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- Help file for To24bpp
- ——————————————————————
-
- This application is copyright Liam Gretton.
-
- This is a simple utility with a cumbersome name for users who
- don't have RISC OS 3.5. It requires ChangeFSI 0.95 or greater.
- Acorn's Help application is supported.
-
- It may run on Risc OS 2 machines... but this hasn't been tested.
-
- If you are running this on a Risc PC, then why? Also, if you have
- Computer Concepts' graphics filters (currently available for
- TIFF, JPEG, PhotoCD and Clear files), then you don't need this
- program for those file formats.
-
- To24bpp is primarily for users of ArtWorks or Impression Style
- or Publisher who wish to convert a 24 bit foreign file format to
- one of the new 16 or 24 bit sprite formats. ChangeFSI 0.95 can
- do this, but because RISC OS 3.1 doesn't support them,
- ChangeFSI falls over if you try to do the conversion in the
- desktop. From the command line, though, ChangeFSI will
- successfully output a 24 bit sprite, but it's a pain in the neck.
- To24bpp is therefore a simple desktop front-end for this
- particular feature of ChangeFSI.
-
- To use the program, double-click on the !To24bpp icon, and it
- will install itself on the iconbar. You must ensure that the
- filer has 'seen' ChangeFSI beforehand. The program is controlled
- through its menu which looks like this...
-
- +----------+
- | Info | Leads to a standard info box.
- | |
- | Image > | Leads to a dialogue box giving some information
- | | about the file.
- | Save > | Leads to a save box.
- | |
- | Quit | Quits the application.
- +----------+
-
- The Image and Save items are greyed out until a file has been
- dropped. The save box has four icons allowing you to select
- from a 256 grey-level sprite, or a new format 16- or 24-bit
- sprite. If you have dropped GIF file onto To24bpp, there is an
- option to save a 256 colour sprite which has the same palette as
- the original. This obviously uses half the space of a 16-bit
- sprite, but with no loss of colour information. This conversion
- is not done by ChangeFSI, but by the 'gif2spr' utility, written
- by Simon Truss (further thanks to Simon for sending me the
- latest version of gif2spr). The file g2sHelp in the To24bpp's
- Resources directory gives more information about gif2spr.
-
- Dragging the sprite icon to a directory display or another
- application starts the conversion and saves the sprite. Filling
- in the writable field and clicking on the 'save' button also
- starts the process. Clicking on the 'cancel' button closes the
- menu and resets To24bpp to its virgin state.
-
- For simplicity, none of the more advanced features of ChangeFSI
- are supported. However, once you've got your image into ArtWorks
- or Impression, you can flip it, rotate it and rescale it to your
- heart's content.
-
- Only some filetypes are rejected by To24bpp, as ChangeFSI
- examines the contents of files if it doesn't recognise them
- immediately.
-
- Sometimes if you try to save the sprite to an application, the
- conversion is carried out ok, but there's not enough memory for
- the app to load the sprite afterwards (this is most likely with
- JPEGs). You may find your converted sprite in Wimp$Scrap from
- where it can be recovered.
-
- Not all errors reported are from To24bpp. Any errors from
- ChangeFSI are also reported (they're usually due to lack of
- memory). gif2spr's output is suppressed, so it will not report
- any errors. If it has any problems, you will find that your
- sprite is not saved. This does not cause To24bpp to crash
- however.
-
- Advanced options...
- You can alter the !Run file to tweak the program's operation.
- There are two variables used by ChangeFSI itself and one used by
- To24bpp. These are:
-
- ChangeFSI$Cache Used when converting JPEGs. If this is
- larger than the JPEG file size, conversion
- is considerably faster. The default is 128k.
- In practice, I have found that this must be
- set to a value large enough to accomodate
- the file, as ChangeFSI doesn't seem to be
- able to start up the djpeg routines from
- within To24bpp.
-
- ChangeFSI$PCDIndex Indicates which PhotoCD file is to be
- converted from the five versions available.
- Valid values range from 1 to 5. The default
- is 3 (base). I haven't been able to test
- PhotoCD conversion, and it may well fall
- over unless you have the support module
- which comes with Acorn's PhotoView.
-
- ChangeFSI$Max The maximum size of the output sprite held
- in memory before being output to disc. This
- is useful when very large files are to be
- converted. The default is 512k.
-
- These variables can be changed at any time. For example, if you
- find that you don't have enough memory to convert a file, enter
- 'Set ChangeFSI$Max 100k' (or similar) at the command line and try
- saving again.
-
- For more information on ChangeFSI$Cache and ChangeFSI$PCDIndex,
- refer to the file 'FSIinfo' in the ChangeFSI directory.
- ChangeFSI$Max allows To24bpp to use ChangeFSI's 'max' command.
- More details about this are also in the FSIinfo file.
-
-
-
- Thanks are due to Jon Ribbens of DoggySoft for his excellent
- WimpExt module, Alex Petrov of Moscow for his MenuUtils module
- and Simon Truss for his gif2spr utility. The templates were
- created using Dick Alstein’s TemplEd. Oh yeah, and thanks to
- whomever wrote ChangeFSI, too.
-
- If you find this at all useful, or if you find any bugs, or have
- any suggestions for improvement, please let me know!
-
- Liam Gretton
- ljg2@leicester.ac.uk
-
- 62 Berners Street ...or... 18 Lyndhurst Avenue
- Leicester LE2 0AF River
- (until July 1995) Dover
- Kent CT17 0LY
-
- NOW FOR THE MUNDANE LEGAL BIT
- —————————————————————————————
-
- To24bpp is FREEWARE and I retain the copyright. It may be freely
- copied and distributed provided that all the original files are
- left intact. If you think it needs improving, don't distribute
- versions with your own adjustments - mail me and I'll fix the
- problem. PD libraries may distribute To24bpp for a nominal (ie
- minimal) fee to cover costs. I'm fed up with certain magazines
- and user groups selling 800k discs full of FREE software for
- £2.00 or more. I take no responsibility for any loss of data,
- life or sanity as a result of using To24bpp. If To24bpp trashes
- your hard disc and blows up your monitor... well, I apologise,
- but don't say I didn't warn you.
-
- The MenuUtils module is © Alex Petrov:
- Flat 107, Building 1
- 29 Kavkazsky Boulevard
- Moscow
- 115541
- RUSSIA
-
- APetrov@misis.msk.su
- APetrov@arm.msk.su
-
- The WimpExt module is © Jon Ribbens of DoggySoft:
- DoggySoft
- Furzefield House
- Furzefield Road
- Beaconsfield
- Bucks.
- HP9 1PQ
-
- wxii@doggysft.demon.co.uk
-
- The gif2spr utility is © Simon Truss:
- 11 Fairfield Crescent
- Fairfield
- Liverpool L6 8PH
-
- simon@bigblue.demon.co.uk
- ulsmt@csc.liv.ac.uk
-
- The MsgTrans module is presumably © Acorn, and if I shouldn't be
- distributing it with this, sorry.