Terrain library for Lua (`terrain_t`, `t_splash_t`, `t_footstep_t`, `t_overlay_t`)

Summary

This branch exposes terrain_t, t_splash_t, t_footstep_t, t_overlay_t, their respective global iteratable tables, and terrain-related functions, as well as exposing terrain from mobj_t, and stairjank and outrun from player_t to Lua.

The game comes with no default overlays, so that aspect is largely untested - I have no reason to think it would not work, though.

It changes the following:

• Exposes the following variables:
  • terrain_t object:
    • get: valid, name, hash, splashid, footstepid, overlayid, friction, offroad, damagetype, trickpanel, speedpad, speedpadangle, springstrength, springstarcolor, outrun, floorclip, flags
  • t_splash_t object:
    • get: valid, name, hash, mobjtype, sfx, scale, color, pushh, pushv, spread, cone, numparticles
  • t_footstep_t object:
    • get: valid, name, hash, mobjtype, sfx, scale, color, pushh, pushv, spread, cone, sfxfreq, frequency, requiredspeed
  • t_overlay_t object:
    • get: valid, name, hash, states, scale, color, speed
  • mobj_t object:
    • get and set: terrain
  • player_t object:
    • get and set: stairjank, outrun
• Exposes the following globals:
  • terrains (table with all available terrains, can be accessed through index or name such as terrains[0] or terrains["Default"]), #terrains (counts how many terrains there are), terrains.iterate (iteratable for all terrains).
  • footsteps, #footsteps, terrains.iterate (likewise, but with footsteps).
  • splashes, #splashes, splashes.iterate (likewise, but with splashes).
  • overlays, #overlays, overlays.iterate (likewise, but with overlays).
• Exposes the following constants:
  • t_overlay_action_t: TOV_UNDEFINED, TOV_STILL, TOV_MOVING, TOV__MAX
  • terrain_flags_t: TRF_LIQUID, TRF_SNEAKERPANEL, TRF_STAIRJANK, TRF_TRIPWIRE, TRF_REMAP
• Exposes the following functions:
  • terrain_t K_GetDefaultTerrain()
  • terrain_t K_GetTerrainForTextureName(string name)
  • terrain_t K_GetTerrainForTextureNum(integer id)
  • void K_ProcessTerrainEffect(mobj_t mo)
  • void K_SetDefaultFriction(mobj_t mo)
  • void K_SpawnSplashForMobj(mobj_t mo, [fixed_t impact])
  • void K_HandleFootstepParticles(mobj_t mo)
  • void K_UpdateTerrainOverlay(mobj_t mo)
  • boolean K_TerrainHasAffect(terrain_t terrain, [boolean badonly]) (Note: this will report every terrain as having an affect except for NoRemap, likely because of the friction condition being > 0 rather than != ORIG_FRICTION. I didn't fix this, but let me know if this warrants a commit to do so.)

Testing

Testing environment: ringracers_terrainLib.exe -console -skipintro -warp RR_TESTRUN +addfile terraintest.lua

I used a script, terraintest.lua, to test the following additions:

• It will print all exposed constants in the console.
• Has a HUD hook that will display all of the terrain values that the player is standing on. Can be disabled using terrainhuddebug 0.
• testiterateterrain/testforloopterrain, testiteratefootstep/testforloopfootstep, testiteratesplash/testforloopsplash and testiterateoverlay/testforloopoverlay tests for..do loops and the iterate functions directed at the terrains, footsteps, splashes and overlays globals respectively, by printing all of their values, as well as their affectness. Note that there are no overlays by default in the base game, so it will print nothing for those cases.
• testterrain allows the player to set any given terrain to their mobj, running K_ProcessTerrainEffect, K_SetDefaultFriction, K_HandleFootstepParticles in the process.
• findterrain, findsplash, findfootstep and findoverlay take a number or string, and it will print the values of the object that corresponds with that ID or string.
• defaultterrain prints the info of the default terrain, running K_GetDefaultTerrain in the process.
• splashme runs K_SpawnSplashForMobj on the player mobj, with an optional parameter that allows to set the strength of the splash.
• findterrainonfloor runs K_GetTerrainForTextureName to get the terrain of the floor and ceiling, printing their values.
• findterrainonwalls runs K_GetTerrainForTextureNum to get the terrain of all walls inside the sector, printing their values.

Changelog

• Adding the following global tables to Lua: terrains, splashes, footsteps, overlays
• Exposed terrain_t, t_splash_t, t_footstep_t, t_overlay_t types to Lua (get only).
• Exposed player_t members stairjank and outrun to Lua (get and set).
• Exposed mobj_t member terrain to Lua (get and set).
• Exposed t_overlay_action_t constants: TOV_UNDEFINED, TOV_STILL, TOV_MOVING, TOV__MAX
• Exposed terrain_flags_t constants: TRF_LIQUID, TRF_SNEAKERPANEL, TRF_STAIRJANK, TRF_TRIPWIRE, TRF_REMAP
• Exposed the following terrain-related functions to Lua: K_GetDefaultTerrain, K_GetTerrainForTextureName, K_GetTerrainForTextureNum, K_ProcessTerrainEffect, K_SetDefaultFriction, K_SpawnSplashForMobj, K_HandleFootstepParticles, K_UpdateTerrainOverlay, K_TerrainHasAffect.