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using Manic Miner and Jet Set Willy game engines
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Message: 7135
Author: rushforthian
Date: 23/08/2017
Subject: Re: JSWED 2.3.1: Andrew's comments (Chapters 14 to 17)
Andrew wrote:
> And I know there are experimental guardian-types such as #58 (Lift) and #78 (Droplet), not currently > supported by JSWED. And #68 and #D8 (what are these?), as mentioned in Section A.6.
Looking at the code, Guardian type #68 seems to be a harmless guardian - it is drawn without colliding with Willy (I think it should be drawn in its entirety - unlike switches which, when Willy touches them, are only drawn as far as the graphical byte which detect the collision with his sprite). It shares common code with the Lift guardian (type #58) - John Elliott's experimental Lifts would appear to be non-fatal to Willy (unlike Broadsoft Lifts) - but the Lift code calls the Type #68 Drawing code as a subroutine before proceeding to do the Lifty stuff.
A guardian of type #D8 appears to be a variation on Triggers, the only difference being that it overwrites Bytes 4-7 of the subsequent guardian (and then cancels itself out) as per usual, but it doesn't edit the subsequent guardian's Byte 0. Type #D8 is used in the JSW64 conversion of Manic Miner in the two Kong Beast caverns, presumably to prevent the magenta 'rolling rock' horizontal guardian from suddenly changing animation-frame once the collapsing wall has fully opened up. N.B. Even though the Trigger doesn't actually change the guardian type in this case, the current animation-frame is stored within the same byte as the guardian type. So if a regular Trigger were to be used, then this could cause the 'rolling rock' to jerk forwards (or backwards) suddenly at the moment that the rock's definition is adjusted.
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