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Message: 6899

Author: ian.rushforth

Date: 05/08/2016

Subject: Re: Mirror MM/JSW / MM - JSW Conversions

 

Daniel said:

> In "ylliW teS teJ" I noticed that there are some things which are

> not inverted, such as ropes or arrows (or so it seems, at least).
> This creates some differences with the original in the gameplay. I
> had a nasty surprise when I discovered that you cannot climb down
> from "rewoT hctaW" ("Watch Tower"), because the rope in the room
> below keeps throwing you upwards, back into "rewoT hctaW". So I
> couldn't take what I consider to be the most effective route
> around JSW (climbing down from "Watch Tower" after collecting the
> items and later exiting upwards in "Rescue Esmerelda"), and I had
> to use the second most efficient route, which involved re-
> recording most of the game!

Andrew said:

> Ropes start at a different place in the swing when going right

initially as opposed to left. I should look into this further one day.

I was thinking about that.  In order to create a Rope with true symmetry, I believe you need to:

(a) set Bits 7 of Byte 0 and Byte 1 of the Rope's Definition Bytes (so in original JSW, instead of having values of #03 and #22 at #A008-A009, you would have #83 and #A2 respectively); and

(b) change the value of #92B5 in the rope-drawing code from #80 to #01 (i.e. the right-most bit set for the 0th segment of the Rope, rather than the left-most bit).

The latter value is hard-wired into the game engine.  I tried inserting the appropriate value into Byte 5 of the Rope Definition at #A00D - which would open up the possibility of different Rope Classes for which the top segment occupies a different position within its cell-column - but it made the top of the Rope 'jiggle' from side-to-side (I think because the 'copy' of Byte 5 of the Rope's Definition in the Buffer at #81X5 or #81XD is subject to constant updating as the Rope is drawn/animated).

 

 

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