Xcode Issues: How To Work-Around An Ineligible iOS Device

There may come a day, a sad day, when you install the latest version of Xcode, plug-in you iOS device, wait for it to appear in the list of scheme supported devices, and…nothing. Then you click on the scheme pull-down menu and see the following,

Xcode Ineligible Device Post 03 15 2015 Img 1

How did your iOS device become ineligible for development? Well, I don’t know and nobody else seems to have an answer. But there is a work-around Continue reading

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GLKit – Transforming A Vector With A Quaternion

Since I haven’t seen this on Stackoverflow, the following is a method to transform a vector (GLKVector3) based on an attitude quaternion (GLKQuaternion).

First, assume that you have a GLKVector3 as input, call it inputVector3. inputVector3 could be yaw, pitch, and roll influences from an aircraft’s control surfaces or thruster output on a spacecraft. You know your vehicle’s attitude and have calculated that attitude into a quaternion. So, the goal is to have the inputVector3 transformed into an ivar, say GLKVector3 deltaV, that is in terms of the vehicle’s attitude.

– (GLKVector3)transformVector3:(GLKVector3)inputVector3 withAttitudeQuaternion:(GLKQuaternion)attitudeQuaternion
GLKVector3 deltaV = inputVector3;

//Always ensure that your attitude quaternion has been normalized
attitudeQuaternion = GLKQuaternionNormalize(attitudeQuaternion);

//Convert the normalized attitude quaternion into a GLKMatrix3.
GLKMatrix3 tempQMatrix3 = GLKMatrix3MakeWithQuaternion(attitudeQuaternion);

//Since v’ = v T, where T is a transform matrix, multiply
//the attitudeQuaternion GLKMatrix3 with the necessary GLKVector3.
deltaV = GLKMatrix3MultiplyVector3(tempQM3, deltaV);

return deltaV;

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REST/JSON/CoreData App Tour

When: February 28, 7:00 PM

Where: TechShop
120 Sundance Parkway, Suite 350
Round Rock, TX 78681

From 7:00 – 7:30, it’s Show-&-Tell. So bring your code and your apps and show them off.

Carl Brown will give us a tour of an example open-source (MIT license) app he wrote to illustrate using a REST (web) API with JSON and Core Data. The source code is at http://github.com/car… if you want to follow along.

Posted in Update

GLKit Night

When: February 21, 7:00 PM

Where: TechShop
120 Sundance Parkway, Suite 350
Round Rock, TX 78681

From 7:00 – 7:30, it’s Show-&-Tell. So bring your code and your apps and show them off.

This will be GLKit Night. GLKit is Apple’s way of making OpenGL ES more approachable and easier to use for developers. And what’s not to like about GLKit or -snapshot?

Rajat will talk about GLKit and shaders. While GLKit tries to shade one from having to write Shaders, sometimes you just have to shade. For example, let’s say you want shadows? After Rajat finishes, you’ll be have a better understanding of both GLKit, shaders, and how they can work together.

Jim will talk about his experience with GLKit in building his ISS Space Station app. There isn’t a lot of sample code on how to use GLKBaseEffectGLKMatrixStack, and even how to build a nice spotlight, so his presentation will hopefully help those wondering how to shove your GLKBaseEffect instance into GLKMatrixStack.

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10 years ago, the CocoaCoder.org site was created with Apple’s iWeb. And for the past 10 years, CocoaCoder.org was updated with iWeb. iWeb, if you’ve never heard of it, was one of the most beautiful web site creation tools around. The elegance of the site template designs made all others look…well, cheap or gaudy. Through hard work, one could create an ugly website with iWeb, but if you followed the iWeb templates you were pretty much guaranteed a site that you would never be unhappy to show-off as a non-web programmer.

Several years ago, Apple decided to end development of iWeb. No reason was given. CocoaCoder.org held-on as long as possible to its iWeb-designed site. But when Apple suspended support for iWeb’s built-in widgets, meaning no more support maps for one, it was time for the site to move on.

It is hoped that you like our new site built on WordPress.com. It is still a work in progress, but the features of the original CocoaCoder.org site will be built-in to the new one. In fact, if anything, moving to WordPress.com allows us to focus on creating content that we can then push to the many widgets that WordPress.com supports.

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