Battle Stance Gadget

function gadget:GetInfo()
  return {
    name      = "battlestance",
    desc      = "Toggle between Defensive, Assault and Sprint",
    author    = "Zealot",
    date      = "13th July 2013",
    license   = "GNU LGPL, v2.1 or later",
    layer     = 101,  -------------------------What does this do?
    enabled   = true  --  loaded by default?
  }
end


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if (not gadgetHandler:IsSyncedCode()) then
  return
end


local EditUnitCmdDesc = Spring.EditUnitCmdDesc
local FindUnitCmdDesc = Spring.FindUnitCmdDesc
local InsertUnitCmdDesc = Spring.InsertUnitCmdDesc
local GiveOrderToUnit = Spring.GiveOrderToUnit
local SetUnitNeutral = Spring.SetUnitNeutral
local GetUnitMoveTypeData = Spring.GetUnitMoveTypeData
local SetGroundMoveTypeData = Spring.MoveCtrl.SetGroundMoveTypeData
local SetUnitCloak = Spring.SetUnitCloak
local SetUnitArmored = Spring.SetUnitArmored
local GetUnitCmdDescs = Spring.GetUnitCmdDescs


-- constants

local ARMOUR_DEF = 0.2
local ARMOUR_ASS = 1.3




-----setup command


-----The List of units who can change their stance. (units that get this gadget)


local STANCE = {
    [UnitDefNames["armcv"].id] = true,
    [UnitDefNames["corak"].id] = true,
    [UnitDefNames["armpw"].id] = true,
    [UnitDefNames["armwar"].id] = true,
    [UnitDefNames["armrock"].id] = true,
    [UnitDefNames["corstorm"].id] = true,
    [UnitDefNames["corthud"].id] = true,
    [UnitDefNames["armzeus"].id] = true,
    [UnitDefNames["cornecro"].id] = true,
    [UnitDefNames["corpyro"].id] = true,
    [UnitDefNames["armsnipe"].id] = true,
    [UnitDefNames["cormort"].id] = true,

}

local stanceList = {}

local CMD_STANCE = 34583


            ----  Create the button

local stanceCmdDesc = {
    id      = CMD_STANCE,
    name    = "togglestance",
    action  = "togglestance",
    type    = CMDTYPE.ICON_MODE,
    tooltip = 'Toggle between Defensive, Assault and Sprint.',
    params  = {1, "Defensive", "Assault", "Sprint"}
}


            ---- Insert the button on the units who get it


function gadget:UnitCreated(unitID, unitDefID, teamID, builderID)
    if STANCE[unitDefID] then
        InsertUnitCmdDesc(unitID, 502, stanceCmdDesc)
        local ms = UnitDefs[unitDefID].speed
        stanceList[unitID] = {orgspeed=ms}

  end
end


            ---- Remove the button when a unit dies (as it is no longer needed)

function gadget:UnitDestroyed(unitID, unitDefID, unitTeam)
  stanceList[unitID] = nil
end



-----------enable the command




function gadget:AllowCommand(unitID, unitDefID, teamID, cmdID, cmdParams, cmdOptions)
if STANCE[unitDefID] then
    if cmdID == CMD_STANCE then
            local cmdDescID = FindUnitCmdDesc(unitID, CMD_STANCE)
            --Spring.Echo("cmdparams[1]=" .. tostring(cmdParams[1]))
            if not cmdDescID then return false end


             if  cmdParams[1] == 1 then  --Assault stance

                    --units decloak range to 250
                    SetUnitCloak(unitID, true, 250)

                     --unit receives normal damage as in unitdef
                    SetUnitArmored(unitID, false)

                    --unit moves at normal speed as in unitdef
                    SetGroundMoveTypeData(unitID, {
                    maxSpeed=stanceList[unitID].orgspeed * 1})



            elseif
                     cmdParams[1] == 2 then    --Sprint stance

                    --set units decloak range to 750
                    SetUnitCloak(unitID, true, 750)

                    --multiply damage received by ARMOUR_ASS amount (defined above)
                    SetUnitArmored(unitID, true, ARMOUR_ASS)
                    --unit moves at 1.6x unitdef speed
                    SetGroundMoveTypeData(unitID, {maxSpeed=stanceList[unitID].orgspeed * 1.6 })



            elseif
                     cmdParams[1] == 0 then   -- Defensive stance


                    --set units decloak range to 125
                    SetUnitCloak(unitID, true, 125)

                    --multiply damage received by ARMOUR_DEF amount (defined above)
                    SetUnitArmored(unitID, true, ARMOUR_DEF)

                    --unit moves at 1/3 unitdef speed
                    SetGroundMoveTypeData(unitID, {maxSpeed=stanceList[unitID].orgspeed / 3 })

            end

      --you can't edit a single value in the params table for
        --editUnitCmdDesc, so we generate a new table

        local updatedCmdParams = {
            cmdParams[1],
            stanceCmdDesc.params[2],
            stanceCmdDesc.params[3],
            stanceCmdDesc.params[4]
        }
        Spring.EditUnitCmdDesc(unitID, cmdDescID, { params = updatedCmdParams})
        return false
        end
        return true
    end
  end