Chirp!

This article covers how to inject associated domain to your GameMaker game, using the built-in Code Injection field in a GameMaker iOS extension.

Why do you need the associated domain "applinks" string?

To link an associated domain to your iOS app, one of the several steps is that you need to build the string "applinks:yourFullyQualifiedDomain.com" to the app archive by adding this capability to your XCodeProject. There are many tutorials on how to do it on the internet which covers all the other steps.

What happens if this string is added manually to XCode?

If you manually insert this string into XCode, GameMaker will overwrite it every time you build your game, because it's regenerating the XCodeProject, overwriting whatever you modified.

How to do it properly in GameMaker

It's possible you use a post install script to do it. However, the GameMaker way of doing it, is by "Code Injection" during the build process. Basically GM loads in its template .xcodeproj and replaces predefined strings with your extension settings.

Here in GM manual is a list of predefined strings for iOS Code Injection:

To add the "associated domain" capability, what we're looking for is YYIosEntitlements. Add the following into any iOS extension's "Code Injection" field:

<YYIosEntitlements> <key>com.apple.developer.associated-domains</key> <array> <string>applinks:yourFullyQualifiedDomain.com</string> </array> </YYIosEntitlements>

Save and build the GameMaker project. You should see that the associated domain is written into your "Capabilities & Entitlements" section.

What to do next

You can also enable developer mode to test the universal link behavior.

More and more often I see beginner coding questions on gamedev forums and think: hey, this is easily solvable by ChatGPT! It is practical, has no temper, and it won’t judge you. It may take some practice to get things right, but it works pretty well most of the time.

Here are two simple examples I’ve tried.

1. Write me a function in {language} that does this thing.

2. Shorten these lines. 

If the outcome isn’t good enough, just interactively ask it to rewrite. You don’t have to be polite, nor grammatically correct. For example:

1. The argument in degrees, not radians.

2. Only 1 arg. 

3. No data structures, just math.

It’ll even comment and explain what it did, and give you examples of how to use the code. No need to ask other human beings to do it for you anymore. 

This is on my good old MBA, with macOS High Sierra. I need to use cocoapods and ruby “xcodeproj” gem for GoogleMobileAds + mediation. I had used it quite some time before, but switched to another MBP where latest XCode is available, so environment on this MBA is quite outdated.

cocoapods can be updated with “pod update” fine; however it prompts me to update cocoapods itself with “sudo gem install cocoapods”. Running that gives an error “ERROR: Failed to build gem native extension.” and suggestion “You have to install development tools first.”. Looks like my ruby itself is outdated.

So, “brew install ruby” time. Before that can happen, “brew update” to update homebrew itself. 

“brew install rbenv ruby-build” seems to be needed.

Most importantly “xcode-select install” the xcode command-line tools, since the failure logs showed that ‘ruby/config.h’ is not found when building native extensions.

ActivityManager: START u0 {act=com.google.android.gms.auth.GOOGLE_SIGN_IN pkg=com.google.android.gms cmp=com.google.android.gms/.auth.api.signin.ui.SignInActivity (has extras)} from uid 10100 on display 0

02-07 04:38:47.372  9367  9367 I AppCompatDelegate: Failed to instantiate custom view inflater android.support.v7.app.AppCompatViewInflater. Falling back to default.

Also I got Saved Games data conflicts that never end; server-side timestamp is always ahead of my local copy. Turns out it’s just the emulator having incorrect automatic time zone; I changed it to a manual correct time zone and things go correct now. Silent sign-in works, and the interactive sign-in activity does not hang on a dimmed blank screen on me. No ApiException nor ClassNotFoundException on multidex application whatsoever. Woot???

So, Android emoji support had been added since 4.3, that was released back in 2012. Code name: JELLY_BEAN_MR2

https://emojipedia.org/google/android-4.3/

https://developer.android.com/reference/android/os/Build.VERSION_CODES

I used “gem stone” and “party popper” in my game’s local notifications. If a system font does not support some emoji, the “tofu” glyph should be displayed at the specific location. However, I was seeing glitched texts such as “xxxxx” or “ p” or “盹” etc. on my Android 4.4 test device.

What’s going on then? Turns out it was casued by me hardcoding “💎” and “🎉” in my json files as well as in gml scripts. Notification extension’s Java source code does not accept such characters. My dirty workaround is to store “:gem:” and “:tada:“ instead, and replace them in Java source with  "\uD83D\uDC8E" and  "\uD83C\uDF89". (Fun fact: GMS does not allow such code in gml scripts!)

References:

- https://emojipedia.org/gem-stone/

- https://emojipedia.org/party-popper/

- “:gem:” https://www.fileformat.info/info/unicode/char/1f48e/index.htm

- “:tada:” https://www.fileformat.info/info/unicode/char/1f389/index.htm

App stores keep lots of localizations and prices across countries; both Apple and Google kindly returns preprocessed price strings so we app developers don’t have to handle all kinds of currency symbols and where they go (some at front and others at back). However, if you’re rendering texture fonts like I do you’re likely in trouble. Not all fonts support all currency signs and we don’t know what we’ll receive.

Unicode blocks list all kinds of currency symbols here and there so are we done? Not so luckily. In Asia we have halfwidth and fullwidth symbols hooray! Who knows what we’ll receive? Thank god I’m not the first person trying to resolve such issue. Kudos to Japanese people; they’re probably worlds’ most font-savvy people. Takumi master craftsman spirits!

Perhaps it’s simply tips for using CocoaPods-generated xcworkspace:

- after (any?) pod install: click into pods, select each pod and modify deployment target to 8.0 or anything above minimum supported version (https://stackoverflow.com/questions/37160688/set-deployment-target-for-cocoapodss-pod)

-  also, click into gamemaker generated xcodeproject, and select each target, to add $(inherited) to all framework/header search paths.

-----

Things to add to newly generated .xcodeproj

- infoPlist.strings (localized “CFBundleDisplayName”, “CFBundleName”) [ref]

It’s been great since I’ve moved from HeyZap to AdMob now that rewarded ads are supported and mediation adapters are well maintained. CocoaPods are superb! It makes iOS package management a lot smoother. It’s also somewhat similar to gradle, making it easier to switch my mental status when making mobile app builds.

One thing that confused me for a while is that when using adapter pods like GoogleMobileAdsMediationUnity, CocoaPods never installs the latest ad SDK. It leaves “pod outdated” with all red, and my runtime logs are also crammed with mediated SDK complaints saying that I’m not using the latest version.

The reason is simple: adapter pods are maintained by Google and they won’t always keep up with ad SDK companies. Fortunately it is easy to resolve, if the new ad SDK didn’t come with adapter breaking changes. 

“pod spec edit GoogleMobileAdsMediationUnity” is the magic command to resolve the issue. Simply edit the dependencies to the latest version number, or >= the specified number will allow “pod update” to pull the latest version.

So AdMob’s MediationTestSuite Beta requires CocoaPods to work. 

Install it, run  my test GMS2 AdMob project from PC.

Find the .xcodeproject folder in ~/GameMakerStudio2/iOS/GMS2IOS/{project_name_folder}/{project_name_folder}

Run “pod init” at the same level of the .xcodeproj folder, where the __yy_certificate.xconfig file sits in.

vim Podfile, add the following after # use_frameworks!

pod ‘GoogleMobildAdsMediationTestSuite’

pod ‘GoogleMobileAdsMediationUnity’

Run “pod install --repo-update” as described [here].

Wait for pod setup.

I got a couple of warnings [!]:

Unable to read the license file `LICENSE` for the spec `UnityAds (3.0.0)`

... target overrides the `HEADER_SEARCH_PATHS` 

... target overrides the `LIBRARY_SEARCH_PATHS`

The last one turned out to be immediately harmful. Fortunately they also come with solution hints:

Use the `$(inherited)` flag,

And so I did. Open pod generated `project.xcworkspace` file instead of the old .xcodeproj.

Under Project navigator -> TARGETS -> Build Settings -> Search Paths -> Header Search Paths & Library Search Paths.

Double click on the value strings (starting with $(PROJECT_DIR) etc), click `+`, type in $(inherited). Build success! With the following modifications added into AdMob.mm.

#import <GoogleMobileAdsMediationTestSuite/ GoogleMobileAdsMediationTestSuite.h>

// although doc says @import  GoogleMobileAdsMediationTestSuite; 

// we can’t do that because we use .cpp 

NSString *appID = @”ca-app-blablabla~blablabla”;

[GoogleMobileAdsMediationTestSuite presentWithAppID:appID

onViewController:g_controller

delegate:nil];

It displays, and can even load UnityAds fine! Hooray! 

Destination reached! Successfully done MediationTestSuite.launch on Amazon Kindle Fire HD 8″. GMS2 IDE v2.2.1.375 Runtime v2.2.1.291

GMS2 Build Settings (Pre-populated API Level 26, with min SDK 16 although AdMob MediationTestSuite falsely claimed min 14; crashed[*] with API Level 27, build failed with duplicate entry class with API Level 28):

Build Tools 26.0.0

Support Library 26.0.0

Target SDK 26

Minimum SDK 16

Compile SDK 26

Inject to Gradle dependencies:

  compile 'com.google.android.gms:play-services-games:16.0.0'   compile 'com.google.android.gms:play-services-ads:17.1.3'   compile 'com.google.android.gms:play-services-plus:16.0.0'   compile 'com.google.android.gms:play-services-gcm:16.0.0'   compile 'com.google.android.gms:play-services-auth:16.0.1'   compile 'com.google.android.ads.consent:consent-library:1.0.7'   compile 'com.google.android.ads:mediation-test-suite:0.9.3'   compile fileTree(dir: 'libs', include: ['*.jar']) } repositories {  maven  {    url "https://maven.google.com"  } } dependencies {

Inject to AndroidManifest.xml Application:

<activity android:name="com.google.android.gms.ads.AdActivity" android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize" />

<meta-data            android:name="com.google.android.gms.ads.APPLICATION_ID"            android:value="ca-app-pub-YOUR_APP_ID~YOUR_APP_ID"/>

Hard-coded mAppId String in GooglePlayServicesExtension.java; tested with LoadInterstitial, calling .launch in UI thread:

import com.google.android.ads.mediationtestsuite.MediationTestSuite;

public void GoogleMobileAds_LoadInterstitial() { RunnerActivity.ViewHandler.post( new Runnable() {     public void run()     { if(interstitialAd==null) initInterstitial(); AdRequest.Builder builder = new AdRequest.Builder(); builder.addTestDevice(AdRequest.DEVICE_ID_EMULATOR); if( bUseTestAds) builder.addTestDevice(TestDeviceId); AdRequest adRequest = GoogleMobileAds_BuildAdRequestWithConsent(builder);

// Load the interstitial ad. interstitialAd.loadAd(adRequest);

           // struggling to launch the MediationTestSuite            RunnerActivity.CurrentActivity.runOnUiThread(new Runnable() {                public void run() {                    MediationTestSuite.launch(RunnerActivity.CurrentActivity, mAppId);                }            }); }});

還沒實測 mediation adapter，希望真的不用自己寫Ad SDK測試啦。

Update 18 Feb 2019:

Can’t load (Unity) ads from within MediationTestSuite UI. I was however able to check the SDK installation and settings fine and load/display Unity test ads.

[*] API Level 27 Crash ref: 

W/Ads: #004 The webview is destroyed. Ignoring action.

I lied in the title. I really appreciate the fact that .yy files are in JSON format so I can copy paste NodeJS code from StackOverflow to modify them out of GameMaker Studio. Caution: ugly copy pasta code snippet below. I used my rooms’ view camera 1 to create in-editor highlight area.

Just like that many other variable-length functions do not work properly in html5 export, shader_set_uniform_f sometimes does not work properly when setting vec4 uniform values.

Workaround: use shader_set_uniform_f_array instead.

Mobile safari has this graceful start that sounds in any web page only play after user interaction. Which is great! I certainly don’t want accidental taps on ads or anything —NSFW— to broadcast loudly without permission.

It’s nice, until its voodoo magic starts to mess with my game’s music loops.. I had to accept the fact my cover page is muted, I can live with that, people need to click and make sure they got the browser focus right anyway.

But but but then I had to check whether my music is playing, and the checks failed mysteriously. I originally had my code in Room Start as well as Any Key Pressed — the music not only sometimes plays multiple times mixed together, but also plays when mobile safari is in the background, and even once through my Bluetooth speaker when I connected it to my phone woot?

So network bandwidth sucks at times. You never know. Unless it’s simulated by Chrome developer tools. Img1: Disable cache + Slow 3G.

Img2: 926KB mp3 file taking more than 1 min to download

That makes a good loading bar very important. Heck, people may even stare at that bar longer than they play a shitty mini game!

GMS2′s default loading screen is one of the following two options:

- a splash screen image

- a default loading bar

If you want anything more, you’re allowed to customize using a JS extension. Somehow I don’t see where it is documented in the official doc, but thankfully many [great tutorials] had shown how to do that. I was also able to find free extensions in the gms marketplace as a good starting point to modify the code. 

I’ll just add some more notes here:

Q: How to make my extension’s function available for selection in that “loading bar extension” drop-down menu under Game Options -> Html5 -> General? I did not see it!

A: There are 2 things to make sure: 

(1) You need an extension with a function that matches the signature (generally speaking, it means: return type, and the number of parameters and their types) of a loading bar callback function. If you’re making a new extension, simply create a JS file, add a function to it, and in function parameters editor, click the plus button 6 times (to add argument0 to argument5). It does not even need an “external name”. Since JS is weakly typed and flexible, the return and argument types need NOT to be set to “double”. (I still did it for clarity.)

(2) Also in order to match the signature, make sure there is no “Variable Length Parameters” option checked for the extension function. If the checkbox is empty, toggle it a couple of times to make sure the internal setting’s sync with the IDE’s GUI.

Note: (x, y) are integer grid indices, not room coordinates.

So The Book of Shaders connects 2 smoothstep() to plot things. The variable names aren’t super clear. 

- pct is short for percentage (... come on shader people, use clear names at least in examples)

- color = mix(color1, color2, percentage); // plotted = color2; percentage = plottedness ranging from 0.0 to 1.0

- float thickness = 0.02;

- float aboveness = smoothstep(plotted_y - 0.02, plotted_y, fragment_y); // anything with fragment_y > plotted_y has 1.0 aboveness, also fragements with fragment_y > plotted_y - 0.02 are smoothly, gradually tinted with color2

- float high_aboveness = smoothstep(plotted_y, plotted_y + 0.02, fragment_y); // try replace this with step(plotted_y, fragment_y) --> not smooth at all

We’re allowed to use GLSL ES shaders in Gamemaker: Studio 2. The first time I learned about GLSL was roughly ten years ago (2009-ish). Achieved nothing other than creating a mobile app surface displaying a rotating triangle whose colors shift while it rotates. That, and scaring off a colleague who was willing to work with me on mobile games. It simply took me too much time to build from scratch without help of game engines. I buried my GLSL bible since then.

Now I have GM:S2 and a more focused, pragmatic mind; time to re-learn GLSL. It’s great to be able to draw 2D screen transition effects with fragment shaders! Took me less than 2 days to draw something useful, which is good imho. 

Lessons learned:

- shader_set and then draw_surface(application surface, 0, 0); easy!

- shader_get_uniform, shader_set_uniform_f to communicate with shaders

- gm_BaseTexture is our lovely sampler2D (ref: shader constants)

- Precision is important! Append . to any floating point digits: 1.,2.