ReaScript: get fx parameter index from envelope?

[Alkamist]

Hello!

Is there an easy way to get the fx parameter index from an envelope in ReaScript? Right now I have to loop through all of my fx and parameters to compare names and check the indexes. It would be nice if there was an easy way. Thanks for any help!

[Lokasenna]

If you already know which effect the envelope is attached to, you can get the parameter index from the envelope state chunk.

local track = reaper.GetTrack(0, 0)
local env = reaper.GetTrackEnvelope(track, 0)
local _, chunk = reaper.GetEnvelopeStateChunk(env, "", false)

reaper.ShowConsoleMsg(chunk)

--[[ 

spits out:

<PARMENV 4 0.000000 1.000000 0.500000
  ACT 1 -1
  VIS 1 1 1
  LANEHEIGHT 0 0
  ARM 0
  DEFSHAPE 0 -1 -1
  PT 0 0.5 0
  PT 1 0.5 0
  PT 2 0.3 0 0 1
>
]]--

The parameter index is the very first number there, so it's an easy string match:

local paramIndex = chunk:match("PARMENV (%d+)")

(Don't forget to convert it to a number afterward)

[Alkamist]

Originally Posted by Lokasenna

If you already know which effect the envelope is attached to, you can get the parameter index from the envelope state chunk.

Thank you so much, that works perfectly! Any tips on how to get the index of the FX that the envelope is attached to?

[Edgemeal]

Not sure if this is any better, but gets fx index and the fx param index..

function Index_From_Env(env)
  local track = reaper.Envelope_GetParentTrack(env)
  local fx_count = reaper.TrackFX_GetCount(track)
  for j = 0, fx_count-1 do
    local fxparam_count = reaper.TrackFX_GetNumParams(track, j)
    for k = 0, fxparam_count-1 do
      if reaper.GetFXEnvelope(track, j, k, false) == env then
        return j,k -- returns fx_index and fx_param_index.
      end
    end
  end
end

[Alkamist]

Originally Posted by Edgemeal

Not sure if this is any better, but gets fx index and the fx param index..

function Index_From_Env(env)
  local track = reaper.Envelope_GetParentTrack(env)
  local fx_count = reaper.TrackFX_GetCount(track)
  for j = 0, fx_count-1 do
    local fxparam_count = reaper.TrackFX_GetNumParams(track, j)
    for k = 0, fxparam_count-1 do
      if reaper.GetFXEnvelope(track, j, k, false) == env then
        return j,k -- returns fx_index and fx_param_index.
      end
    end
  end
end

That works really well. Thank you very much!