Friday, 22 October 2010

Bumper Update

Blog Updates have been quite scarce of late, as they tend to become a lower priority when development time gets squeezed. Yet progress continues to be made at a reasonable pace.

XNA v4.0

The latest version of the XNA has some changes to enable Microsoft to add Windows Phone 7 support. Most importantly, it splits the framework up between two profiles - 'Reach' (the lesser) and 'HiDef' (the greater). Fortunately, XAGE's current functionality fits neatly within the confines of the Reach profile, meaning it will continue to support Windows, Xbox as well as WP7.

There are also a number of changes which, to paraphrase Microsoft's Shawn Hargreaves, 'break it good'. Most of these have already been worked around, although there are some issues particularly around sprite rendering & IO. What further complicates matters is that the three open source libraries upon which XAGE depends to allow it to target other platforms are all still based on XNA 3.1 - it's possible to work around this whilst they are updated, though it means the engine code will be further muddied with additional pre-compiler directives. Until further notice, it's safe to consider all platforms officially broken until they're all fixed & re-tested.

Supported Platforms & Associated Costs

The website is also a little neglected and out of date, which has caused some confusion regarding the current status of platform support. Until now most of this information has been held loosely in my head, so hopefully this clarifies matters somewhat:


Where each image represents a required license (correct at time of writing):
  • Photobucket XAGE (£?): Required for any commercial games. Freeware/non-profit games will not require a license.
  • Photobucket Microsoft App Hub Membership ($99 annually): Required for any games released on Xbox360 and Windows Phone 7.
  • Photobucket MonoTouch / MonoDroid ($399 each, one-off payment with 1 year of updates): Required to deploy XAGE games (based on Mono) for iOS and Android platforms respectively.
  • Photobucket Apple iOS Developer Program ($99 annually): Required in order to deploy any game to the iPhone, iPad and iPod Touch.
To Summarise:
  • It is completely free to create freeware XAGE games for Windows & Silverlight (in the future this will likely also include Linux & Mac OS X).
  • It is not possible to create freeware Xbox360 games due to Microsoft's pricing model.
  • The iOS platforms are the most expensive for commercial XAGE games, given they require three licenses (XAGE, Apple, MonoTouch) not to mention any additional hardware costs.
List Support

The most recent addition to the XAGE engine is basic support for Lists. The decision was made as they offer greater flexibility than standard arrays, and will automatically grow to fit the desired size. AGS Arrays will automatically converted as XAGE Lists.

Alongside this, basic string manipulation is in place (long overdue as absolutely required, not least for softcoded LucasArts style Verb GUIs). XAGE will understand C-style formatted strings and concatenate them as required.

As a result of this new data structure, in a stroke '!' went from being quite broken to fully playable from start to end. All of the puzzles now work (including that pesky DNA phone) and besides a few wonky quirks it's starting to look pretty good. As usual, the Editor itself is incomplete and I'll get around to this when needed. In the meantime there's still a few things remaining in order to complete '!':
  • Three remaining AGS Functions need to be mapped (Character.SayAt, SetMusicVolume, SetMusicRepeat).
  • Fix some animation oddities.
  • Fix some GUI issues (GUI background colours)
  • Fix the load/save mechanism as per of new Xna Framework version.
  • Resolve music seek issue.