Location

resources.lua is a file in the Gamedata/ directory of a Spring Game.
resources_map.lua is a file in the Gamedata/ directory of a Spring Map.

Purpose

This file is used by a game to reference textures for use in Custom Explosion Generators, as well as various default explosions and other engine textures such as default trees and water etc. Maps have a corresponding file, resources_map.lua which behaves in the same way.

Source

The engine source code which parses the data from this file is viewable here:

• rts/Rendering/ProjectileDrawer.cpp (smoke, groundfx & projectiletextures) resources_map.lua is only read here.

• rts/Rendering/GroundDecalHandler.cpp (scars)
• rts/Rendering/Env/AdvTreeGenerator.cpp (trees)
• rts/Map/MapInfo.cpp (caustics & maps)

Details

The engine loads textures from seven subtables within the graphics subtable of the returned resources table. Certain tables are automatically added by the engine if a game is not overriding them, they are numerical arrays whereas all others are key-value associative arrays. Engine defaults which are required to be present are included in the #Automatic example below.

• caustics - Textures used with bumpmapped water. Automatically added by the engine.
  
• smoke - Textures used for engine default smoke. Automatically added by the engine.
  
• scars - Textures used for the burn scars left on the map by weapon explosions. Automatically added by the engine.
  
• trees - Textures for engine default trees.
  
• maps - Base textures in case a map does not provide it's own.
  
• groundfx - Game or Map specific textures for CSimpleGroundFlash CEG's as well as engine default explosion groundflash.
  
• projectiletextures - Game or Map specific textures for the other CEG-Classes as well as engine defaults. This is the only table that is read from resources_map.lua
  

Example

Automatic

The following example (which is becoming a de facto standard) sets out the engine default textures, and recursively adds any textures from the game's Bitmaps/projectileTextures/ and Bitmaps/groundFX/ directories, respectively. It will ignore any directories created by SVN, and can be easily edited to filter out git or any other version control software.

local  resources = {
    graphics = {
      -- Spring Defaults
      trees = {
        bark           = 'Bark.bmp',
        leaf           = 'bleaf.bmp',
        gran1          = 'gran.bmp',
        gran2          = 'gran2.bmp',
        birch1         = 'birch1.bmp',
        birch2         = 'birch2.bmp',
        birch3         = 'birch3.bmp',
      },
      maps = {
        detailtex      = 'detailtex2.bmp',
        watertex       = 'ocean.jpg',
      },
      groundfx = {
        groundflash    = 'groundflash.tga',
        groundring     = 'groundring.tga',
        seismic        = 'circles.tga',
      },
      projectiletextures = {
        circularthingy = 'circularthingy.tga',
        laserend       = 'laserend.tga',
        laserfalloff   = 'laserfalloff.tga',
        randdots       = 'randdots.tga', 
        smoketrail     = 'smoketrail.tga',
        wake           = 'wake.tga',
        flare          = 'flare.tga',
        explo          = 'explo.tga',
        explofade      = 'explofade.tga',
        heatcloud      = 'explo.tga',
        flame          = 'flame.tga',
        muzzleside     = 'muzzleside.tga',
        muzzlefront    = 'muzzlefront.tga',
        largebeam      = 'largelaserfalloff.tga',
      },
    }
  }

local VFSUtils = VFS.Include('gamedata/VFSUtils.lua')

local function AutoAdd(subDir, map, filter)
  local dirList = RecursiveFileSearch("bitmaps/" .. subDir)
  for _, fullPath in ipairs(dirList) do
    local path, key, ext = fullPath:match("bitmaps/(.*/(.*)%.(.*))")
    if not fullPath:match("/%.svn") then
    local subTable = resources["graphics"][subDir] or {}
    resources["graphics"][subDir] = subTable
      if not filter or filter == ext then
        if not map then
          table.insert(subTable, path)
        else -- a mapped subtable
          subTable[key] = path
        end
      end
    end
  end
end

-- Add mod projectiletextures and groundfx
AutoAdd("projectiletextures", true)
AutoAdd("groundfx", true)

return resources

External

cont/base/springcontent/gamedata/resources.lua - Engine base content resources.lua