Yet Another Programmer's Blog

How to enable php-intl extension for php 7.1 using XAMPP on MacOS High Sierra

April 14, 2018 by blastar·0 Comments

This may seem trivial, but in fact about 2 months ago some clever guys made changes in brew repository, so doing just:
brew install php71-intl
will show you error with message that such recipe doesn’t exists. Also XAMPP comes without intl extension so is there any working solution which does not require full and manual php compilation?

Fortunately, there is. There is temporary fix in another brew repo, so all you have to do is:
brew tap kyslik/homebrew-php brew install kyslik/php/php71-intl

And this works. Really. Enjoy.

How to get UIImage from OpenGL in Swift 3

November 15, 2017 by blastar·0 Comments

As you probably notices, simple screen drawing is useless if it comes to OpenGL view. So is it possible to generate UIImage from such? Of course, lets suppose your custom drawing class extends UIView, then just add:

func getSnapshot() -> UIImage? {
    
    let s = CGRect(x: 0.0, y: 0.0, width: self.bounds.width, height: self.bounds.height)
    let dataLength = Int(s.size.width * s.size.height * 4.0)
    let buffer: UnsafeMutableRawPointer? = malloc(dataLength)
    glReadPixels(0, 0, GLsizei(s.size.width), GLsizei(s.size.height), GLenum(GL_RGBA), GLenum(GL_UNSIGNED_BYTE), buffer);
    
    let pixelData: UnsafePointer = (UnsafeRawPointer(buffer)?.assumingMemoryBound(to: UInt8.self))!
    let cfdata: CFData = CFDataCreate(kCFAllocatorDefault, pixelData, dataLength * MemoryLayout<GLubyte>.size)

    let provider: CGDataProvider! = CGDataProvider(data: cfdata)
    
    let iref: CGImage? = CGImage(width: Int(s.size.width), height: Int(s.size.height), bitsPerComponent: 8, bitsPerPixel: 32, bytesPerRow: Int(s.size.width)*4, space: CGColorSpaceCreateDeviceRGB(), bitmapInfo: CGBitmapInfo.byteOrder32Big, provider: provider, decode: nil, shouldInterpolate: true, intent: CGColorRenderingIntent.defaultIntent)

    UIGraphicsBeginImageContext(CGSize(width: CGFloat(s.size.width), height: CGFloat(s.size.height)))
    let cgcontext: CGContext? = UIGraphicsGetCurrentContext()
    cgcontext!.setBlendMode(CGBlendMode.copy)
    cgcontext!.draw(iref!, in: CGRect(x: CGFloat(0.0), y: CGFloat(0.0), width: CGFloat(s.size.width), height: CGFloat(s.size.height)))
    let image: UIImage? = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    
    return image
}

func getSnapshot() -> UIImage? {

let s = CGRect(x: 0.0, y: 0.0, width: self.bounds.width, height: self.bounds.height)

let dataLength = Int(s.size.width * s.size.height * 4.0)

let buffer: UnsafeMutableRawPointer? = malloc(dataLength)

glReadPixels(0, 0, GLsizei(s.size.width), GLsizei(s.size.height), GLenum(GL_RGBA), GLenum(GL_UNSIGNED_BYTE), buffer);

let pixelData: UnsafePointer = (UnsafeRawPointer(buffer)?.assumingMemoryBound(to: UInt8.self))!

let cfdata: CFData = CFDataCreate(kCFAllocatorDefault, pixelData, dataLength * MemoryLayout<GLubyte>.size)

let provider: CGDataProvider! = CGDataProvider(data: cfdata)

let iref: CGImage? = CGImage(width: Int(s.size.width), height: Int(s.size.height), bitsPerComponent: 8, bitsPerPixel: 32, bytesPerRow: Int(s.size.width)*4, space: CGColorSpaceCreateDeviceRGB(), bitmapInfo: CGBitmapInfo.byteOrder32Big, provider: provider, decode: nil, shouldInterpolate: true, intent: CGColorRenderingIntent.defaultIntent)

UIGraphicsBeginImageContext(CGSize(width: CGFloat(s.size.width), height: CGFloat(s.size.height)))

let cgcontext: CGContext? = UIGraphicsGetCurrentContext()

cgcontext!.setBlendMode(CGBlendMode.copy)

cgcontext!.draw(iref!, in: CGRect(x: CGFloat(0.0), y: CGFloat(0.0), width: CGFloat(s.size.width), height: CGFloat(s.size.height)))

let image: UIImage? = UIGraphicsGetImageFromCurrentImageContext()

UIGraphicsEndImageContext()

return image

}

This code works in XCode 9 and Swift 3.x.

OpenGL2: Very basic Swift3 example

August 4, 2017 by blastar·0 Comments

As you guys probably notices, it was a while since last post here. I was quite busy with lot of projects, so did not had time for blogging. Continue reading

RxSwift: How to stream values with dynamic delay

April 26, 2017 by blastar·0 Comments

Imagine such case – you have list of messages, each one with timestamp. And you want to show them in the same way they arrived, with same timings. How to achieve this with RxSwift?Continue reading

How to check object’s reference count in Swift 3?

April 25, 2017 by blastar·0 Comments

Sooner or later, you will face the problem with object which are not deallocating. How to check if object gets deallocated? Just use deinit method like below:

deinit {
    print("I'm deallocating \(self)")
}

deinit {

print("I'm deallocating \(self)")

}

If you won’t see such message when you think you class should be gone, the easiest way is to debug allocations. Because the most common reason for such behavior are strong references, you can print allocation counter this way:

print("ARC count \(CFGetRetainCount(self))")

1	print("ARC count \(CFGetRetainCount(self))")

But where to put this? First of all, in all you initialization methods. Just add some those prints after each few lines, and you should see where counter is growing. The same in cleanup methods, or if you dont have any, you can put this somewhere when your view controller is closing, like:

self.dismiss(animated: false) {
            print("VC is closing \(self.myobject)")
        }

self.dismiss(animated: false) {

print("VC is closing \(self.myobject)")

}

And how to avoid strong references? The most common mistake, is using self in blocks, this is the place where you should use [unowned self], this way:

Timer.scheduledTimer(withTimeInterval: 1, repeats: true, block: { [unowned self] (timer) in
                self.myobject.doSomething()
            })

Timer.scheduledTimer(withTimeInterval: 1, repeats: true, block: { [unowned self] (timer) in

self.myobject.doSomething()

})

How to use JSContext from JavaScriptCore to create two way communication with web page

February 6, 2017 by blastar·0 Comments

What is “JavaScriptCore”? Well, it is a name for internal Safari javascript engine. Is it useful? For most of us it is not, but if you thinking about communicating between your Swift app and web page, it can be really useful.
Continue reading

Fatal error: unexpectedly found nil while unwrapping an Optional value

January 26, 2017 by blastar·0 Comments

This can be really painful when you just started with Swift. It really happens very often and can be confusing. Where it comes from?Continue reading

interfaceOrientation is deprecated in iOS8

December 6, 2016 by blastar·0 Comments

Are you still using self.interfaceOrientation and getting deprecation warning? Well, don’t. Not only because it is depracated, but it can give you wrong result. Device might be in landscape mode, but a view controller that only supports portrait will remain in portrait. Solution for everything is:

[[UIApplication sharedApplication] statusBarOrientation]

1	[[UIApplication sharedApplication] statusBarOrientation]

which will not only return correct orientation, but also result is UIInterfaceOrientation enum so you don’t need to change your switches.

Jenkins & XCode: User interaction is not allowed when executing task

November 25, 2016 by blastar·0 Comments

Getting “User interaction is not allowed” error in your build task? If yes, solution is very simple. Just login your build user (usually “jenkins”) via the GUI (which means VNC) and open Keychain Access. Select your signing private key, right-click, choose Get Info, change to the Access Control tab and select the “Allow all applications to access this item”.
Now error should be gone.

Swift 3: Unexpected nil when using NSCoder

November 4, 2016 by blastar·0 Comments

If you were using NSCoder in Swift 2, I’m pretty sure you used such code:

decoder.decodeObject(forKey: "name") as! String decoder.decodeObject(forKey: "number") as! Int

Now, in Swift 3, using such construction, will cause:

fatal error: unexpectedly found nil while unwrapping an Optional value

So is there any solution for this? Yes, you need to use explicit methods to integers, floats, bools and some other types. Just rewrite this code as:
decoder.decodeObject(forKey: "name") as! String decoder.decodeInteger(forKey: "number")

And this error will be gone. Available methods below:
decodeBool decodeInteger decodeCInt (returns Int32) decodeInt32 decodeInt64 decodeFloat decodeDouble decodeBytes