Rotating Turrets: How To Make A Simple iPhone Game with Cocos2D 2.X Part 2

[rwenderlich]

This is the official thread to discuss the following blog post: Rotating Turrets: How To Make A Simple iPhone Game with Cocos2D 2.X Part 2

[tic]

Hi

I am confused at how the CCSequence for _nextProjectile will not execute until the CCSequence for _player has finished.
Could you clarify?

Thanks

[urth]

Thanks for this tutorial.

There is a couple of bugs that I found.

1. If you shoot a projectile with the offset.x <= 0 the next touches do not produce any projectiles since _nextProjectile is not nil. So the if statement should be:

Code: Select all

    // Bail out if you are shooting down or backwards
    if (offset.x <= 0)
    {
        [_nextProjectile release];
        _nextProjectile = nil;
       
        return;
    }


2. The pew pew sound is produced when the projectile is defined not when it is added to the layer. If you shoot a shot in the vertically up then another vertically down you hear the sound before the projectile is fired from the canon. A better placement would be when adding the projectile to the layer:

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         [self addChild:_nextProjectile];
         [_projectiles addObject:_nextProjectile];
         [[SimpleAudioEngine sharedEngine] playEffect:@"pew-pew-lei.caf"];


Best regards,

Hussam Kazah

[akram]

Hai,

Actually this tutorial going for landscape mode for rotating firing Turrets , Once i have designed for portrait mode for iphone then how can i run the touch handles please clarify me once. Send sample code if u have ...

Thanks

[Erick Beard]

I am trying to modify the code so that I can position a rotating turret at the bottom center of the screen. The positioning went fine for the sprite and the starting position of the bullets, but I am having trouble firing to the left side of the screen. I commented out the section of code for bailing out if shooting down or backwards, unfortunately the turret fires down and to the right when I attempt to shoot on the left side of the screen. I understand this involves the positional coordinates, but I don't know how to fix the problem. If I find a solution before I can get any assistance, then I will post it here.

Code: Select all

- (void)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
   
    if (_nextProjectile != nil) return;
   
    // Choose one of the touches to work with
    UITouch *touch = [touches anyObject];
    CGPoint location = [self convertTouchToNodeSpace:touch];
   
    // Set up initial location of projectile
    CGSize winSize = [[CCDirector sharedDirector] winSize];
    _nextProjectile = [[CCSprite spriteWithFile:@"projectile2.png"] retain];
    _nextProjectile.position = ccp(winSize.width/2, 20);
   
    // Determine offset of location to projectile
    CGPoint offset = ccpSub(location, _nextProjectile.position);
   
    // Bail out if you are shooting down or backwards
    //if (offset.x <= 0) return;
   
    // Determine where you wish to shoot the projectile to
    int realX = winSize.width + (_nextProjectile.contentSize.width/2);
    float ratio = (float) offset.y / (float) offset.x;
    int realY = (realX * ratio) + _nextProjectile.position.y;
    CGPoint realDest = ccp(realX, realY);
   
    // Determine the length of how far you're shooting
    int offRealX = realX - _nextProjectile.position.x;
    int offRealY = realY - _nextProjectile.position.y;
    float length = sqrtf((offRealX*offRealX)+(offRealY*offRealY));
    float velocity = 480/1; // 480pixels/1sec
    float realMoveDuration = length/velocity;
   
    // Determine angle to face
    float angleRadians = atanf((float)offRealY / (float)offRealX);
    float angleDegrees = CC_RADIANS_TO_DEGREES(angleRadians);
    float cocosAngle = -1 * angleDegrees;
    float rotateDegreesPerSecond = 180 / 0.5; // Would take 0.5 seconds to rotate 180 degrees, or half a circle
    float degreesDiff = _player.rotation - cocosAngle;
    float rotateDuration = fabs(degreesDiff / rotateDegreesPerSecond);
    [_player runAction:
     [CCSequence actions:
      [CCRotateTo actionWithDuration:rotateDuration angle:cocosAngle],
      [CCCallBlock actionWithBlock:^{
         // OK to add now - rotation is finished!
         [self addChild:_nextProjectile];
         [_projectiles addObject:_nextProjectile];
         
         // Release
         [_nextProjectile release];
         _nextProjectile = nil;
     }],
      nil]];
   
    // Move projectile to actual endpoint
    [_nextProjectile runAction:
     [CCSequence actions:
      [CCMoveTo actionWithDuration:realMoveDuration position:realDest],
      [CCCallBlockN actionWithBlock:^(CCNode *node) {
         [_projectiles removeObject:node];
         [node removeFromParentAndCleanup:YES];
    }],
      nil]];
   
    _nextProjectile.tag = 2;
   
    [[SimpleAudioEngine sharedEngine] playEffect:@"pew-pew-lei.caf"];
}