unfamiliar code from LIST command
HelenAA
🖼️ 10 images Surveyor
I'm having difficulties removing 2 symbols so I did a LIST command and I found myself looking at a list of what I think (internally) as 'definitions' but as there's no way that I know of selecting the text in the blue pop-up window, I copied the first 'definition' and paste it here.
Sheet: BACKGROUND CITY
Apply filter entity color 0 (black) layer 0 (MERGE)
line style 0 (Solid) fill style 0 (Hollow)
line width 0” tag # pen :0.00 2nd color 0
MODE 1 (AM_START)
MODE 2 (AM_STOP. )
It's the MODE part I have never encountered before. Sometimes it is (AM_START. AM_STOP) but that seems to be MODE 3 before the brackets.
Would someone relieve my curiosity?
Comments
The effects system uses those entities to control what happens when during the rendering of the drawing to the screen. You will see them sometimes if you LIST everything on a sheet (that is, use a non-visual "select all" kind of modifier) or use the LISTDWG command to list everything in the drawing database. The number after MODE is the bitfield associated with the labels (1 = AM_START, 2=AM_STOP, 3=AM_START+AM_STOP).
The sequence of APPLY entities in the whole drawing should read AM_BEGIN, {AM_START/AM_STOP once per sheet}, AM_END, and finally AM_DONE. Sometimes the per-sheet sequence will have both AM_START and AM_STOP flags in a single record and sometimes (when there is a sheet to be skipped) the AM_START/AM_STOP states will be separated.
I hope your curiosity is relieved and not cowering in fear that explanation.
I'm not cowering at all - I am just fascinated
Those entities are the main reason why you should never use the SHEETS dialog to manage the sheets in your drawing, but rather always use the EFFECTS dialog for that purpose. The SHEETS dialog doesn't know about APPLY entities and the need to manage them in the drawing, so inserting sheets and deleting sheets may result in the effects not quite working correctly until the next time that the sheets in the EFFECTS dialog changes or until the next time the drawing is reloaded. You're unlikely to see the SHEETS dialog, but there are (or were at one point) paths that can get there from places that ask you to pick a sheet.
@jslayton You just blew my mind. I don't think I understand the reason. Would you please elaborate on this? What's the difference between using EFFECTS versus just refreshing the display? I'm missing something.
Thanks.
]to my knowledge I haven't gone near any SHEETS dialogue - but with my cerebral palsy hands doing their own things over recent weeks in the heat we've had in the southern UK, anything is possible. 😁 Thanks for your warning though.
The effects system relies on custom entities to sequence the operations for rendering effects. When effects are turned on or off, those entities are added or removed from the drawing (it also happens at some other times, but not during regular display of the drawing) to construct the effects rendering state machine. When the custom entities are not in the drawing, no effects will be visible because the effects renderer is never initialized or updated. When the custom entities are in place, the state machine operates normally. If some of the custom entities are removed but not others (as can happen if the SHEETS dialog is used to delete a sheet) then the effects rendering will be not as expected (how unexpected will depend on which entities were removed).
The EFFECTS dialog is a superset of the SHEETS dialog and knows about how to construct the effects state machine. The SHEETS dialog doesn't know about the state machine at all. This happened because the effects subsystem is completely contained in the Effects.dll XP, while SHEETS is a core feature of the underlying CAD engine.