zaibuyidao_Delete Regions of Selected Items.lua

-- @description Delete Regions of Selected Items
-- @version 1.0
-- @author zaibuyidao
-- @changelog
--   New Script
-- @links
--   https://www.soundengine.cn/user/%E5%86%8D%E8%A3%9C%E4%B8%80%E5%88%80
--   https://github.com/zaibuyidao/ReaScripts
-- @donate http://www.paypal.me/zaibuyidao
-- @about Requires JS_ReaScriptAPI & SWS Extension

local bias = 0.003 -- 补偿偏差值
local absolute = false

function Msg(param) 
  reaper.ShowConsoleMsg(tostring(param) .. "\n") 
end

function get_all_regions()
  local result = {}
  local _, num_markers, num_regions = reaper.CountProjectMarkers(0)
  for i = 0, num_markers + num_regions - 1 do
    local retval, isrgn, pos, rgnend, name, markrgnindexnumber, color = reaper.EnumProjectMarkers3(0, i)
    if retval ~= nil and isrgn then
      table.insert(result, {
        index = markrgnindexnumber,
        isrgn = isrgn,
        left = pos,
        right = rgnend,
        name = name,
        color = color
      })
    end
  end
  return result
end

function get_sel_regions()
  local all_regions = get_all_regions()
  if #all_regions == 0 then return {} end
  local sel_index = {}
  local item_count = reaper.CountSelectedMediaItems(0)
  if item_count == 0 then return {} end

  -- 获取item列表
  local items = {}
  for i = 1, item_count do
    local item = reaper.GetSelectedMediaItem(0, i-1)
    if item ~= nil then
      local item_pos = reaper.GetMediaItemInfo_Value(item, "D_POSITION")
      local item_len = reaper.GetMediaItemInfo_Value(item, "D_LENGTH")
      local item_end = item_pos + item_len
      table.insert(items, {left=item_pos,right=item_end} )
    end
  end

  -- 合并item
  local merged_items = {}
  table.sort(items, function(a,b)
    return a.left < b.left
  end)
  local cur = {
    left = items[1].left,
    right = items[1].right
  }
  for i,item in ipairs(items) do
    if cur.right - item.left > 0 then -- 确定区域是否为相交
      cur.right = math.max(item.right,cur.right)
    else
      table.insert(merged_items, cur)
      cur = {
        left = item.left,
        right = item.right
      }
    end
  end
  table.insert(merged_items, cur)

  -- 标记选中区间
  for _, merged_item in ipairs(merged_items) do
    local l, r = 1, #all_regions
    -- 查找第一个左端点在item左侧的区间
    while l <= r do
      local mid = math.floor((l+r)/2)
      if (all_regions[mid].left - bias) > merged_item.left then
        r = mid - 1
      else 
        l = mid + 1
      end
    end

    if absolute then
      if math.abs( (merged_item.right - merged_item.left) - (all_regions[r].right - all_regions[r].left) ) <= bias * 2 then
        sel_index[r] = true
      end
    else
      if r ~= 0 then
        if merged_item.right <= all_regions[r].right then -- if merged_item.right <= all_regions[r].right + bias then
          sel_index[r] = true
        end
      end
    end
  end

  -- 处理结果
  local result = {}
  local indexs = {}
  for k, _ in pairs(sel_index) do table.insert(indexs, k) end
  table.sort(indexs)
  for _, v in ipairs(indexs) do table.insert(result, all_regions[v]) end

  return result
end

local sel_regions = get_sel_regions()

function del_region(region)
  reaper.DeleteProjectMarker( 0, region.index, region.isrgn )
end

for i,region in ipairs(sel_regions) do
  del_region(region)
end

reaper.Undo_EndBlock('Delete Regions of Selected Items', -1)
reaper.PreventUIRefresh(-1)
reaper.UpdateArrange()