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.