me some guidance on that ?
Here is my understanding of achieving infinite scrolling using cocos2d framework:
Cocos2d has a singleton director class which handles the current scene and scene transitions
In the current scene, I feel like I have to create an platform object consisting of several images and add them as a child to the current layer. And constantly run a move action to the platform sprite. So as and when I detect a particular image is off screen I have to replace it with another image. That way I will be able to create an infinite scrolling.
I am sorry if point 2 is not coherent. I just attempted to put my understanding of how to infinite scrolling.
Can you please help me with this ?
Thanks
I dissected how to implement scrolling with cocos2d-iphone in this article. What you probably want is the "fake scrolling" approach where two background images are moved and switch position after one completely left the screen.
You want to do this for the background layer only, not individual sprites. Your world isn't really moving, it's just the background panning that creates the illusion of movement. All sprites etc (player, enemies) movement is still relative to screen coordinates.
You'll find a working implementation in the code for my Learn Cocos2D 2 book in the Shoot'em Up project.
If you don't want to bother implementing this yourself, KoboldTouch supports endless/infinite scrolling for tilemaps. Here the game objects actually move along with the background infinitely (up to the maximum coordinates supported by float which is around +/- 16 million points).

Sprite does not jump when moving

I'm making a platform game, and everything was great. My sprite moved when i touched the left side of the screen, and jumped when i touched the right side. But then i decided to make it move by itself. so i added the ccmoveto function, but now it does not jump! I'm new to cocos2d but everything is working ok, except this, already searched but couldn't find the answer can someone please help me?
I tried everything, but it only jumps if i delete the ccmoveto action.
I'm using cocos2d 2.0
Thank you!!
CcMoveTo will override any manual position changes, inluding changes from other actions like CCJump. Your character is set to move to destination in a straight line, no matter what.
It's issues like these why I always recommend not to use actions for gameplay logic. Especially position, you need to retain full control over it. Use a direction vector and integrate position every update: and you're free to do everything you need.
my advice is to use one of the physics engines provided with cocos2d: Box2D and Chipmunk physics. Thanks to this engines you can define the characteristics of the world (i.e. gravity vector) a shape and a mass for your sprite (i.e. a rectangle with a weight). Then when you need it to jump you will just create a force vector with the characteristics you need (i.e. angle, etc.) and keep updated your sprite with its physical body. This will make your sprite jump and land quite realistically.