Loading of files. Versioning of format.

drumsheet/bluemon.csv

@@ -1,5 +1,5 @@
-DRUMSHEET
-tempo,130
+DRUMSHEET,1,2019-10-14
+bpm,130
 factor,4
 len,32
 INSTRUMENTS

drumsheet/drumsheet.lua

@@ -5,6 +5,7 @@ require "midiwire"
 -- now, this can actually play Blue monday!
 -- see https://www.youtube.com/watch?v=Y_hk5P1X7sc&t=164s
 
+VERSION = '2019-10-14'
 LEN = 33
 step = 1
 mout = midiwire.open_out(0)
@@ -37,13 +38,17 @@ pat_save = iup.button{title="save"}
 matrix = iup.matrix{numcol=32, numlin=9, widthdef=10}
 matrix.resizematrix = "YES"
 
+function print_instruments()
+    for i=1,32 do
+    	matrix:setcell(0,i,i)
+    end
+    for i=1,#instruments do
+    	matrix:setcell(i,0,instruments[i][1])
+    end
+end
+
 matrix:setcell(0,0,"DRUMsheet")
-for i=1,32 do
-	matrix:setcell(0,i,i)
-end
-for i=1,#instruments do
-	matrix:setcell(i,0,instruments[i][1])
-end
+print_instruments()
 
 playbtn = iup.button{title="play"}
 stopbtn = iup.button{title="stop"}
@@ -128,17 +133,21 @@ function factor:valuechanged_cb()
 	end
 end
 
+function adjust_len(len)
+    LEN = len + 1
+    for i=1,LEN do
+    	matrix:setcell(0, i, i)
+    end
+    if LEN<33 then
+    	for i=LEN,32 do
+        	matrix:setcell(0, i, "")
+    	end
+    end
+end
+
 function len:valuechanged_cb()
 	if tonumber(len.value) then
-		LEN = tonumber(len.value) + 1
-		for i=1,LEN do
-			matrix:setcell(0, i, i)
-		end
-		if LEN<33 then
-			for i=LEN,32 do
-				matrix:setcell(0, i, "")
-			end
-		end
+		adjust_len(tonumber(len.value))
 		matrix.redraw="YES"
 	end
 end
@@ -213,6 +222,8 @@ end
 
 -- saving & loading
 
+FILEFORMAT_VERSION = 1
+
 function _pat_write(fh, patno)
 	fh:write("PAT,"..patno.."\n")
 	for i=1,#patterns[patno] do
@@ -224,8 +235,8 @@ function pat_save:action()
 	local fname, status = iup.GetFile("./*.csv")
 	if status > -1 then
 		local fh = io.open(fname, "w+")
-		fh:write("DRUMSHEET\n")
-		fh:write("tempo,"..bpm.value.."\n")
+		fh:write("DRUMSHEET," .. FILEFORMAT_VERSION .. "," .. VERSION .. "\n")
+		fh:write("bpm,"..bpm.value.."\n")
 		fh:write("factor,"..factor.value.."\n")
 		fh:write("len,"..len.value.."\n")
 		fh:write("INSTRUMENTS\n")
@@ -241,6 +252,92 @@ function pat_save:action()
 	end
 end
 
+function explode(div,str) -- credit: http://richard.warburton.it
+    if (div=='') then return false end
+    local pos,arr = 0,{}
+    -- for each divider found
+    for st,sp in function() return string.find(str,div,pos,true) end do
+        table.insert(arr,string.sub(str,pos,st-1)) -- Attach chars left of current divider
+        pos = sp + 1 -- Jump past current divider
+    end
+    table.insert(arr,string.sub(str,pos)) -- Attach chars right of last divider
+    return arr
+end
+
+function sheet_read(fname)
+    local data = { instruments={}, patterns = {} }
+    local mode = ""
+    local is_header = {bpm=true, factor=true, len=true}
+    local i = 0
+    local patno = 0
+    for line in io.lines(fname) do
+        local fields = explode(',', line)
+        -- reads header:
+        if mode=="DRUMSHEET" and is_header[fields[1]] then
+            data[fields[1]] = tonumber(fields[2])
+        end
+
+        -- switch to PAT mode in INSTRUMENTS
+        if mode=="INSTRUMENTS" and fields[1]=="PAT" then
+            mode = "PAT"
+        end
+
+        -- reads instruments:
+        if mode=="INSTRUMENTS" and fields[1]~="PAT" then
+            i = i + 1
+            data.instruments[i] = {fields[1], tonumber(fields[2])}
+        end
+
+        -- read patterns:
+        if mode=="PAT" and fields[1]=="PAT" then
+            patno = tonumber(fields[2])
+            data.patterns[patno] = {}
+            i = 0
+        elseif mode=="PAT" then
+            i = i + 1
+            data.patterns[patno][i] = fields
+        end
+
+        if mode=="" and fields[1]=="DRUMSHEET" then
+            -- todo - kontrolovat verzi drumsheetu
+            if not fields[2] or not tonumber(fields[2]) then
+                return nil, "File version not found!"
+            end
+            if tonumber(fields[2])>FILEFORMAT_VERSION then
+                return nil, "File too new!"
+            end
+            mode = "DRUMSHEET"
+
+        end
+        if mode=="DRUMSHEET" and fields[1]=="INSTRUMENTS" then
+            mode = "INSTRUMENTS"
+            i = 0
+        end
+    end
+    return data
+end
+
+function pat_load:action()
+    local fname, status = iup.GetFile("./*.csv")
+    	if status > -1 then
+    	local data, error = sheet_read(fname)
+    	if error then
+    	    iup.Message("File not loaded", error)
+    	else
+    	    bpm.value = data.bpm
+    	    factor.value = data.factor
+    	    len.value = data.len
+    	    adjust_time(data.bpm, data.factor)
+    	    adjust_len(data.len)
+    	    instruments = data.instruments
+    	    print_instruments()
+    	    patterns = data.patterns
+    	    pat_recall(1)
+    	    matrix.redraw = "YES"
+    	end
+    end
+end
+
 
 -- main program
 
@@ -249,4 +346,4 @@ dlg:showxy( iup.CENTER, iup.CENTER )
 
 if (iup.MainLoopLevel()==0) then
   iup.MainLoop()
-end
+end