Another thing that I meant to point out last night, but forgot: the only moving elements that aren’t prone to the ‘Delayed Attribute Effect’ are Ropes, because they don’t update the colour-attribute of the cells through which they pass (they are always rendered in the pre-defined INK colour of their host cells).
Anyway, here’s one more example of the ‘Delayed Attribute Update’ effect – please see the attached screenshot, taken just after Willy has dropped into ‘Entrance to Hades’. (This one didn’t require any messing around with the room’s Air attributes to illustrate the point – it is a very prominent effect in the original JSW, based on the original settings for this room.)
Once the graphic bytes representing Willy’s legs have been drawn to the screen file - at a point in time when he has just fallen past a cell-row boundary - there is a relatively long delay before his legs are rendered in the customary White. That is because the program has to draw the rest of the graphic bytes for the upper half of the playing area, and then the graphic bytes for the entire lower half of the playing area, before the Main Loop starts the task of refreshing the attribute file row-by-row.
The cumulative effect of that long delay, and the visually-striking contrast between the three colours involved (Green/Yellow/White), means that the ‘Green Legs’ effect is very pronounced. Although I think it becomes less pronounced, the further Willy falls down the screen.
(Actually, typing this out has got me thinking that perhaps the Green INK for the Air cells in ‘Entrance to Hades’ was deliberately chosen, in order to prevent part of the ‘Demon Head’ guardian from briefly ‘disappearing’ as it moves up and down across cell-row boundaries? That is a less-noticeable element of the ‘Delayed Attribute Effect’ in rooms where the Air INK and PAPER settings are the same – the leading pixels are rendered ‘invisibly’ for a brief moment as an entity advances into the next cell, before the attributes are refreshed - perhaps this is more noticeable on a non-Black screen?)
Edited by IRF, 03 April 2017 - 12:44 PM.