Popcorn

Popcorn is a library to help you write RISC OS games in C. It provides fast sprite plotting, management of object tables, collision detection, and resource management.

Popcorn was originally written by Matthew Bloch in conjuction with a series of articles he wrote for Acorn User. Matthew has since moved on to other pastimes, and I (Rik Griffin) have been tinkering with Popcorn from time to time since then.

New features I've added recently:

• 32 bit sprite plotting with alpha blending
• Hardware acceleration on Iyonix
• Improved and tidied the API

Full source code is provided, and the licence allows you to use the source or object code for any purpose you wish.

I've put together a very simple tutorial on how to use Popcorn's basic features - download it here. The tutorial describes how to write a "Pong" game.

For a slightly more complex example of what Popcorn can do, see Hive - source code is provided.

Download Popcorn (dated 8 June 2007). Size: 102k

Download a StrongHelp manual detailling the Popcorn API (dated 8 June 2007). Size: 12k

NOTE: Popcorn uses several modules to access enhanced hardware features which any application using it will need to load - although for most of the features there's a slower software fallback available. These modules are:

• Application accelerator - this provides access to a fast memory copying feature in the Iyonix's CPU. Popcorn uses this for fast backdrop plotting on the Iyonix. Not available on other platforms.
• HAL Timer - Provides a high resolution hardware independent timer. Without this module, Popcorn's Timer functions will not work.
• HAL26 - This is required if using the HALTimer module on a platform that doesn't have HAL support in the OS - in other words non-RISC OS 5 platforms.
• Intel DMA - provides DMA transfers between main memory and a PCI device. Used to accelerate screen access, only on Iyonix hardware.