Trench height

[Keshash]

Additions

Describe new functionality added by your code, e.g.

• adds a mod extension to manage height offsets of buildings that pawns stand on.
• gives pawns on water terrain a height offset. -0.75 height (not meters) on impassable water, -0.5 on passable.
• todo : make explosion damage get reduced by height offsets if explosion center is not in a trench (In a separate PR)

Changes

Describe adjustments to existing features made in this merge, e.g.

• makes pawn height (bottom edge and top edge) never be lower that 0, which fixes pawns shooting too low if they are both in trench. Previous implementation had a bug, where legs were below 0, so pawns aiming at legs were stuck shooting at ground.
• Makes lower and middle body parts impossible to hit with a bullet, if they are fully below ground

References

Links to the associated issues or other related pull requests, e.g.

• Closes [Bug]: Trenches and Platforms from VFE - Security are broken #3334
• Fixes this bug: https://discord.com/channels/278818534069501953/278818534069501953/1379117196269326366

Reasoning

Why did you choose to implement things this way, e.g.

• Pawns in the same trench are now able to hit each other. This solution is not perfect, as it leaves both pawns with very small hitboxes. Which means that pawns in the same trench have lower hit chances than they should. However, distances are low in this situation, so it still works, better than before.
• Gives raider moving through water a tiny bit of cover. Their ai isn't designed to attack from map edges covered in water, so they just go forth and die without any cover. Water slowing down bullets makes sense and should help AI at least a little. Plus taking cover in a swamp sounds fun.

Use cases for this addition:

• Allows implementing trenches and raised platforms without VE dependency. (But pathing costs still needs to be handled, so rn its better if we only make foxholes, not connected trenches)
• Allows turning 1.6 craters into trenches
• allows submerging pawns into buildings such as turrets

Alternatives

Describe alternative implementations you have considered, e.g.

• ...

Testing

Use this for testing on small craters:

	<Operation Class="PatchOperationAdd">
		<xpath>Defs/ThingDef[defName="CraterSmall"]</xpath>
		<value>
			<fillPercent>0.01</fillPercent> <!-- needed to be considered cover by AI -->
			<passability>Standable</passability>  <!-- craters were pass-only -->
		</value>
	</Operation>

	<Operation Class="PatchOperationAddModExtension">
		<xpath>Defs/ThingDef[defName="CraterSmall"]</xpath>
		<value>
			<li Class="CombatExtended.ModExtensionCover">
				<heightOffset>-0.98</heightOffset>  <!-- eyeballed value-->
			</li>
		</value>
	</Operation>

Check tests you have performed:

• Compiles without warnings
• Game runs without errors
• (For compatibility patches) ...with and without patched mod loaded
• Playtested a colony (specify how long)

[Keshash]

I uploaded this PR as a draft, despite already having another draft, so that code doesn't get lost. My area has severe problems with power blackouts, so it may take a while to finish this.

[github-actions]

You can download the rebuilt assembly for this PR here: https://combatextended.lp-programming.com/CombatExtended-21553034152.zip

[github-actions]

You can download the rebuilt assembly for this PR here: https://combatextended.lp-programming.com/CombatExtended-21553044100.zip

[github-actions]

You can download the rebuilt assembly for this PR here: https://combatextended.lp-programming.com/CombatExtended-21676133745.zip

[N7Huntsman]

It doesn't appear that crouching pawns will raise themselves up to fire from a trench, leading to situations where a pawn crouching in the crater/trench can be shot, but can't fire back.

The shooter outside the trench sees the crouching pawn in the trench at an appropriate height of ~0.18, but the shooter doesn't have a line of sight to the shooter.