My iPhone Game Tutorials for Beginners

[Silverwind]

Oh yeah, I don't think I mentioned it but I finally got around to watching the first of your iPhone tutorials a few weeks back. It's really good Gan. I actually understood it without popping a lobe, hehe...

[Gan]

Awesome. Hopefully soon you'll be making your own great apps.


-Gan

[breshi]

I have an interesting problem.
I have used your fantastic Game making structure as my base and have written what I think is a pretty good game. Everything was perfect until I upgraded to OS4 - now the game runs extremely slow.
I can easily fix this within the code but then when the game runs on earlier OS versions it will run extremely fast.
Has any one else run across this problem?

I would have thought that since all my other games (on my iPhone) run well on all OS versions the problem lies with your base Game Structure. I can do an overall fix and check to see what version of the OS is being used and slow down/speed up the game accordingly but why don't other games not written for OS4 have this problem?

[Gan]

It's probably my game structure. I made the structure before os 4 and while I was a beginner.
Currently I use a new structure that's similar to this one. Though it's quite a bit more advanced and uses OpenGL and a reliable thread loop for logic.
If you want I can make my latest one a bit more beginner friendly and post it up. Because it uses OpenGl you can have a ton more objects on screen.
If you don't want to use the new template I have code to get the os number. That way you don't need to change anything.


-Gan

[breshi]

That would be fantastic!
Would it be a hard thing to modify the old structure, i'd hate to have to rewrite my entire game?
Keep up the great work!!!

[I-NEED-HELP]

Thanks for your help with opening/saving files!

But what if the app is running for the first time... would you create a new file? But then how would you tell whether the app was running for the first time or not? Or if you could test whether or not the file already exists? How to tell whether or not a file exists?

Thanks in advance.

[Gan]

Here's the code to detect the current OS:

Code: [Select]

if ([[[UIDevice currentDevice] systemVersion] floatValue] < 4.0) {
//Less then 4.0
} else {
//4.0 or greater
}

To check if your file exists just load it as normal and do this:

Code: [Select]

if (testFile == nil) {
//File doesn't exist
}

I will see about converting it but still pretty busy.


-Gan

[I-NEED-HELP]

I tried with the file stuff for highscores, but when my program gets to the part where it's supposed to check highscores and update the file, it crashes. Any help?

Code: [Select]

            int score = loopCounter;
            if (!gottenScore) {
                  NSMutableArray* highscore = [NSMutableArray new];
                  highscore = [self openFileInDocs:@"Highscore.txt"];
                  if (highscore != nil) {
                        if (score > [[highscore objectAtIndex:0] intValue]) {
                              [highscore replaceObjectAtIndex:0 withObject:[NSNumber numberWithInt:score]];
                              gotHighscore = TRUE;
                        }
                        [self saveFileInDocs:@"Highscore.txt" object:highscore];
                  }
                  else {
                        [highscore addObject:[NSNumber numberWithInt:score]];
                        [self saveFileInDocs:@"Highscore.txt" object:highscore];
                  }
                  gottenScore = TRUE;
                  
                  [self drawString:context translate:CGPointMake(0, 0) text:[NSString stringWithFormat:[highscore objectAtIndex:0]] point:CGPointMake(0, screenDimensions.y-130) rotation:0 font:@"Arial" color:color size:20];
                  if (gotHighscore) {
                        [self drawString:context translate:CGPointMake(0, 0) text:@"HIGHSCORE!" point:CGPointMake(70, screenDimensions.y-80) rotation:0 font:@"Arial" color:color size:20];
                  }
            } 

[I-NEED-HELP]

I was wondering how to resize a sprite. Your drawing methods seem to leave the sprite dimensions as they were, but I would like to be able to change them, e.g. make a sprite from a file that is 20x20 pixels but show it on the screen as 40x40 pixels. How do you do this?

Thanks in advance.

[I-NEED-HELP]

Do you know of a graphic design program better than pixen? Pixen is to blocky for what i want to be creating.

Sorry this is really late, your question might have already been answered, but I use GIMP. Gnu Image Manipulation Program. It's free, easy to use, and I use it for all my sprites in games. It has tons of awesome tools too, very nice software. You can save as tons of different image formats, even as ASCII art! Try it.

[I-NEED-HELP]

How to you use OpenGL to draw 2d sprites? Can you post a tutorial? Or update the iPhone Game Template code so that is uses OpenGL ES instead of CoreGraphics? I'm making a sprite intensive game that requires very fast update speeds.

Thanks in advance.

[breshi]

Yes, that would be a great help to find out how to use openGL for sprites. With the update to OS4 I have to rewrite my game to speed it up - not sure how.

[Gan]

Here's one of my old opengl templates. It has most of what you need to get the job done but it's a mess.
If I had more than 5 minutes I could clean it up.

http://web.mac.com/avisaria/OpenGL%20Template.zip


-Gan

[I-NEED-HELP]

THANK YOU!  

[Gan]

I'm remaking the template. This latest will completely blow all previous templates out of the water.
I'm making it so that you can build all menus in interface builder while having the game view a little separate for maximum speed in an easy to use OpenGl ES view.
This also allows use of professional looking transitions.


-Gan