Corona Geek #122 – Using Coroutines in Lua and Creating 2D Shadows

Corona Geek #122 – Using Coroutines in Lua and Creating 2D Shadows

Corona Geek

During this week’s Hangout, Corona Developer, Steven Johnson (aka, Star Crunch in the forums) introduced us to the concept of time slicing using coroutines in Lua. Steven presented a collection of lua coroutine code examples to show how coroutines can be used to stop and start the execution of code and how to reduce the amount of code needed to work with timers.

René Aye from PyroPixel also showed us how to create 2D shadow effects on angular, round, and complex shapes using his 2D shadow system. René showed several 2d shadow demos including one using Corona’s built-in physics engine and one with multiple 2D shadows and draggable light sources. The effects are amazing and will add a whole new dimension to your games.

Ship Just One More App Before 2015

Want to get that unfinished app off your hard drive and into the app store? Then participate in this year’s first annual Ship Jam and win some prizes. Community members, Laura Tallardy and Eric Kinkead are hosting the jam. Check out the Ship Jam website for full details.

December’s Geek Games Winner!

For December, we played City Birds and Vritra for a chance to win two $50 gift cards.  This month’s high score winner of both gift cards is Greg Pugh from GPAnimations.

While this month’s competition is over, you can still play both gamess and post your high score on the Corona Geek Facebook wall. Can you beat Greg’s score?

Replay Last Week’s Show


  • Time is almost up! Just 2 more days to use coupon code CoronaGeek and save 20% at checkout when buying Corona SDK books from Burton’s Media Group. The coupon code expires on January 1st. Get it before it’s gone!


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Charles McKeever

Charles McKeever is a life long computer geek who enjoys exploring technologies to understand how they work, how they can be smashed together, and how they can be used to fuel entrepreneurial endeavors.

  • John
    Posted at 17:46h, 29 December

    I think there is a folder “utils” missing from the repository.

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