Bug in Apple's 'GLPaint' sample - dot always drawn before line - problem in touchesBegan/Moved/Ended

Posted by Adam on Stack Overflow See other posts from Stack Overflow or by Adam
Published on 2010-05-03T18:25:02Z Indexed on 2010/05/03 18:28 UTC
Read the original article Hit count: 303

Filed under:

opengl

|

iphone

|

touchesmoved

|

apple

|

sample

I was just messing around with Apple's GLPaint sample app to learn more about OpenGL, and I noticed that whenever you draw a line, it's always preceded by a dot. Basically, it looks like:

.________

Does anyone know why this happens? I'm guessing it's some weirdness with touchesBegan/Moved/Ended, but I can't verify. It's been driving me crazy all morning!

© Stack Overflow or respective owner

Related posts about opengl

Unity completely broken after upgrade to 12.10?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I am facing a very frustrating issue with my computer right now. I successfully upgraded to Ubuntu 12.10 this afternoon, but after the upgrade, the graphical user interface seems completely broken. To be more specific, I can not get the Unity bar to appear on the right. I have tried many things,… >>> More
OpenGL or OpenGL ES

as seen on Game Development - Search for 'Game Development'
What should I learn? OpenGL 4.1 or OpenGL ES 2.0? I will be developing desktop applications using Qt but I may start developing mobile applications in a few months, too. I don't know anything about 3D, 3D math, etc and I'd rather spend 100 bucks in a good book than 1 week digging websites and going… >>> More
OpenGL extension vs OpenGL core

as seen on Programmers - Search for 'Programmers'
I was doubting: I'm writing a cross-platform engine OpenGL C++, I figured out windows forces the developers to access OpenGL features above 1.1 through extensions. Now the thing is, on Linux, I know that I can directly access functions if the version supports it through glext.h and opengl version… >>> More
OpenGL ES 2/3 vs OpenGL 3 (and 4)

as seen on Game Development - Search for 'Game Development'
I have migrated my code from OpenGL ES 2/3 to OpenGL 3 (I added bunch of defines and abstract classes to encapsulate both versions, so I have both in one project and compile only one or another). All I need to change was context initialization and glClearDepth. I dont have any errors. This was kind… >>> More
LWJGL - Eclipse error [on hold]

as seen on Game Development - Search for 'Game Development'
When I try to run my lwjgl project, an error pops . Here is the log file: # A fatal error has been detected by the Java Runtime Environment: # EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x6d8fcc0a, pid=5612, tid=900 # JRE version: 6.0_16-b01 Java VM: Java HotSpot(TM) Client VM (14.2-b01 mixed… >>> More

Related posts about iphone

iphone - direct link to iPhone review form from inside iphone

as seen on Stack Overflow - Search for 'Stack Overflow'
I am trying to link directly to the review link of one of my Apps. I know that it is possible because Appirater did it in the past, but some change in iTunes turned the API down. Appirater uses this URL NSString *templateReviewURL = @"itms-apps://itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews… >>> More
Buy iPhone 4 Without Contract: $599 (AT&T) and $699 (Verizon)

as seen on Tech Dreams - Search for 'Tech Dreams'
Purchasing iPhone without a contract is a good option when you are planning to gift it to someone or going to use it outside US. Both AT&T and Verizon lets you iPhone 4 without a contract but this information is buried deep under blurred text in FAQs and agreements. Here is the pricing… >>> More
Is it possible to download and run IPhone apps on an IPhone emulator

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am tasked to provide an IPhone client app for our SaaS website. I have never written an IPhone application, nor do I have an IPhone at the moment. Before I can decide whether or not I want to do this myself or outsource this, I'd like to try a few apps myself to get a feeling for the UI. Is… >>> More
iPhone web app from dashcode rss feed template works deployed on simulator but not on iphone

as seen on Stack Overflow - Search for 'Stack Overflow'
iPhone web app from dashcode rss feed template works deployed on simulator but not on iphone. The web app is deployed at; http://www.alila.se/wordpress/index.html If i run the simulator and enter that adress, it fetches the rss feed and displays it. Everything fine. When i enter the adress into… >>> More
Problem running iPhone application on iPhone from Xcode (and in Instruments)

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi I have a problem running one application on the iPhone from Xcode (or Instruments). When I try to run the app I get the error message Failed to upload XXX.app in the bottom left corner of Xcode. The strange thing is it actually uploaded the app to the iPhone but it doesn't start it (after this… >>> More