CCMoveTo doesn't get the updated player postition…(iphone,cocos2d)
I’m adding an enemy like this:
-(void)addEnemy {
if ([spawnedEnemies count] < 25) {
CCSprite* sprite = [CCSprite spriteWithFile:@"white.png"];
float randomX = arc4random() % 480;
float randomY = arc4random() % 320;
sprite.position = ccp(randomX,randomY);
[spawnedEnemies addObject:sprite];
[self addChild:sprite];
[sprite runAction:[CCMoveTo actionWithDuration:5 position:player.position]];
} }
but if my player moves the sprite still moves to the last player position…
because of that i tried this in my tick:
-(void)tick:(ccTime)delta {
for (CCSprite *sp in spawnedEnemies) { [sp stopAllActions]; [sp runAction:[CCMoveTo actionWithDuration:5
position:player.position]];
} }
but the enemies will only move if i stop moving (there just moving reallllllllyyyyyyyyy slow because every time i move it calls [sp stopAllActions]
What should I do now?
EDIT:*EDIT:*EDIT:*EDIT:*EDIT:*EDIT:*EDIT:*EDIT:*EDIT:
Now I’m doing this and the enemies are moving to the player even if the player is moving
but there’s a problem: the nearer the enemy (is to the player) the slower they are moving…
How to solve this?
//function to apply a velocity to a position with delta
static CGPoint applyVelocity(CGPoint velocity, CGPoint position, float delta){
return CGPointMake(position.x + velocity.x * delta, position.y + velocity.y * delta);
}
-(void)tick:(ccTime)delta {
for (CCSprite *sp in spawnedEnemies) {
CGPoint m = ccpSub(player.position, sp.position);
sp.position = applyVelocity(m, sp.position, 1.0/60.0f);
}
}
I have four ideas:
-
Schedule a new update selector with a lower frequency and move the enemies in that method:
[self schedule:@selector(moveEnemies) interval:0.1];
-
Only move the enemies when the player.position changes, maybe in your
ccTouchesMoved
-method. -
Instead of using CCActions, set the position of the sprite directly, you need to do some vector-computations.
-
Use a physics-engine like Box2D (included in Cocos2D SDK). Then you can simply apply a force to each enemy to the direction of the player in each step.
EDIT:
In order to move the enemies with constant velocity, normalize the velocity vector m:
m = ccpMult(ccpNormalize(m), kSpeed);
kSpeed is a constant float value to adjust the speed.
Hope that helps…