mrdatabase - Page 2 - Developer IT

Using XCode and instruments to improve iPhone app performance

- by MrDatabase

I've been experimenting with Instruments off and on for a while and and I still can't do the following (with any sensible results): determine or estimate the average runtime of a function that's called many times. For example if I'm driving my gameLoop at 60 Hz with a CADisplayLink I'd like to see how long the loop takes to run on average... 10 ms? 30 ms etc. I've come close with the "CPU activity" instrument but the results are inconsistent or don't make sense. The time profiler seems promising but all I can get is "% of runtime"... and I'd like an actual runtime.

Read the article

Does a hidden UIViewController consume any resources (iPhone)?

- by MrDatabase

My simple iPhone game has two basic "screens": home screen (UIViewController subclass) game screen (UIWindow w/ EAGLLayer where all the OpenGL drawing happens) Currently when the user taps "Play" on the homescreen the UIViewController is just hidden and the game screen is revealed. When the game is over the homescreen UIViewController is unhidden. Does the hidden UIViewController consume any resources when it's hidden?

Read the article

iPhone game w/ iTunes background music

- by MrDatabase

I've noticed some games in the app store that allow the user to play background music through iTunes. As a developer how can I add this functionality to my game? (I've searched for "open itunes from iphone game", "integrate itunes into iphone game" etc and no luck).

Read the article

Open GL ES 1.1 and iPhone games

- by MrDatabase

Will iPhone games that draw 2D textures like this: glPushMatrix(); glTranslatef(xLoc, yLoc, 0); [myTexturePointer drawAtPoint:CGPointZero]; glPopMatrix(); work with newer iPhones (that support OpenGL ES 2.0)? I'm asking because I just learned OpenGL ES 2.0 doesn't support glPushMatrix etc. Cheers!

Read the article

Why does my OpenGL ES iPhone game flicker when I first turn on the phone?

- by MrDatabase

I made a simple game for the iPhone using OpenGL ES. Everything works fine except for this problem: I turn the phone completely off, then back on, then launch my app and I get this wierd flickering! Every other frame is correct... the incorrect frames are just the same frame over and over again. If I quit the app, launch it again everything is fine. If I quit and restart 10 times in a row everything is fine every time. But if I turn the phone off, then back on, then launch the app I get the same flickering the first time I launch the app. Why is this happening?! Has anyone else had this problem? Cheers!

Read the article

iPhone game where user can choose background music

- by MrDatabase

I've noticed some games in the app store that allow the user to choose background music from their music library (iTunes). As a developer how can I add this functionality to my game?

Read the article

What are the implications of multi-tasking in iOS 4.0 for developers?

- by MrDatabase

I just watched this video from Apple that shows multi-tasking on the new iPhone (running iOS 4.0). What are the implications of multi-tasking to developers? Include both positives and negatives. For example what happens if the user decides to launch two resource-intensives apps at the same time, one of the apps crashes and progress in a game (for example) is lost. Should developers be considering this when writing apps for the new OS and phone?

Read the article

C++ header files and variable scope

- by MrDatabase

I want to organize my c++ variables and functions in the following way: function prototypes in a header file "stuff.h", function implementation in "stuff.cpp", then say #include "stuff.h" in main.cpp (so I can call functions implemented in stuff.cpp). So far so good. Now I want to declare some variables in stuff.cpp that have global scope (so I can modify the variables in functions implemented in stuff.cpp and main.cpp). This doesn't seem to work. How can I do this?

Read the article

iPhone "multi-threading" question

- by MrDatabase

I have a simple iPhone game consisting of two "threads": the main game loop where all updating and rendering happen 30 times per second (NSTimer)... and the "thread" that calls the accelerometer delegate 100 times per second. I have a variable "xPosition" that's updated in the accelerometer delegate function and used in the game loop. Is there a possibility of the two "threads" trying to use xPosition at the same time (hence causing a crash or some other problem). If so how can I fix this w/ minimal impact to the game's performance? I've been using this set-up for many months of development and incremental testing and I've never run into any problems. Cheers!

Read the article

"Multi-threading" w/ NSTimers in an iPhone app

- by MrDatabase

Say I have two NSTimers in my iPhone app: timer1 and timer2. timer1 calls function1 30 times per second and timer2 calls function2 30 times per second. Assume these two functions are reading and updating the same integer variables. Are there any "multi-threading" issues here? If not how does iPhone OS handle the execution of the two functions (in general)?

Developer IT