temp zip file is now deleted after download

core/src/com/unciv/ui/worldscreen/mainmenu/DropBox.kt

@@ -219,5 +219,6 @@ object Zip {
                 extractFolder(destFile, unzipDestination)
             }
         }
+        zip.close() // Needed so we can delete the zip file later
     }
 }

docs/Game Making Tips.md

@@ -14,11 +14,17 @@ I regret every minute that I spent writing events in Java, this is probably the
 
 Unless you plan on creating images on the fly, you'll probably be using prerendered assets.
 
-Placing them manually of akin to manually positioning html tags, instead of using html heirarchy and css to guide positions.
+Placing them manually is akin to manually positioning html tags, instead of using html heirarchy and css to guide positions.
+
+So too is Scene2d - as a placement framework. it's relatively simple to understand, especially when you...
 
 ## Ignore Horizontal and Vertical groups - use Table
 
-I personally found that table has all the functionality of the above, and more. Each class has a different syntax too, so I found it much simpler to just stick with Table for everything.
+I personally found that table has all the functionality of the above, and more.
+
+Each class has a different syntax too, so I found it much simpler to just stick with Table for everything.
+
+Table does just about EVERYTHING! It's insanely amazing!
 
 ## If your game is getting slow, use the Android profiler in Android Studio
 
@@ -26,9 +32,113 @@ The top-down CPU chart is the best code profiler I've ever seen, use it to your
 
 ### Cache everything
 
-caching is a trade-off between purer, state-agnostic code and higher performance.
+Caching is a trade-off between purer, state-agnostic code and higher performance.
 Coming from a PC background, I automatically assume that anything less than O(n^2) is less than a milisecond and therefore, not a cachinhg candidate.
 This is not so in mobile development.
 
 
- This becomes especially relevant when you need to save and load game data which has lots of connected parts - you have to avoid circular references, and you want to minimise the save size, but you need to reconstruct the missing links when loading.
+This becomes especially relevant when you need to save and load game data which has lots of connected parts - you have to avoid circular references, and you want to minimise the save size, but you need to reconstruct the missing links when loading.
+
+### Minimize String operations
+
+
+All the tip and tricks you've heard to minimize String operations? Use them!
+
+String constants should be consts, use StringBuilders (or just ArrayLists of strings that you later .joinToString())
+
+### Sequences everywhere!
+
+One thing I did not expect to be such an issue is intermediate lists when sorting and mapping.
+
+But appparently, the memory allocation for these tasks is Serious Business.
+
+So whenever possible, take your list and .asSequence() it before actiating list operations - this results in huge savings of both time and memory!
+
+The only time you shouldn't be doing this, though, is when you want to cache the specific values for future use -
+ sequences will go through the whole process every time you iterate on them, so just .toList() them when you've gotten the final results!
+ 
+# General tips for making an Open Source game
+
+## Lower the entry bar - for both programmers and players
+
+I think that most Open Source games suffer from this problem - those that are in are way in, but those that are out and want to join have to learn the ecosystem.
+
+Documentation is a big issue here, but so are detailed instructions - and I mean "Spoonfeeding".
+
+Treat new developers as if they've never used Git before - it's possible they haven't!
+
+Explain how to dowload the sourecode, the tools, how to get the game running locally, how to make changes and how to submit them.
+
+Same think with new players - getting the game up and running should be AS SIMPLE AS HUMANLY POSSIBLE - you want people to play your game, don't you?
+
+This includes:
+
+- Source-To-Executable automation - I use Travis
+- Play stores and the like
+- Internal game tutorials - your players will NEVER BE SATISFIED with this last point, but at least do what you candidate
+
+## Community, Community, Community!
+
+I, personally, underestimated this point for about a year after launch.
+
+I communicated with players through the Google Play Store and Github issues, and that seemed to be enough.
+
+It was only after repeated urgings from players that I opened a Discord server - and that gradually lead to a massive change!
+
+You see, it's not ABOUT programmer-to-player interaction. There will always be a small number of core devs relative to the large playerbase.
+
+The key to the community is the player-to-player interaction. Explaining things, questions, ideas, things that players bounc off each other,
+not only make the amorphous community a better pllace, but actually lead to a better game!
+
+Another think to remember is that there's a larger community around you - the Open Source community, the Linux community, etc.
+
+There are lots of people who will play your game only because it's open source, and it also means they don't have as many options.
+
+For example... 
+
+- Being the best 4X game means competing with the biggest names out there
+- Being the best 4X game for Linux means many less competitors
+- Being the best Open Source 4X game means about 5 competitors
+- Being the best Open Source 4X game for Android... means having no competitors.
+
+## Everything is marketing.
+
+Your game's name, the icon, screenshots, everythig a player sees about your game is marketing.
+
+Icons and bylines are especially improtant, since they're the first things your players will probably see.
+
+I saw an almost 50% (!) by changing the icon, after seveeral experiments, which Google Play lets you conduct very easily.
+
+## Translations are part of your source code
+
+This may be slightly contraversial, so I'll explain.
+
+We went though a number of iterations regarding how to save translations until we arrived at the current format.
+
+The important parts are:
+
+- Game translation files should be AUTO GENERATED. This allows you to add new objects into the game with impunity,
+ knowing that corresponding lines will be auto-added to the translations.
+ 
+- Translations for each language shoule be stored separately - this allows concurrent modification of several independant languages with no risk of conflict
+
+- Translations should be PR'd in! This allows other speakers to question or change the proposed translations, and allows you to run tests on your translations.
+If you require a specific format, this is invaluable as it means that bad translations will be rejected at the door.
+
+## Open source problems require open (source?) solutions
+
+TL;DR, consider using APIs that are free, even if they're not Open Source.
+
+Multiplayer requires syncing game files beween clients, even when one of them is not currently online.
+
+The 'correct' way to solve this would probably be to have an online DB and a service which handles user requests.
+
+Since this is an Open Source game, I'm working on a 0$ budget, so we just store all the files in Dropbox and upload/download there.
+
+Is this secure? No, but does it need to be? You need to think of the cost vs the value.
+
+Same thing with Mods. Steam handles its mods itself.
+
+We just allow to download from Github, which lets us use all of Github's built in functions (user management, readmes, stars, versioning...) at no extra cost.
+
+And unlike the Dropbox usage, with is masically abuse, Github is built for thiss kind of thing! This is exactly the kind of use case they were thnking of to start with!