After a T-Mobile update to Android Pie, my Always on Display was no longer displaying. It seems like in Pie it initially defaults to only displaying with a touch to the screen. To change this, go to Settings, Lock Screen -> Always on Display – some of these setting screens have additional options if you scroll down. For example, the AoD settings page initially looks like this:
… but if you scroll down you’ll see additional options, including ‘Display Mode’:
Press Display Mode and change from ‘Tap to Show’ to ‘Show Always’ :
It’s been a year and a half since I’ve given an update on my Space Invaders clone on Android. Admittedly I haven’t been working continuously in my spare time on this project for 18 months, in fact the last time I remember working on it was several months back. What I got stuck on was updating the animation routines so the animation would display with a constant frame rate across different Android devices, and the display of the sprites to look consistent for devices with different sized screens, resolutions and pixel densities.
If you’re a seasoned game developer this is probably nothing new to you. If you only develop for a platform with identical hardware specs (like a game console) then this is probably something you don’t have to worry (too much?) about. However with the broad range of specs for Android devices, even testing with the device emulator for different phones, it’s pretty obvious unless your code handles these differences, your game might be fast on one device but slow on another, or the sprite layout may look at intended at the resolution on one phone but be too small on another phone.
I spent a bunch of time reading game dev articles about implementing approaches for constant frame rates, and tried to incorporate what I’d learned, but still, I’ve got some weird quirks I need to iron out.
Here’s what the game looks like on an emulated Pixel:
I was initially developing and testing on the emulated Nexus devices as my baseline test target, but it runs fine, as expected on the Pixel too (it’s harder to play when pressing the buttons with the mouse!).
Now running on an emulated Pixel 2 XL, it runs fine for a while until the number of invaders gets down to where I speed up. The speed up is too fast, and then for some reason that I haven’t found yet they animation stops before the game ends but the game is still playing:
Clearly I’ve still got some work to do here, but it’s getting close.
I’ve been running custom CyanogenMod builds on my now aging Galaxy S3 for a while now (12.1, 13). Given that support for CyanogenMod ended at the end of last year, I thought it would be worth one last new ROM before I upgrade my phone this year, and installed the new LineageOS.
Using the already installed TWRP recovery that I already have installed, I downloaded the latest nightly LineageOS build from here, the latest Google Apps for Android 7.1 from here, booted into Recovery, deleted cache files etc, installed both new ROMs and now I’m up and running.
Even on my aging Galaxy S3, I have to say, this Android 7.1 build is surprisingly snappy, even faster than the last CyanogenMod build that I had that was pretty good.
Earlier this year I started developing a Space Invaders inspired game for Android. I started back in March, and have worked on it for a around 20 to 30 hours or so, on and off. Not being an expert in Android development or game development in general, it’s been a learning experience. The book I read back in March, Android Game Development by Example, was a good book to get started. I realize I probably could have got to a playable game quicker if I’d used a game development platform like Unity3d, but I wanted to get to grips with writing a game by from the ground up first. I’ll circle back and probably rewrite it using something like Unity later.
Right now I’m at a point where it’s playable but there’s a few key features I still need to add, like the bases/shields at the bottom of the screen, and the invaders need to shoot missiles at the player. It’s a pretty easy game at this point 🙂 I have a few ideas for some gameplay variations to add too.
I started implementing as a standalone Java app using the Java2d api and the 2d game engine that I’d previously worked on for my first attempt at a game in Java, a version of one of the classic Nintendo Game n Watch games, Turtle Bridge.
I tried to replicate the animation of the invaders moving one at a time, one row at a time and got pretty close:
Compared to current day AAA tier video game development projects which typically have multi-million dollar budgets and teams of artists, story writers, sound engineers, QA, developers, as well as marketing and PR teams, I find it fascinating that Space Invaders was originally developed by a single developer, Tomohiro Nishikado. Not only did he develop the sofware for the game, but he also designed the hardware on which the game runs.
There’s some interesting features of the game that were not part of the original design, but resulted from limitations of the hardware. For example, the invaders speed up as fewer are left remaining on the screen. This is a defining feature of the game, but was a side effect from the 8080 processor being unable to animate a full screen of invaders at the same speed compared to a screen with only 1 or 2 remaining. Rather compensate in software to keep a constant frame rate, this feature was kept.
Other features in the game play logic could easily be overlooked by a casual player:
The mystery ship appears on a regular, timed basis, at around each 25 seconds
The mystery ship is worth 300 points on the first 23rd shot on each screen, and then 300 on every 15th shot for the remainder of the screen. For all other shots it’s 100 points (if you play for high scores, then this fact is probably very well known to you 🙂 )
Missiles from the invaders will not kill the player if fired from the last row on the screen
Here’s a quick video of how far I’ve got so far. This is running on a device simulator, so the frame rate is not as fast as on a real device:
I’ve still got some work to do, but I’m pleased on my progress so far.
