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Re: Sprite Loading / Plotting SWIs and lotting in any colour depth

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In article <4e8b354b$0$30777$ba4acef3@reader.news.orange.fr>,
   Rick Murray <heyrickmail-usenet@yahoo.co.uk> wrote:
> On 04/10/2011 12:36, Martin Wuerthner wrote:
> > It is a mystery to me why there is no "plot this sprite to the screen"
> > SWI call in RISC OS.

Seconded.

> But, that said, it isn't that hard to built a ColourTrans table and plot 
> to screen.

No, it is not that simple.

First of all, just getting your head around those concepts is hard initially.

Secondly, the documentation is spread over various parts of the PRMs. 

Thirdly, you will still get the wrong answer, because you've not created
your transformation matrix to cope with differing eigen values of different
screen modes. This is a whole extra can of worms.

So a true, mode-independent sprite plotting routine actually takes quite a
bit of crafting, testing and more than two SWI calls. And of course if
you're writing a Wimp application, you then need to be watching for mode
changes and re-calculating various things to cope with changes to the
characteristics of the mode. It all ends up quite complicated.

It can take _days_ (especially if you're fairly new to programming on RISC
OS) of reading all sorts of bits of the PRMs, head-scratching, trying to
comprehend arcane terminology and experimentation simply to plot a f*ing
sprite on the screen. Utter, utter madness.

Thanks,

Steve

-- 
Steve Revill @ Home
Note: All opinions expressed herein are my own.

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Sprite Loading / Plotting SWIs and lotting in any colour depth Michael <michaelremerton@gmail.com> - 2011-10-02 04:04 -0700
  Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Michael <michaelremerton@gmail.com> - 2011-10-02 04:15 -0700
    Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Michael <michaelremerton@gmail.com> - 2011-10-03 12:09 -0700
      Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Alex Macfarlane Smith <nospam@archifishal.co.uk> - 2011-10-03 20:44 +0100
        Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Michael <michaelremerton@gmail.com> - 2011-10-03 13:24 -0700
          Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Martin Bazley <martin.bazley@blueyonder.co.uk> - 2011-10-03 21:45 +0100
        Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Martin Wuerthner <spamtrap@mw-software.com> - 2011-10-04 12:36 +0200
          Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Rick Murray <heyrickmail-usenet@yahoo.co.uk> - 2011-10-04 18:33 +0200
            Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Martin Wuerthner <spamtrap@mw-software.com> - 2011-10-04 20:25 +0200
            Re: Sprite Loading / Plotting SWIs and lotting in any colour depth "Ste (news)" <steve@revi11.plus.com> - 2011-11-02 00:25 +0000
              Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Rick Murray <heyrickmail-usenet@yahoo.co.uk> - 2011-11-02 19:05 +0100
                Re: Sprite Loading / Plotting SWIs and lotting in any colour depth druck <news@druck.freeuk.com> - 2011-11-02 21:21 +0000
      Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Martin Bazley <martin.bazley@blueyonder.co.uk> - 2011-10-03 21:41 +0100
        Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Michael <michaelremerton@gmail.com> - 2011-10-03 18:22 -0700
          Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Rick Murray <heyrickmail-usenet@yahoo.co.uk> - 2011-10-04 20:07 +0200
    Re: Sprite Loading / Plotting SWIs and lotting in any colour depth chrisbazley@bigfoot.com - 2011-10-06 21:03 -0700
      Re: Sprite Loading / Plotting SWIs and lotting in any colour depth Rick Murray <heyrickmail-usenet@yahoo.co.uk> - 2011-10-07 07:04 +0200

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