Online RISC OS colour converter
13/09/2017 10:19
Hello, For many years I didn't really understand the difference between the various colour formats used in 256 colour screen modes. (e.g. why can't the value returned by ColourTrans_ReturnGCOL be used with BASIC's GCOL command?) Then, I found a bug in ColourTrans related to 256 colour modes with a fully-definable palette, had an argument with Gerph about it, and during this period wrote several BASIC programs to test GCOLs and took a lot of notes.

Now, I present an online converter written in JavaScript that can be used to convert between the following colour formats: Colour number, separate GCOL and TINT, packed GCOL, Wimp and HTML colours. Alongside, I have published some of my notes about each format and its usage.

Colours can be entered in decimal format (except HTML, which must be hexadecimal) or by clicking on checkboxes to set a binary pattern.

http://cs99cjb.pwp.blueyonder.co.uk/convert.html -- Chris Bazley

Source is Usenet: comp.sys.acorn.programmer
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Answer score: 5
13/09/2017 10:19 - chrisbazley@bigfoot.com wrote: Is this a things-never-to-do list or a things-I-wish-I-hadn't-done list? Alan -- RISC OS - you know it makes cents

Source is Usenet: comp.sys.acorn.programmer
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Answer score: 5
13/09/2017 10:19 - Alan Wrigley <spamhater@keepyourfilthyspamtoyourself.co.uk> wrote: And ten seconds after writing that post I discovered one of my own: Don't spend an afternoon taking photographs (and spending money on petrol) when the memory card is still in the computer after uploading the morning's pics.

Bah.

Alan -- RISC OS - you know it makes cents

Source is Usenet: comp.sys.acorn.programmer
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Answer score: 5
13/09/2017 10:19 - On Apr 23, 2:12=A0am, chrisbaz...@bigfoot.com wrote: Be fair... we had /lots/ of arguments about the colour system :-) between what we understood (which differed as we understood it more), what the system did (which differed as we fixed things), and what the PRMs said (which generally wasn't to bad but sometimes differed from reality).

I'm pretty certain (well, reasonable certain) that we fixed the vast bulk of the issues with 256 colour modes when fully defined and when greyscale compared to the old-style 256 colour modes. If there was anything lingering then I'm sure it got sorted later.

It's amusing to me quite how broken fully-defined modes really were, from simply getting the wrong results through to crashing.

Hmm. My list of ThingsNotToDo only contains a single reference to the colour system, for pre-S3 do not: * Use ColourTrans to render deep sprites Probably the stuff we found was non-fatal so not worthy of going in there.

Ah, good memories...

-- Gerph.


Source is Usenet: comp.sys.acorn.programmer
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Answer score: 5
13/09/2017 10:19 - On Apr 23, 4:40=A0pm, Gerph <ge...@gerph.org> wrote: I've never heard of a things-not-to-do list before. It sounds like a useful idea.

* Fall in love.

* Reverse into bollards.

* Go out without your house keys.

* Mix signed and unsigned types in expressions.

* Confuse solipsism with solecism, for fear of malapropism.

* Use MOVS PC,R14 to return from a software vector claimant in a 32 bit mode.

* Use BL with interrupts enabled in IRQ mode.

* Pass go.

* Collect $326.10.

* (add your own) The list may be endless! -- Chris Bazley

Source is Usenet: comp.sys.acorn.programmer
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