Construction Templates

It is possible that a .con.lua construction file can be used by several construction templates that are offered to the player with different properties and icons. They can be defined in metacon.lua files. They contain the same basic metadata as normal constructions:

...
return {
  {
    type = "DYNAMIC",
    availability = { ... },
    description = { ... },
    menuCategory = { ... },
    ...
    createTemplateScript = {
      fileName = "airfield.script@createTemplateFn",
      params = { }
    },
  },
  ...
}

The createTemplateScript reference points to a script that provides the actual content of the template. The function is called when the template shall be used:

...
createTemplateFn(captureParams, params)
  ...
  return result
end
...

The capturedParams contains the parameters forwarded with the script reference in the .con.lua. The params contains the following parameters:

• paramX and paramY are from the keyboard controls. See the basics to find out more about them.
• seed is a number that can be used for randomization purposes. It increases whenever a construction is set or proposed.
• year is the current year.
• templateIndex is the id of the template that was used for this function call.
• All custom parameters of the data.params struct in the current asset construction template.

The function returns a constructions list of the following pattern:

{
  constructions = {
    {
      modules = {  
        [10001000] = "airfield_main_building.module",  
        [10002004] = "airfield_hangar.module",  
        [10070002] = "airfield_passenger_terminal.module"
      },
      constructionFileName = "airfield.con"
      transf = { 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1 },
      params = params
    }
  }
}

Each entry has a list of module slots and assigned modules and a reference to the constructionFileName that shall be used. With the transf property, it is possible to offset the construction relative to the origin of the template. If unset, the same location is used. The params property allows to forward custom parameters to the construction. If unset, the params of the template are forwarded.

For non-modular constructions with templates, the function may simply use an empty list {} for modules.