Cocos2D Book Update: Progress Report

On May 29, 2011, in book, cocos2d, by Steffen Itterheim

It’s coming along great!

I completed the revisions on Chapter 1 through 5. The entire source code is now updated to use cocos2d-iphone v1.0.0 rc2. To make future code updates easier I also wrote a script that allows me to copy a newer cocos2d version to all projects, which essentially does Steps 1 & 2 described in the Updating Cocos2D in an Existing Project tutorial.

Most Notable Changes

Chapter 4 now includes a description of Glyph Designer for making Bitmap Fonts, and only mentions Hiero on the side. Glyph Designer is the better tool hands down.

Chapter 5 has seen a revision of the paragraph that explains subclassing from NSObject. I think I went too far off course here and subclassing from CCNode will make a lot of things easier while still giving the same benefits regarding class composition.

In Chapter 6 I decided to replace all descriptions of Zwoptex with TexturePacker as the preferred tool for making texture atlases.

For a while it looked like Zwoptex and TexturePacker would be competing on the same level. But recently Andreas Löw (TexturePacker & PhysicsEditor) made the move to work full-time on his tools, whereas Robert Payne is busy with a full-time job. I think the prospects are looking much better for TexturePacker now, and it is already leading in terms of features and update frequency.

That’s it for now.

Linkvent Calendar, Day 3: MVC with Cocos2D

On December 3, 2010, in Cocos2D Linkvent Calendar, by Steffen Itterheim

Today’s link is about the Model-View-Controller (MVC) design pattern and how to implement it in Cocos2D. Bartek Wilczyński from Poland has written a two-part tutorial about how to implement this design pattern, and explains why this is a good design choice:

How to implement MVC pattern in Cocos2D game – Part 1
How to implement MVC pattern in Cocos2D game – Part 2

While I was reading that, I remembered that Jeremy Flores had created a github repository with his implementation of a MVC pattern in Cocos2D. He dubbed his project Cocos2D-MNC, as in Model-Node-Controller. The code is published under the MIT license.

The MVC pattern is somewhat similar to a game object component system that I described here. For both systems, the general idea is not to subclass CCSprite and put your game logic in there. CCSprite already is a complete visual representation class for your player, enemy, and what not. But in some cases, you need more than one sprite, or a combination of a sprite and particle effects. Once you get there, it’s much better to have a CCNode containing (aggregating) all the visual elements of your game object, while handling all the game logic of that object and updating the visual elements. The CCNode becomes the controller, controlling the views. As the views (sprites, effects, GL drawings, etc.) move on screen, the controller node polls the visual nodes for state information and runs the game logic code, which in turn may update the views.

In very simple terms, this is my pragmatic approach of the MVC pattern that also works quite well. It’s definitely already a big leap forward compared to extensively subclassing the CCSprite class. If you notice that you’re doing that a lot, you should do yourself a favor and read up on the MVC design pattern.

Add your link to the Cocos2D Linkvent Calendar

Do you have something to share with the Cocos2D community? I haven’t received enough submissions to fill all the days until Xmas, although I do have enough links to post one each day, I’d rather post a link to your website or blog post.

cocos2d Book, Chapter 6: Spritesheets & Zwoptex

On July 30, 2010, in Announcements, book, cocos2d, by Steffen Itterheim

Chapter 6 – Spritesheets and Zwoptex

In this chapter the focus will be on Spritesheets (Texture Atlas), what they are and when, where and why to use them. Of course a chapter about Spritesheets wouldn’t be complete without introducing the Zwoptex tool. The graphics added in this chapter will then be used for the game created in the following chapter.

The chapter will be submitted on Friday, August 6th.

Anything about Spritesheets you always wanted to know?

Just let me know. I’ll be researching what kind of issues people were and are having regarding Spritesheets. I want to make sure that they are all covered in the book.

Please leave a comment or write me an email.

Summary of working on Chapter 5 – Game Building Blocks

I finally found a better title for the chapter. A big part is about working with Scenes and Layers. A LoadingScene class is implemented to avoid the memory overlap when transitioning between two scenes. Layers are used to modify the game objects seperately from the static UI. I explain how to use targeted touch handlers to handle touch input for each individual layer, either swallowing touches or not.

The issue of whether to subclass CCSprite or not is discussed and an example is given how to create game objects using composition and without subclassing from CCNode and how that changes touch input and scheduling.

At the end the remaining specialized CCNode classes such as CCProgressTimer, CCParallaxNode and the CCRibbon class with the CCMotionStreak are given a treatment.

As you can see from the pictures, I’m also making good progress at becoming a great pixel artist. Only I have a looooooong way ahead of me still. But I admit, the little I know about art and how much less I’ve practiced it, I’m pretty happy about the results and having fun with it. The cool aspect of it is that this should be instructive art. It doesn’t have to be good. So I just go ahead and do it and tend to be positively surprised by the results. I’ll probably touch this subject in the next chapter about Spritesheets: doing your own art. It’s better than nothing, it’s still creative work even if it may be ugly to others, and it’s a lot more satisfying to do everything yourself, even if it takes a bit longer and doesn’t look as good. At least it’s all yours, you’re having fun, and learn something along the way. And you can always find an artist sometime later who will just draw over your existing images or who replaces your fart sound effects with something more appropriate.

Btw, if you’re looking for a decent and free image editing program for the Mac, I’ve been using Seashore for about a year now and I’m pretty happy with it.