fix #73907 Stop Flip Flopping mutations in Alpha stomach chain

[Kamejeir]

Summary

Bugfixes "Flip-flopping in acquisition of Intestinal Fortitude"

Purpose of change

bugfix #73907

Describe the solution

Weak Stomach now leads to Nausea, that itself turns into Vomitous.

Intestinal Fortitude has its different prereqs replaced with Weak Stomach and Vomitous, the two of which are set to change into Intestinal Fortitude.

Removes Robust Genetics from Alpha. Alpha should be a jealous category.

Describe alternatives you've considered

Testing

It only go in one direction, and through a couple runs of mutating Rat, never observed Vomitous turning into Nausea.

Weak Stomach, Nausea and Vomitous successfully disappear after acquiring Intestinal Fortitude.

Additional context

[Kamejeir]

Tests are failing because breach power is too high. I could shove something else around, or edit the test to make Alpha slightly easier to get. I don't know which to choose.

[Kamejeir]

Now after Venera telling me that I am not to change the test, the other option has me wondering what to even do. I haven't ever gotten involved with the balance of Alpha. My best and only guess is to move Deterioration to post-thresh.

[Maleclypse]

Do not merge until I can look at this.

[Maleclypse]

Deterioration to post thresh is not going to work. I’ll look at some options. I think in this specific instance Venera may be wrong about the test because it’s the alpha category and if he isn’t wrong it should be a positive mutation that moves to post thresh.

[Kamejeir]

Actually, looking back, it is extremely wacky that the test succeeded. The total amount of mutations potentially available to breach didn't change (Weakening just stayed, when it would have otherwise turned into Deterioration, which would have resulted in no point where, there less Alpha mutations to potentially make it harder to go post-threshold). It makes me think the test is unreliable and should be changed.

[Kamejeir]

These ones could use a 61 instead of 60 in case it is determined that the test should be changed rather than editing Alpha stuff.

Cataclysm-DDA/tests/mutation_test.cpp

Line 213 in 8b1645f

// Alpha threshold is intentionally meant to be harder to breach, so the permitted range is 35-60

Cataclysm-DDA/tests/mutation_test.cpp

Lines 243 to 246 in 8b1645f

	THEN( "Alpha Threshold breach power is between 35 and 60" ) {
	INFO( "MUTATIONS: " << get_mutations_as_string( dummy ) );
	CHECK( breach_chance >= 35 );
	CHECK( breach_chance <= 60 );

[Kamejeir]

btw are you on github via the site or..? edited the first message after your actions a lot, it changed meaning pretty drastically, dunno if edits are re-sent as a new message

[Maleclypse]

btw are you on github via the site or..? edited the first message after your actions a lot, it changed meaning pretty drastically, dunno if edits are re-sent as a new message

They aren’t sent as new messages. No worries. So the issue with the test is that alpha has a unique test in the larger threshbreak test because it has fewer mutation than you can breach with otherwise. It’s the smallest tree. The note on the test is wrong but basically because it’s so small you have to change the threshbreach chance if you add a mutation or else it will be unnaturally easy to become thresh alpha

[Kamejeir]

Then it appears as though we have to move an independent mutation (one that does not change to anything else / is a parent that something else changes into, and thus actually makes a difference for breach power) post-threshold.
The three choices that fits the bill are as follows:

• Weak Scent (starting trait quality would probably have to go)
• Picky Eater (ditto for above, as well as this believably imo being what an "average dude" could have)
• Highly Vain
  I chose these ones because they are uniquely available to Alpha, letting us remove a mutation pre-threshold to counteract the part of adding one (with Weak Stomach now coexisting with Nausea).

[Kamejeir]

Well, color me impressed. I had failed to understand that it was about points within the mutations, not the number of mutations.

[Kamejeir]

Oops, too hasty a judgment. Well, that was a failure.

[Maleclypse]

Oops, too hasty a judgment. Well, that was a failure.

Yeah I expected that would likely be a failure because I was pretty sure negatives didn't count by points. Other people seemed to think this might be a way to impact points by adjusting the positives again, not sure that the points the test is counting correlate.

[Maleclypse]

 if( !have_upgrade && !mdata.flags.count( json_flag_NON_THRESH ) ) {
            // ... find the mutations distance from normalcy...
            int mut_height = mutation_height( mut );
            // ... and for each category it falls in...
            for( const mutation_category_id &cat : mdata.category ) {
                // ... add the height and a constant value
                mutation_category_level[cat] += mut_height + 2;

So by making the lead to instead of change to you've added one to the height of the stomach branch. So none of these changes I've been trying have a chance of working. I'm going to make a PR to remove the special treatment for Alpha threshbreach and after that is merged this will pass.