Moving Platforms? Cocos2d and Tiled

Question 1

Here is the (kind of) step by step of how I got my moving tiles working, this is only related to the moving tiles, and nothing else.

Note: You will need to run this as a release (not debug) in order to get everything running smoothly, and not having your character fall through the ground.

In the interface I created these variables:

@interface HelloWorldLayer(){
    CCTMXTiledMap *map;
    BOOL goingDown;
    int moveCount;
}

The CCTMXTiledMap is the instance of my map. The BOOL and int are two variables I use to keep track of my moving tiles.

-(id) init {
    if( (self=[super init]) ) {
         // add our map
         map = [[CCTMXTiledMap alloc] initWithTMXFile:@"level1-1.tmx"];
         map.position = ccp(0,0);
         [self addChild:map];

         //add our moving platforms layer
         movingTiles = [map layerNamed:@"moving_platforms"];

         //set the variables I use to keep track of the moving platforms
         goingDown = true;
         moveCount = 0;

         //schedule my update method
         [self schedule:@selector(update:)];
    }
    return self;
}

After the init method, I then create my move platforms method:

-(void)movePlatforms: (ccTime) dt{
    if(goingDown){
        moveCount++;
    }else{
        moveCount--;
    }
    CGSize s = [movingTiles layerSize];
    for( int x=0; x<s.width;x++) {
        for( int y=0; y< s.height; y++ ) {
            CCSprite *tile = [movingTiles tileAt:ccp(x,y)];
            if(goingDown){
                CGPoint newPosition = ccp(tile.position.x, tile.position.y - 1);
                tile.position = newPosition;
                if(moveCount >= 100){
                    goingDown = false;
                }
            }else{
                CGPoint newPosition = ccp(tile.position.x, tile.position.y + 1);
                tile.position = newPosition;
                if(moveCount <= 0){
                    goingDown = true;
                }
            }
        }
    }
}

So this is where the magic happens, I use methods I got from here, and the gentleman Mauricio Tollin told me I could update a tile position rather than destroy and recreate them.

So I iterate through every tile in my moving platforms layer, and tell them to go down 1 every call, until moveCount >= 100, then it says goingDown is now false, and it switches its direction. From there it just goes back and forth, counting to 100, and then back down.

If you want it to move longer, just increase 100 to 200 or whatever you want. (Or you can use a check to detect collision, and when it collides with a specified sprite, you can have it change then. If that is more of what you want, use this).

if (CGRectIntersectsRect([someSprite boundingBox], [someSprite boundingBox])) {
    //Do something
}

After all of that, I create my update method:

-(void)update:(ccTime)dt{
    [self movePlatforms:0.1];
}

In the init method it schedules the update method to be called every frame, and then the update method will run the movePlatforms method (or any other function that needs to be checked frequently, such as hazard detection, etc).

You can also make the platforms move slower by changing the time passed into movePlatforms, or you can schedule a slower update interval in the init method.

I hope this helps someone out in the future, I just wanted to create this answer with a more in depth process of how I got this working, since my question post was really unorganized and heavily edited while I was learning.

Question 2

Creating and removing tiles will effect your performance. Instead of it, try to move the tile changing their position:

CCSprite *tile = [movingTiles tileAt:ccp(92,platformY)];
[movingTiles removeTileAt:ccp(92,platformY)];
CGPoint newTilePosition = tile.position;
if (goingDown){
    newTilePosition.y ++;
    if(newTilePosition.y >= 20){
        goingDown = false;
    }
}else{
    newTilePosition.y --;
    if(newTilePosition.y <= 10){
        goingDown = true;
    }
}
tile.position = newTilePosition;