New flag : NO_SIGHT

[Fris0uman]

Summary

SUMMARY: Content "Adds new flag : NO_SIGHT"

Purpose of change

Tiles with NO_SIGHT flag reduce sight of creatures on it to 1

Describe the solution

Tile with NO_SIGHT flag applies effect_no_sight to creature, effect_no_sight reduces sight to 1.

Describe alternatives you've considered

Additional context

As far as I can tell it works. for player but doesn't for other creatures. But I noticed that effect_in_pit doesn't seem to affect monster sight either.
I'd like input on that if possible.
Also if we don't care about making symmetrical with creatures I guess it could only affect players

[Night-Pryanik]

What types of terrain should produce this effect?

[Fris0uman]

I plan on adding it, at least, to Pillow Fort and Dumpster after the merge of #27620
And maybe also to Dresser. The idea is that in combination with HIDE_PLACE some furniture/terrain can be made into hiding places, you get in and you're hidden and can't see out without peeking out of it.
So any kind of terrain you can "get in"

[jbytheway]

The line breaks here are not sensibly placed.

[Fris0uman]

I used the astyle extension on Visual studio and the settings from code_style.md
But I can re arrange things if needed

[Fris0uman]

What would be sensibles line break ? Keeping !has_flag( MF_AQUATIC ) and !digging() on the same line ?

[jbytheway]

I'd suggest either

if( !can_see() || has_effect( effect_no_sight ) ||
    ( underwater && !has_flag( MF_SWIMS ) && !has_flag( MF_AQUATIC ) && !digging() ) ) {

or

bool swimming = has_flag( MF_SWIMS ) || has_flag( MF_AQUATIC );
if( !can_see() || has_effect( effect_no_sight ) ||
    ( underwater && !swimming && !digging() ) ) {

[Fris0uman]

Done. I used the first suggestion.

[Fris0uman]

But maybe I should have edited can_see() directly ?

[jbytheway]

I haven't tested, but this doesn't seem right. It looks like you're adding a 1-turn effect on moving to a location with NO_SIGHT, but won't that wear off after 1 turn if the NPC remains there? An effect doesn't seem like the right approach for this feature. Also, it would be unfortunate to need npc-specific code to make it work (as opposed to code for all creatures or at least all player objects (which currently includes npc).

[Fris0uman]

No It uses the same system as "bouldering" effect : it adds a permanent effect and removes it when the creature moves out of the tile. I think it's pretty ugly but it's the only way I found.
As far as I understood the code applying effect from terrain to creature is spread across monstermove.cpp, npcmove.cpp and game.cpp
Basically NO_SIGHT works like UNSTABLE.
But maybe UNSTABLE flag could be re worked as well.

[kevingranade]

This pull request has been mentioned on Cataclysm: Dark Days Ahead. There might be relevant details there:

https://discourse.cataclysmdda.org/t/creature-sight-range/18579/1

[Fris0uman]

After more testing it appears that it works for player, monster and NPCs. I was getting false negative before because monster spawning directly on the tile don't get the effect, they need to walk on the tile to get it.