Just in case you are unfamiliar with a custom url scheme – this refers to binding your app to a specific url scheme such as twitter:// which when used will execute the related app on the user’s iOS device.  What’s really cool is that you can attach custom parameters depending on the app for example:
twitter://post?message=visit%20maniacdev.com

You simply load the url, and the app opens.. it’s that easy.

There are literally hundreds and I was reminded about a site just the other day by Alex Curylo that has grown leaps and bounds since I last looked at it, and it lists many of these URL schemes.

That site is handleOpenUrl.com and you can search for specific applications or even for specific types of applications, for example here’s what comes up when I search for Twitter apps:
?

What’s really cool is that if you click on one of the selections it gives examples on how to use a specific app’s url scheme like this:

If you would like to know how to add a URL scheme into your own app iPhone developer tips has this great tutorial:
Launching Your Own App Via A Custom Url Scheme

If you liked this, please share it!

[Via: Alex Curylo]

©2010 iPhone iOS 4 iPad SDK Development Tutorials, Programming Tips, News. All Rights Reserved.

I’ve been asked since then when I would come out with the tutorial.   I was finally able to get around to completing the source file, and I’ve added line by line (well pretty close) comments in plain english to make it easier to follow.

The above video utilizes the exact source code from this tutorial running in the iPhone simulator.

Following the suggestions of a friend of mine who is just starting to learn this I’ve used as few methods as possible, and made extensive use of autorelease objects to make the flow easier to follow for beginners.

The tutorial features:

• Loading/Placing Images
• Animation
• Touch Events
• Text
• Sound Effects
• Background Music
• Buttons
• Resetting The Game

Coming up next week I will be posting a more comprehensive tutorial, but I am posting the source code now.  If you look through this code and the comments you should be able to grasp what is going on, and I hope that the upcoming tutorial will fill in the gaps. Be sure to come back next week when the full tutorial is posted!

I recreated this from scratch using Sparrow Framework and Objective-C because in my findings it was easiest to follow for a beginner looking to create an action game.

Things could change a little as I haven’t really looked through it myself.. just quickly coded it and wrote line by line comments. If you open it up, and are wondering which files to look at to understand things go to the Game.h and Game.m files.. the app delegate files were created automatically with the Sparrow project and I didn’t comment those.

Update! I have modified the project to remove an error that occurred on some systems due to a recursive search being done in the project for already included files.  Please re-download if you encountered this problem.

You can download the source with music/sound effects here:
BalloonGameTutorial

Graphics are included so the example will run but are slightly different because I am using graphics similar to those in the video in my own game.

As far as licensing goes feel free to use this in your own apps, and if you do send me a message or post a comment about it, and I’ll mention it on this site. You may not use any portion of this project in your own tutorials, books, etc. (and definitely don’t submit it to a site buying tutorials.. you know who you are!) without permission.

Please be sure to check back next week when the entire tutorial is posted which will give you a much better idea of how to extend/use this source code and utilize the Sparrow Framework.

If you have any questions as to why I did something or have any suggestions for the tutorial then please post them below — it will help to make the final tutorial better.

Also, if you could share this post that would be great too and help motivate me to make more!

©2010 iPhone iOS 4 iPad SDK Development Tutorials, Programming Tips, News. All Rights Reserved.

I’ve always found it difficult to follow along with most of the tutorials on the different art sites, and it doesn’t help that Photoshop updates so often, and it seems with each update hundreds of new buttons are added.  It’s really something you need to see done not simply shown in a series of screenshots.

That being said I’ve found some excellent tutorial screencasts made for iPhone developers by an iPhone developer.

The tutorials are from an ongoing  series by Mike Berg, and they currently feature:

1. App Icon Design and Resolution Independence – which includes a template to quickly start your icon, how to use vector layers, creating icons of the right sizes, smart layers, and how to use the preview window when working on small icons.
   
2. How and when to use clipping masks – how to place a photo within a special border, texturing a chess board, adding reflections, adding art to a shaped and angled surface (in this case a billboard), and creating sillhouettes for your vector art.

There are some really cool things going on in these tutorials, and it is nice to see how things are really done.  If you’re trying to get better at Photoshop I highly suggest you check these out.  I really hope Mike keeps up with the series!

Thanks for reading, if you liked this then please share it!

©2010 iPhone iOS 4 iPad SDK Development Tutorials, Programming Tips, News. All Rights Reserved.

Thankfully a fix has been added, and an update to Cocos2D has been released (0.99.4 RC2).

[Source: Cocos2D Blog]

©2010 iPhone iOS 4 iPad SDK Development Tutorials, Programming Tips, News. All Rights Reserved.

There are a couple of great open source tools which can greatly help in creating platformers on the iPhone and iPad.  Two of them are the Cocos2D game engine, and the Tiled map editor which are designed to work together.

Ray Wenderlich has posted a couple of excellent tutorials on creating a game using Cocos2D and tiled these tutorials go through the process of building a game from the ground up, and explain everything from laying out the tiles, and creating the game in a straightforward manner so if you are interested in creating an iPhone or iPad platform game check them out.

Tutorial #1: Creating The Project, Making The Map and Adding It To The Game
Tutorial #2: Collisions, Modifying The Map Dynamically

Please subscribe to our RSS feed for more iPhone and iPad development tutorials and programming tips.

©2010 iPhone iOS 4 iPad SDK Development Tutorials, Programming Tips, News. All Rights Reserved.

Oliver Drobnik has created an excellent example of using Box2D with the UIKit.  This is a great example for those who are not familiar with, or don’t have any interest in using Cocos 2D.

[Source: Dr. Touch]

©2010 iPhone iOS 4 iPad SDK Development Tutorials, Programming Tips, News. All Rights Reserved.

A couple of new tutorials have been created featuring techniques for creating more accurate collisions methods.

The first tutorial is from 71 Squared on Collision Detection Methods which has a some nice straightforward functions written in C that you can drop into your code for Circle to Rectangle, and Circle to Circle collisions.

The second tutorial is from Ray Wenderlich and goes through the process of how to use sprites in Cocos2D and how to get extremely accurate vertex based collisions using box2D in How To Use Box2D For Just Collision Detection In Cocos2D iPhone.

[Source: 71 Squared, Ray Wenderlich]

©2010 iPhone iOS 4 iPad SDK Development Tutorials, Programming Tips, News. All Rights Reserved.

It’s a major hassle to do this by hand, and for me personally it’s things like this that hold me back from doing things, or sometimes taking an easier way out (like using box collisions or spherical collisions just so I don’t have to do this), but it’s a fairly quick process selecting things graphically with this program

Fortunately Johannes Fahrenkrug has created a very nice time saving tool for getting these vertex locations, see this video of it in action:

As you can see it can even print out formats specifically for Box2D and Chipmunk which is great for Cocos2D fans.

You can download the source here on git: VertexHelper with a full Xcode project for easy compilation on your Mac (sorry windows users).

[Source: Springenwerk Blog by Johannes Fahrenkrug]

©2010 iPhone iOS 4 iPad SDK Development Tutorials, Programming Tips, News. All Rights Reserved.

The tutorials are from Ray Wenderlich, and the first thing that you will want to do is check out Intro to Box2D with Cocos2D Tutorial: Bouncing Balls.  In this tutorial you’ll learn how to create a Box2D project, and how to add physical characteristics to 3D objects with Box2D.

Next you’ll want to check out How To Create A Simple Breakout Game with Box2D and Cocos2D Tutorial: Part 1/2, in this tutorial you’ll use what you learned in the first tutorial and in addition turn the ball into an ever bouncing ball, and add a paddle that you can move across the screen along with how to set up collisions between the two.

Finally, go through How To Create A Simple Breakout Game with Box2D and Cocos2D Tutorial: Part 2/2, and you’ll learn how to place blocks for the ball to hit, and how to set up collisions between the objects and finally an end of game screen.

[Source: Ray Wenderlich]

©2010 iPhone iOS 4 iPad SDK Development Tutorials, Programming Tips, News. All Rights Reserved.

Coming from a background in web programming and databases, my first experience with game programming was a surprisingly pleasant one. While “Knife Toss” isn’t exactly “Call of Duty: Modern Warfare,” I was still initially concerned that I would have no idea how to even begin working on a video game. But in the end things became very intuitive and I was able to use my prior software engineering skills to adapt quickly to the environment of game development. That is not to say there wasn’t a learning curve throughout the process.

Knife Toss Game Trailer:

Understanding Game Objects

The biggest obstacle for me was getting a grasp on game objects in Unity3d. A novice game developer might find this task extremely simple. But I had never worked with 3D graphics, textures, materials, colliders, meshes or anything related to modeling or gaming. Once I was able to figure out how all of that worked, and how to wire up the code to it, things became comprehensible. It was challenging enough to make me think, but not so hard that it would take the fun out of it.

Coding With C#

We did all of our coding in in Mono – A Open Source implementation of C#. I had never worked with C# previously, but this wasn’t an issue at all due to my past experience with Java. Unity also allows code to be written in a Unity version of Javascript, which happens to be what all their documentation is shown with. This was an issue a few times when the javascript implementation of a Unity Engine function was actually quite different then what was needed with C#. Something I found interesting was that it seems most people in the Unity community use C#. Although little Object Oriented Programming was used in “Knife Toss,” I see it as the obvious advantage of C# over Javascript. (Side Note: The non-iPhone version of Unity3d allows for a third scripting language based on Python called “Boo”. If they ever bring this to Unity iPhone I’m going to switch and never look back) The programming process overall was pretty straight forward. We did have big issues throughout the process, but they were seldom due to coding.

Handling Textures

Textures are what killed us. We got to the final stages of finishing the game when I discovered that we were using up huge amounts of RAM. I had never thought to check before because the game always ran fine on my device. It turns out it did not run fine on other devices, specifically the first generation iPod Touch and the original iPhone. We ended up having to redo all the texture sprites and consolidate them down to two 1028×1028 sheets. This began the most frustrating week and a half of the whole development process for me. I had to redo all of our menus, GUI elements and on screen displays by readjusting all of their coordinates. Finally we got everything back in place and as a result we cut our RAM usage by almost 20MB.

Submitting To The Store

Now that our game was optimized and working well on all compatible devices, we were ready to put on the finishing touches and begin intensive testing. When the game finally was complete, I carefully went through Apple’s process to submit to the App Store. This process is not as difficult as it seems when you first glance over their set of procedures. Our first game was finally submitted and it felt great. I still wasn’t fully satisfied though. I had read so many horror stories about the App Store submission process that in the back of my mind, I actually was expecting to be rejected the first time around. I was wrong. The game was accepted a few days later. After working through a bit of a mix-up with the contracts our game was finally for sale across the world.

Some Tips For First Time Developers

My first experience with game development was an excellent learning process. Now that our team has the first game out of the way, look for us to begin pumping out games left and right. Here is a list of tips I have for any first time game developer, specifically using Unity3d for iPhone:

• Go through the tutorials that are provided for you. I read through them, started them, but then became to impatient to finish. Had I actually finished, I would have saved a lot of time instead of having to go back and figure out how to do certain things which actually were covered very well in the tutorials.
• Plan out your game as detailed as possible before beginning. If you are working with a team, make sure this idea is stressed. What may seem like a minor change or addition to someone who didn’t program the game, may be very difficult or may require completely redoing certain aspects of the game on the programming side. This also will prevent “band-aid programming.”
• Use texture atlases and use as few sheets as possible.
• If possible, do all testing on a first generation device. If it works on that it’ll work on the faster devices.
• Use the Unity Remote. It’ll save you tons of time.
• Create a copy or a pseudo “version” of your project at least once a day. Sometimes things will get messed up and you won’t be able to figure out what you changed to cause it. Always have something to fall back to.
• Use Object Oriented Programming often. Nothing is more irritating then searching through your huge, single class file to find one of the hundreds of variables that have been accumulated.
• Use the profiler and Apple’s “Instruments” often to check your games performance and resource usage.
• Read through the documentation in Unity. Especially the optimization sections. It contains plenty of useful and sometimes absolutely necessary tips to make your game ready for sale.
• Avoid allocating memory during game play if possible.
• Use the Unity forums. For the most part everyone is very helpful and they are not rude to beginners as long as you aren’t asking questions that are readily available in the documentation. Also, the search feature is your friend.

I’d love to help out the best I can if anyone is looking for help getting started. Feel free to email me at pat@crawlspacegames.com or just post to the Unity forum. I always reply to post if I think I can help out.

You can also check out Pat’s website Crawl Space Games where his gaming creations are featured.

©2010 iPhone iOS 4 iPad SDK Development Tutorials, Programming Tips, News. All Rights Reserved.