A REAPER script for automatically editing backgrounds

Loop Item to Fill Scene.lua

--[[ 
	I, Jamie Hardt, the author, hereby release this work to the public domain.

	This script reads regions created by the "Import Video Cuts from EDL.lua" script and
	attempts to intelligently loop regions to fill them.
]]

function eachMarker(proj) 
	local i = 0
	local retval, markerCount, regionCount = reaper.CountProjectMarkers(proj)
	return function () 
		i = i + 1
		if i < markerCount + regionCount then
			local rval, isregion, startTime, endTime, name, regionIndexNum = reaper.EnumProjectMarkers(i,proj)
			return  { isRegion = isregion, startTime = startTime, endTime = endTime, name = name, num = regionIndexNum, globalIndex = i }
		end
	end

end

function eachRegion(proj)
	local markerIter = eachMarker(proj)

	return function () 
		while true do
			local m = markerIter()
			if m then
				if m.isRegion then return m end
			else
				break
			end
		end
	end
end
function sceneRegionsByTime(proj)
	local sceneRegions = {}

	for region in eachRegion(0) do
		if region.name and sceneForRegionName(region.name) and region.num > 1000 then
			table.insert(sceneRegions,region)
		end
	end

	local timeSort = function (a,b)
		return a.startTime < b.startTime
	end
	
	table.sort(sceneRegions, timeSort)
	return sceneRegions
end

function sceneForRegionName(regionName)
	return regionName:match("V?(%a*%d+)")
end


function eachScene(proj)
	local sceneRegions = sceneRegionsByTime(proj)
	
	if #sceneRegions == 0 then
		return nil
	end

	local i = 1

	local lastStart = sceneRegions[1].startTime	
	local lastEnd   = sceneRegions[1].endTime	
	local lastSceneName = sceneForRegionName(sceneRegions[1].name)

	return function ()
		local retScene, retStart, retEnd = nil, nil, nil
		while i < #sceneRegions do
			i = i + 1
			local thisRegion = sceneRegions[i]

			if thisRegion then 
				local thisSceneName = sceneForRegionName(thisRegion.name)	
				
				if thisSceneName ~= lastSceneName then
					retScene, retStart, retEnd = lastSceneName, lastStart, lastEnd
					lastStart = thisRegion.startTime
					lastEnd = thisRegion.endTime
					lastSceneName = thisSceneName
					break 
				else
					lastEnd = thisRegion.endTime
				end
			else
				return retScene, retStart, retEnd
			end
		end
			
		
		return retScene, retStart, retEnd 
	end
end

function selectedMediaItems(proj)
	local retval = {}

	for i = 0, reaper.CountSelectedMediaItems(proj) do
		local thisItem = reaper.GetSelectedMediaItem(proj,i)
		table.insert(retval, thisItem)
	end
	return retval
end

function sceneForRegionName(regionName)
	return regionName:match("V?(%a*%d+)")
end

function getRegionAtTime(project, time)
	local lastMarker , lastRegion = reaper.GetLastMarkerAndCurRegion(project, time)
	local rval, isRegion, startTime, endTime, name, regionIndex = reaper.EnumProjectMarkers(lastRegion)
	return startTime, endTime, name, regionIndex
end

function getRegionAtCursorPosition()
	return getRegionAtTime(0, reaper.GetCursorPosition() )
end

function getSceneAtCursorPosition() 
	local startTime, endTime, name, regionIndex = getRegionAtCursorPosition()	
	return sceneForRegionName(name)
end


sceneToFill = getSceneAtCursorPosition()

itemsToUse = selectedMediaItems(0)

if #itemsToUse == 0 then
	reaper.ShowMessageBox("You must selected media items to fill the scene.","Select Media Items",0)
	return
end

if #sceneToFill == nil then
	reaper.ShowMessageBox("The selected area does not have a scene defined in the region list.",0)
	return
end

for scene, startTime, endTime in eachScene(0) do
	if scene == sceneToFill	then
		-- reaper.ShowConsoleMsg("Will set")
		for k, item in pairs(itemsToUse) do
			reaper.SetMediaItemPosition(item,startTime, false)
			reaper.SetMediaItemLength(item,endTime - startTime,false)
		end
	end

	reaper.UpdateArrange()
end