Moving a sprite across multiple coordinates using CCSequence

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Moving a sprite across multiple coordinates using CCSequence

(5 posts) (3 voices)

Started 3 months ago by noodlz
Latest reply from Thomvis

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noodlz
Member

Hello! Long time reader, first time poster.

I have a predefined set of coordinates which form a path stored in two NSMutableArrays (one containing the x values, one for the y values). There are roughly 40 sets of coordinates.

Below is the section of code I am currently using:

id patrolAction;
int pat_x1, pat_y1;
CCSequence *moveSequence;

for (int x = 0; x<[patrolPathX1 count]; x++){

pat_x1=[[patrolPathX1 objectAtIndex:x]intValue];
pat_y1=[[patrolPathY1 objectAtIndex:x]intValue];

patrolAction = [CCMoveTo actionWithDuration:1.5 position:[self positionForTileCoord:CGPointMake((float) pat_x1, (float) pat_y1)]];

moveSequence = [CCSequence actions:patrolAction, nil];

[enemy2 runAction:moveSequence];
}

The aim is to get the sprite (enemy2) to move along this predefined path, however the sprite is just moving across to the final set of coordinates straight away. When I take out the for loop and hardcode them individually, it works fine.

(When I put the "runAction" outside of the for loop, the same effect is produced)

I have tried putting in a CCDelayTime in the sequence, yet this doesn't seem to help.

Can anyone help me out with this issue?

Thanks in advance :)

Posted 3 months ago #
Thomvis
Member
You call runAction for each individual coordinate. All CCMoveTo actions are executed simultaneously, instead of in sequence (to be more precise: all CCSequences containing one single CCMoveTo action are executed simultaneously). What you want is to have one big CCSequence with all the CCMoveTo actions in it. You can achieve that with the following code:
```
int pat_x1, pat_y1;
CCAction *moveSequence = nil;

for (int x = 0; x<[patrolPathX1 count]; x++){

pat_x1=[[patrolPathX1 objectAtIndex:x]intValue];
pat_y1=[[patrolPathY1 objectAtIndex:x]intValue];

CCMoveTo *patrolAction = [CCMoveTo actionWithDuration:1.5 position:[self positionForTileCoord:CGPointMake((float) pat_x1, (float) pat_y1)]];
if (moveSequence != nil) {
 moveSequence = [CCSequence actionOne: moveSequence two: patrolAction];
} else {
moveSequence = patrolAction; //the first action
}

}
[enemy2 runAction:moveSequence];
```
At the end of the loop, you have a single action containing all the CCMoveTo's to run. Note that you actually create a kind of tree structure of actions, because each CCSequence has two child actions: a CCSequence child-action (containing a CCSequence and CCMoveTo) and a CCMoveTo. This is similar to what happens when you create a CCSequence with variable arguments.

Final note: I didn't test it, there might be stupid syntax errors or even worse. Also, I assumed you are using ACR, so I did no memory management.
Posted 3 months ago #
noodlz
Member

Thanks very much Thomvis! Works perfectly :)

Posted 3 months ago #

rickms
Member

Here is an alternative solution

int pat_x1, pat_y1;
NSMutableArray *moveActions = [NSMutableArray arrayWithCapacity:[patrolPathX1 count]];

for (int x = 0; x<[patrolPathX1 count]; x++){

    pat_x1=[[patrolPathX1 objectAtIndex:x]intValue];
    pat_y1=[[patrolPathY1 objectAtIndex:x]intValue];

    [moveActions addObject:[CCMoveTo actionWithDuration:1.5 position:[self positionForTileCoord:CGPointMake((float) pat_x1, (float) pat_y1)]]];

}

[enemy2 runAction:[CCSequence actionsWithArray:moveActions]];

Also, an alternative method of storing the coordinates would be 1 array of NSValues, which can be used to store a CGPoint.

Posted 3 months ago #

Thomvis
Member

Oh, yeah, that makes more sense. The version of cocos2d I am using in my current project and used to come up with my solution didn't have that yet. That said, the actionsWithArray: method does the exact same thing as I wrote (compositing a action tree), it just hides it from the user. Thanks!

Posted 3 months ago #

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