Book Image

Creating Games with cocos2d for iPhone 2

By : Paul Nygard
Book Image

Creating Games with cocos2d for iPhone 2

By: Paul Nygard

Overview of this book

Cocos2d for iPhone is a simple (but powerful) 2D framework that makes it easy to create games for the iPhone. There are thousands of games in the App Store already using cocos2d. Game development has never been this approachable and easy to get started. "Creating Games with cocos2d for iPhone 2" takes you through the entire process of designing and building nine complete games for the iPhone, iPod Touch, or iPad using cocos2d 2.0. The projects start simply and gradually increase in complexity, building on the lessons learned in previous chapters. Good design practices are emphasized throughout. From a simple match game to an endless runner, you will learn how to build a wide variety of game styles. You will learn how to implement animation, actions, create "artificial randomness", use the Box2D physics engine, create tile maps, and even use Bluetooth to play between two devices. "Creating games with cocos2d for iPhone 2" will take your game building skills to the next level.
Table of Contents (16 chapters)
Creating Games with cocos2d for iPhone 2
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Power-ups, good and bad


The idea of power-ups is core to the modern brick breaking experience. For our game, we will be implementing three types of power-ups: paddle expanding, paddle contracting, and multiball. As we just saw, when a brick is destroyed another method gets called to handle the power-ups.

Filename: BRPlayfieldLayer.mm

-(void) checkForRandomPowerupFromPosition:(CGPoint)brickPos {
    NSInteger rnd = arc4random() % 100;
    
    if (rnd < 25) {  // 25 % CHANCE
        [self buildPowerupAtPosition:brickPos];
    }
}

In this method we randomize a number. If it is below 25 percent, we call another method to actually build a power-up. It is important to point out that in the spriteDestroy method, we must call this method before we removeFromParentAndCleanup because we will need to use the position of the brick that is being destroyed here. This allows the power-up to drop from "inside" the brick that was just destroyed.

As we follow this code path, we now reach the point...