New MBF21 DEHACKED codepointers (first batch)

[XaserAcheron]

Got the first handful of codepointers done. There's a few more I may try and sneak in (melee attacks and some of skillsaw's suggestions), but some of 'em will need a bit of research to figure out how best to do 'em, and I don't want to hold up the essentials any longer than I must. ;)

Quick summary of the 'pointers:

• Actor pointers:
  • A_SpawnFacing(type, height) -- spawns an actor of type at height z units and sets its angle to the caller's angle.
  • A_MonsterProjectile(type, angle) -- generic monster projectile attack; always sets tracer field.
  • A_MonsterBulletAttack(damage, spread) -- generic monster bullet attack w/horizontal spread; if spread is negative, apply vertical spread equal to 2/3 of this value (approx. equal to SSG vert-spread)
  • A_RadiusDamage(damage, radius) -- generic A_Explode, w/customizable damage and radius (helll yeah)
• Weapon pointers:
  • A_WeaponProjectile(type, angle) -- generic weapon projectile attack; does not consume ammo
  • A_WeaponBulletAttack(damage, spread) -- generic weapon bullet attack; does not consume ammo; same spread behavior as A_MonsterBulletAttack
  • A_WeaponSound(sound, fullvol) -- same as A_PlaySound, but for weapons
  • A_WeaponJump(state, chance) -- same as A_RandomJump, but for weapons
  • A_ConsumeAmmo(amount) -- subtract amount units of ammo. if amount is zero, use the weapon slot's ammopershot. will not reduce ammo below zero.
  • A_CheckAmmo(state, amount) -- jumps to state if ammo is below amount; if amount is zero, use the weapon slot's ammopershot value instead
  • A_RefireTo(state, noammocheck) -- jumps to state if trigger is still held down; will also check ammo unless noammocheck is set
  • A_GunFlashTo(state, nothirdperson) -- sets the weapon's flash state to state; also sets the player's 3rd-person sprite to the player actor's firing frame unless nothirdperson is set

A bit more than the 5 pointers I originally planned, but eh. Low-hanging fruit gets monched. :P

[kraflab]

This isn't hit by any existing code, right? It will only be hit downstream of the new code pointers? Just making sure heretic doesn't need to be considered :^)

[XaserAcheron]

Currently no, but the eventual plan is for P_CheckAmmo to call this function if (mbf21) in my eventual ammopershot PR. Means it still ought not affect Heretic though; presuming you can't set the new complevel there. ;)

[kraflab]

Instead of a method, what do you think about using an array shotammo to match the existing maxammo and clipammo? That will fit in with the use of maxammo and clipammo in d_deh, assuming we will be making it all configurable the same way.

[XaserAcheron]

That makes sense -- though that seems like a thing to do for the new ammopershot PR. I'll probably rip out the P_GetAmmoPerShot function completely if it's indeed as simple as indexing an array. ;)

[kraflab]

We need to declare this variable at the top and then set it here to avoid a warning in C, right? 🤓

[XaserAcheron]

Heh, maybe. :P -- Fixed for consistency at least. ;)

[kraflab]

Please add a code pointers header in https://github.com/kraflab/dsda-doom/blob/master/prboom2/src/mbf21.md and link this pr as well as list the ones added here. Just basic info is fine - it isn't meant to be a spec for public consumption so we can go into more detail once mbf21 is more finalized.

[XaserAcheron]

Just pushed an update to mbf21.md -- in this PR; it's self-referential now. :P