Reliabit

Put in changes to make Sea Assault and Ant Planet work better with multitasking. So, the games should pause in the background properly. If OpenGL is used in the background, then the game content might have to be reloaded into the context when you bring the app to the foreground -- the OS will terminate the app if it finds out your using OpenGL. Since I enabled multisampling, the programs are linked against the iOS 4 sdk. Just pause in the background. Same code for handling incoming calls too while playing.

The second generation iPod and the 3G phone do not have multitasking in iOS 4. On that hardware its like the old iOS 3 behavior.

Submitted the fixes to iTunes Connect.

Also, I notice if you have developer logging turned on, the logging can cause animation hiccups while playing. I figure most people will not have that enabled.

Sort of a pain to debug the iPod with iOS 4.0. For some reason, if you type in your wireless network password it will not accept the shift key! All lower case! But looks like iOS 4.01 handles this properly. iTunes currently does not update iOS to 4.01 for iPods -- think the main purpose of this was to fix the phone reliability issues. The only way around it was to use the iPhone Configuration Utility with network settings.

Today, Sea Assault has become multisampled ! That is, the game has better anti aliased edges.

On a typical pc, this would be fairly easy. You just enable multisample with glEnable. But on the iDevice, you have to set up an additional frame buffer object and use the OpenGL ES extension GL_APPLE_framebuffer_multisample. 

There are some annoying issues in both Sea Assault and Ant Planet that can be remedied by multisampling. In Sea Assault, the helicopter blades appeared too pixelated and the edges of the landing pad appeared jagged. In Ant Planet, the ant legs appear pixelated too.

All devices running iOS 4 and with newer hardware than the 3G should support multisampling. As far as iPod is concerned, that would be the high end iPod 3rd generation too. Unfortunately, this feature is not implemented in iOS 3 on all hardware. With the change, I made sure the games will still be compatible with older versions of iOS.

Here are some screen shots. I put red arrows in the picture to illustrate the improvement.

No multisampling:

Here are some screenshots with multisampling turned on and samples set to 4 :

I made multisample a preference option too. Surprisingly, its still quite fast on the 3GS iPhone and iPod Touch 3rd generation.

So, should be a Sea Assault update soon after some more testing. And then Ant Planet....

Downloaded the newest official XCode tools. The new tools include iPad support. I tend to avoid beta releases of developer tools.

Seems real easy to convert the app to a universal app -- an app that runs on iPod/iPhone/iPad. Basically, control click on your target and then update it for iPad. XCode creates a different xib file for each device and changes project settings automatically. It does give an option to create separate binaries. Now you can create completely different layouts with interface builder for each device which is sort of cool. The app must run on os 3.0 or greater.

There are some info plist settings that need to be added. For instance, supported interface orientations. All orientations need to be supported on iPad and I'll have to review that.  There are different icons that can be added beyond the typical 57x57 icon on the iPad. After converting my latest app I've been working on to universal, I created one of the default applications that XCode creates and compared it.

Some minor things I've run into are assuming the height and width of the viewport can be a problem. Its different dimensions on the iPad. Also, there is much more real estate for the cocoa touch interface that presents the game. Lots of space to use. Icon sizes can be a problem too -- too big or small.

Been busy enabling my toolkit to work with OpenGL ES 2. The goal is, if the program detects OpenGL ES 2, then viola you have shaders. I figure many a developer are going down this path. Its a good bridge to iPad and back to the Mac -- especially iPad because the hardware from the get go is going to be ES 2 enabled.

I've been down this road with OpenGL 2.x but going from ES 1 to ES 2 is a much more rocky proposition. Yet, its more rewarding, if you can pull it off. It feels like going from OpenGL 1.x to OpenGL 3.x.

The two difficult parts seem to be replacing the matrix stack operations ( glPushMatrix etc. ) and then integrating vbo with the shaders. uniforms are pretty obvious. Though, attributes need to be set before the program link.

The matrix stuff is straight forward unless you run into a math issue. Math is unforgiving. But its a good review. In the long run, it would appear spinning your own matrix stack operations might lead to some nice optimizations. One thing to look out for is all the man pages are column major when they show matricies. So, you have to do a transpose, if you pass your 4x4 matrix to OpenGL. eg. glLoadMatrixf ( matrix[0] ) ...

The curve with the vbo stuff is glNormalPointer, glVertexPointer and glTexCoordPointer go away and are replaced with glVertexAttribPointer. That is different from OpenGL 2.x.  Also, I was not packing my structure right under gcc which created all sorts of fun with attribute buffer offsets. gcc does not recognize pragma pack apparently.

I like to standardize on uniform names. In the long run, I'll build up a library of shaders. So, picking consistent names is an action item early on. Another interesting thing is that shaders can be made binary. A rule of  thumb on shaders is to limit setting uniforms as much as possible. So, I plan not to generalize my shaders. That is hardcode the colors and as much stuff into shaders as possible -- or just set the uniform once right after the compile. This can be a big issue on the Mac because you want to avoid the cpu talking to card as much as possible.

Not sure OpenGL Shader Builder in the development tools works consistently with essl ( the OpenGL ES equivalent to OpenGL glsl ). Though, I hear Apple is doing a major upgrade to OpenGL 3.x. I bet this will make things work better with OpenGL ES 2 -- Mac desktop simulator and tools. Maybe the next  OpenGL Shader Builder will work. Shader tools on the Mac have always been lacking. No Render Monkey etc. Maybe with iPhone so prominent its time for people to get serious about shader related tools on the Mac.

Looks like you cannot have floating point fbos according to books I've been reading on ES 2. But you can have render to depth which is going to be important for shadowmaps. Since there is no floating point fbo, then ping pongs are going to be limited and you'll get aliasing.

Another difference appears that in ES 2 you have to use shaders. Where as, in Opengl 2.x you could switch between the old fixed pipeline stuff and the shader stuff. So, fixed pipeline really is gone in ES 2.

Much more to do .... all disclaimers apply. Fortunately, there are many similarities between OpenGL ES 2 and plain old OpenGL 2.x.

Not quite enough for any screenshots yet. But good progress so far. Think the most difficult goals in this process have been achieved.

Today, I submitted the next Sea Assault update. Its rather close to the last update but I want to make sure the version tested with iPad simulator is released. 

I spruced up explosions more and added more sparks to the game. When the helicopter and turrets fire they emit some smoke too. Fixed some other depth kinks with particles that were present in the last version.

To help with ground targets, I added a small red targeting line. This makes it easier to hit ground targets or at least to know where the shots are going to hit when you fire at the ground.

There is a transition animated effect going into and out of game view which is a nice use of Cocoa Touch -- similar to the recent Ant Planet change.

I notice that clicking on links to the iTunes store will also bring up a web page. This is nice because now everyone on the web can see what is available on the store. It use to work only with the iTunes program.

I've been working this weekend on getting all three games working on the iPad simulator. I can't give much detail about the specifics because there is beta software developer restrictions. But I will say that the games will work on the iPad. Sea Assault and Ant Planet will have one update to correct some technical issues -- I've already done the fixes. These updates will ensure the iphone/ipod games work on the iPad. They will not add any specific iPad functionality. As Apple demonstrated in public, you will be able to launch the iPhone/iPod based game and there will be a 2x button to enlarge the game's view.

Before the previously described iPad oriented updates, there is a Sea Assault update that fixes some minor issues with the last release and uses point sprites rather than quads for particles.

So, there are three updates in the next 60 days coming down the pipe. I recall from when iPone OS 3.0 came out, there was quite a jam to get updates out. I want to get ahead of the curve this time. I also remember from the 3.0 release, that the store put a check box up to verify that you have tested it on 3.0 -- I wonder if that will happen with iPad too.

Fortunately, I have another disk partition to install the beta software on. I see people getting tripped up like last time when they overwrite their tools with beta software and find out they cannot publish to the store!