log in | register | forums


User accounts
Register new account
Forgot password
Forum stats
List of members
Search the forums

Advanced search
Recent discussions
- Wakefield 2022 Show Report (News:1)
- Wakefield show 2022 in pictures (News:)
- R-Comp releases Messenger Pro 9 for Wakefield Show (News:)
- RISC OS Bits at Wakefield (News:)
- General discussion at Rougol May meeting (News:)
- Wakefield Super Prize Draw (News:)
- Certificate error (Gen:2)
- Wakefield-in-Bradford Show 2022 takes place this month (News:1)
- AMCS free versions are live! (Gen:29)
- Archive gets a new edition and a new website (News:)
Related articles
- Rougol April meeting report
- Rougol March meeting report -30 years of GAG News
- Rougol January Talk - Recoding the Classics with Jeroen Vermeulen
- Rougol December perspective
- Rougol November talk - RISC OS Pyromaniac update
- Monday night is Rougol September talk on RISC OS distributions
- Rougol August meeting is an award-winning event
- Rougol July talk
- July Rougol meeting goes hybrid
- Rougol June Talk - RISC OS in those StrongARM days with Mike Stephens
Latest postings RSS Feeds
RSS 2.0 | 1.0 | 0.9
Atom 0.3
Misc RDF | CDF
Site Search
Article archives
Acorn Arcade forums: News and features: Rougol Feb meeting report - writing games with Terry Swanborough

Rougol Feb meeting report - writing games with Terry Swanborough

Posted by Mark Stephens on 21:40, 21/2/2022 |
The February Rougol was again a hybrid in person / Zoom event (about 25 people in total), with the speaker present in the pub on this occasion. Those at the pub enjoyed some excellent food, drink and chat so well worth showing up if you can.

Terry spent a lot of lockdown writing some versions of classic arcade games for RISC OS. He did a lot of experimentation with things like the vsync, tricks to speed up the display. The talk is well watching in detail for ideas, tips and those OS calls. Here are my notes...
Orginally, Terry wrote some games in C but was curious to see if Basic would be fast enough. Turns out it is, especially using some clever tricks.
Stargate uses triple buffer. Talked about drawing to sprite for speed but not mode independent. Tony did a lot of experimentation with full screen and desktop plotting and how to get it fast and flicker-free.
Game timing is independent of vsync speed and uses Arm club timer module. Graphics loop adapts amount of movement for slower machines. Move in larger increments on slower refresh.
The games uses a lot of plotting to sprite which speeds up both reading and writing data.
Plotting to sprite also makes it easier to read pixel values (it is local memory).
Games also run in desktop mode
Uses rdsp and amplayer for sound and music
Nice extended demos of after all that theory showing stargate and munchy in action and adapting their speed so same on all machines if possible
Pac-Man games actually needs complex code to handle movement of monsters.
Basic great for creating mazes
Decrypt made use of Artworks features for development like export as bitmap in mode. Also used Changefsi and Paint to create.
Packman uses location based collision detection. Stargate uses unique colour in force field for speed. Basic fast enough to handle this as reading values from local memory.
Currently writing a space invaders game which looks really good!
Demos will be on website with code for anyone to tinker with.
Thanks for Bryan (as always) for organising and ROUGOL will be back in a month's time...
Rougol website
Log in to comment on this article

Acorn Arcade forums: News and features: Rougol Feb meeting report - writing games with Terry Swanborough