evn.ClipTransformPoints.lua

script_name="Clip Transform Points"
script_description="first and last lines selected should have clips with the same number of points. transforms each point's position from first to last line over the selected lines (WARNING: wipes out any clip on intermediate lines"
script_author="iamevn"
script_version="0.1"
script_namespace="evn.ClipTransformPoints"


function transform(subs, sel)

  --[[
    so here's the plan:
    A - acceleration (default 1)
    N - number of lines selected
  ]]--
  A = 1.0
  S = 1
  N = #sel

  inverseClip = string.match(subs[sel[S]].text, "\\iclip%(.-%)") ~= nil

  initialClip = string.match(subs[sel[S]].text, "\\i?clip%((.-)%)")
  initialTable = {}
  for s in string.gmatch(initialClip, "%S+") do
    table.insert(initialTable, s)
  end

  finalClip = string.match(subs[sel[N]].text, "\\i?clip%((.-)%)")
  finalTable = {}
  for s in string.gmatch(finalClip, "%S+") do
    table.insert(finalTable, s)
  end
  for index, line_idx in ipairs(sel) do
    progress = (index - S) / (N - S)
    progress = math.pow(progress, A)

    lineTable = {}
    for key, s in ipairs(initialTable) do
      if tonumber(s) == nil then
	table.insert(lineTable, s)
      else
	IVAL = initialTable[key]
	FVAL = finalTable[key]
	value = (1 - progress) * IVAL + progress * FVAL
	table.insert(lineTable, value)
      end
    end

    body = ""
    for i, s in ipairs(lineTable) do
      if #body == 0 then
	body = body .. s
      else
	body = body .. " " .. s
      end
    end

    line = subs[line_idx]
    line.text = string.gsub(line.text, "\\i?clip%(.-%)", "")
    if inverseClip then
      line.text = string.gsub(line.text, "}", "\\iclip(" .. body .. ")}")
    else
      line.text = string.gsub(line.text, "}", "\\clip(" .. body .. ")}")
    end
    subs[line_idx] = line
  end
end



--[[
  validates that the first and last lines have "matching" clips
  (matching in the sense that they have the same number of points
    and the same sorts of lines in the same places)
]]--
function validate(subs, sel)
  if #sel < 3 then
    return false
  end

  initialClip = string.match(subs[sel[1]].text, "\\i?clip%((.-)%)")
  finalClip = string.match(subs[sel[#sel]].text, "\\i?clip%((.-)%)")

  if initialClip == nil or finalClip == nil then
    return false
  end

  initialTable = {}
  for s in string.gmatch(initialClip, "%S+") do
    table.insert(initialTable, s)
  end

  finalTable = {}
  for s in string.gmatch(finalClip, "%S+") do
    table.insert(finalTable, s)
  end

  if #initialTable ~= #finalTable then
    return false
  end

  for i = 1, #initialTable do
    a = initialTable[i]
    b = finalTable[i]

    if tonumber(a) == nil and tonumber(b) == nil then
      if a ~= b then
	return false
      end
    elseif tonumber(a) ~= nil and tonumber(b) ~= nil then
      --everything's good
    else
      return false
    end
  end
  return true
end

aegisub.register_macro(script_name, script_description, transform, validate)

• select a bunch of lines (first and last need to have clips that have the same number of control points of the same types)
• run script
• lines now have clip interpolated across them

(I should probably have it split the line(s) into frame by frame things but you can do that with other scripts just fine already.)