About leffe108


Ludum Dare 36
Ludum Dare 35
Ludum Dare 33
Ludum Dare 32
Ludum Dare 31
MiniLD #53

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Location based games

Posted by
Tuesday, July 19th, 2016 7:02 pm

Now that everyone(?) is playing location based games, if you like to make your own, it is actually not that hard to get a basic game up and running. Especially if you only need it to work when your app is in the foreground. From there you can add more and more content or mix with open data.

You may be interested in my previous post How to make a location based game where I walks through the main parts of writing a location based game using web standards. In addition to that, you can also dig into the source code of Shapes Outdoor on github.

I mean, I enjoyed a top 100 on innovation, but I like to share the knowledge so that hopefully there will be many more location based games in the next Ludum dare where you innovate on more innovative ways to use the location. :-)

Rules question: Map tiles and open data
I won’t have the time to participate the next LD, but for others, it may be a good idea to clear up regarding the LD compo rules if map tiles are allowed or not. In my entry I played safe and didn’t use any map tiles, but it may be a good idea to have this documented perhaps also along with whether or not you are allowed to use public APIs like finding nearby POIs (points of interest) using eg. OpenStreetMap API, national APIs etc. Typically with these APIs you find the location and name of places in some category, but you could also get the whole public transport network in GTFS format to work with to create an interesting game about riding buses.

In my option regarding rules, I would be fine if the community or PoV or whoever decides that compo is compo, and no map tiles nor open data is allowed. To use that, join Jam. Or it is classified to be building blocks like fonts, sound fonts etc. and is made allowed. I’m fine with either but would be nice to have it more clearly stated.

How to make a location based game

Posted by
Friday, April 29th, 2016 5:00 pm

You might have noticed my game Shapes Outdoor. It doesn’t use any key, touch or mouse input to control the player. Instead it uses the GPS sensor on your phone/tablet. In this post I will expand a bit on how you can use the GPS in your web game.

In principal, its actually quite simple.

  1. Get hold of the start position. (navigator.geolocation.getCurrentPosition())
  2. Generate shape locations nearby start location.
  3. Continuously monitor player position and calculate the distance to all shapes to get the closest one. When distance is lower than some threshold the player picks it up. Shift the other shapes around a bit to adhere better to the theme. (navigator.geolocation.watchPosition())

So in principal it works like this:

A satellite sends signal to player (getCurrentPosition). Then World generation occurs and red shapes appear around the player. Then watchPosition starts to monitor movement and the player starts to move towards a circle. Finally player reaches the circle and collects it.

The tricky part is to get it to work stable enough in a mobile environment. This includes to handle the cases when browser reject access to the GPS and display an error to the user. But of course also things like how to display the positions of game objects on the screen, how to debug the game etc. Some of these questions I’ll expand on below.


Try Shapes Outdoor – Easy mode

Posted by
Sunday, April 24th, 2016 4:34 pm

In my game you collect shapes in the real world by walking to them with your phone. In the original version it required up to 600 m of walk to get your first shape. Perhaps a bit much.

So I’ve added the option to try my Shapes Outdoor game with shorter walk distance. Your first shape can now be collected within 100 m of walk, and you only need to collect 3 shapes to win the game.

It is still possible to play the original difficulty if you rather like to do so.

To the game


Shapes Outdoor

Posted by
Sunday, April 17th, 2016 4:13 pm

I’m sure many of us got perhaps too many hours indoors? In my game, you get shapes to collect within a 600m radius from your current location. So unless you plan to spoof your GPS-position, you got a game to play while getting out for a walk.

As for shapeshifting, the shapes shift shape when you collect one shape.

This game works best on Android, but can be played on iOS too (no sound). Not tested on Windows Phone. Can be played as a web game as well as by downloading an APK for Android.

To the game


Some walks were performed as part of the development of this game. :-)

Shapes done, shift to do

Posted by
Saturday, April 16th, 2016 10:35 am

Got shapes up and running as well as geolocation and a basic collect shapes game. Next up is to get ‘shift’ into the game. :-)


I’m in

Posted by
Friday, April 15th, 2016 4:26 pm

I’ve got 3 different platform choices:

  • pure JavaScript/HTML5 (like LD33, LD#31 and MiniLD#53)
  • Ionic – and possible toss in some cordova plugins for mobile sensors (like LD#32)
  • Unity/C# – I’m a novice on unity, so I probably won’t go for it.

What I pick depend on the theme and what kind of game I’ll like to develop which I can only decide once I know the theme.

If you liked my Sim Tower inspired game from LD#33, I have improved on it since LD. (save/load, lobby, block building, resizable elevators, better mouse and keyboard input)

Like to play a turn based strategy game?

Posted by
Thursday, April 23rd, 2015 3:17 pm

In Navennni you have one goal; you are going to the Moon. To do so you have to complete a strategy game which is easiest described as a single player mini-version of Settlers of Catan.

My connection to the theme was that I reshuffled the letters to create “Can U Leap To Moon, Navennni?” which is how the game got its name – Navennni. I may have flipped the W upside down too. :-)

This game is the first time I made sound effects and music to a game. It is also my first game using Ionic/Angular and an inline SVG as canvas. It worked out quite nice I think, although screen reader support is quite poor compared to my previous games in LD as I didn’t had time to test that and work around issues.

To the game – Navennni

Screenshot of Navennni game

Trying to make a screen reader compatible game

Posted by
Tuesday, December 9th, 2014 3:13 pm

For some time I have wanted to make a game that works both visually and for people relying on a screen reader that reads out the text. I’m not a screen reader user myself, but since learning some more about how to code interactive websites to work better with screen readers, I wanted to try to make a game with that in mind. In this post I share some details on how I coded my game to make it accessible using a screen reader. I hope it works with other screen readers, but I did only had the time to verify that it works on NVDA with Firefox on Windows. (NVDA is an open source screen reader for Windows)


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