Resource centre for ZX Spectrum games
using Manic Miner and Jet Set Willy game engines
Archive of the
Manic Miner & Jet Set Willy Yahoo! Group
messages
|
|
|
|
|
Message: 6994
Author: rushforthian
Date: 27/12/2016
Subject: Re: Editing diagonal guardians in JSWED
Andrew wrote:
> The 8 guardian-bytes of a DG are used as follows ('%' denotes binary, and the capital letters which follow denote the individual bits from
most significant to least significant):
> Byte 0: %DUUUTTTT
- %D: initial direction (0 left, 1 right)
- %UUU: unused
- %TTTT: guardian-type (5 for a DG that moves '\', 6 for a DG that
moves '/')
most significant to least significant):
> Byte 0: %DUUUTTTT
- %D: initial direction (0 left, 1 right)
- %UUU: unused
- %TTTT: guardian-type (5 for a DG that moves '\', 6 for a DG that
moves '/')
As with horizontal guardians, Bits 5 and 6 of Byte 0 for diagonal guardians (the first two bits labelled 'U' above) are used during run-time to keep track of the guardian's current animation-frame.
Whilst Bits 5 and 6 of Byte 0 are always reset to zero at the start of the game for all the guardians in the original JSW, those bits can in fact be assigned non-zero starting values - and this is the key to achieving true symmetry when laterally inverting guardians (correctly timed with respect to the initialisation of their host rooms).
|
|
|