From 9b6bbf508b0e95b354115ed9077a639bedb45ae2 Mon Sep 17 00:00:00 2001
From: XeonSquared <redtailedairways@gmail.com>
Date: Sun, 4 Jun 2023 16:07:42 +1000
Subject: [PATCH] add multi-terminal patch

---
 multiterm/lib/vtansi.lua    | 268 ++++++++++++++++++++++++++++++++++++
 multiterm/package.cfg       |   4 +
 multiterm/service/getty.lua |  88 ++++++++++++
 3 files changed, 360 insertions(+)
 create mode 100644 multiterm/lib/vtansi.lua
 create mode 100644 multiterm/package.cfg
 create mode 100644 multiterm/service/getty.lua

diff --git a/multiterm/lib/vtansi.lua b/multiterm/lib/vtansi.lua
new file mode 100644
index 0000000..c7c4863
--- /dev/null
+++ b/multiterm/lib/vtansi.lua
@@ -0,0 +1,268 @@
+local vtansi = {}
+local keyboardIgnore = {}
+vtansi.activeBuffers = {}
+vtansi.sequences = {
+ [28] = "\n", -- newline
+ [200] = "\27[A", -- up
+ [203] = "\27[D", -- left
+ [205] = "\27[C", -- right
+ [208] = "\27[B", -- down
+ [201] = "\27[5~", -- page up
+ [209] = "\27[6~" -- page down
+}
+vtansi.keys = {}
+vtansi.keys[0x38] = "lalt"
+vtansi.keys[0xB8] = "ralt"
+function vtansi.saveToBuffer(gpu,idx)
+ gpu.bitblt(idx, nil, nil, nil, nil, 0)
+end
+function vtansi.loadFromBuffer(gpu,idx)
+ gpu.bitblt(0, nil, nil, nil, nil, idx)
+end
+function vtansi.switchToBuffer(gpu,idx)
+ -- copy screen to the active buffer
+ vtansi.saveToBuffer(gpu,vtansi.activeBuffers[gpu.address])
+ -- copy the new buffer to the screen
+ vtansi.loadFromBuffer(gpu,idx)
+ vtansi.activeBuffers[gpu.address] = idx
+end
+function vtansi.vtemu(gpu,bn) -- table number -- function -- takes GPU component proxy *gpu* and returns a function to write to it in a manner like an ANSI terminal, either allocating a new buffer or using *bn*.
+ local colours = {0x0,0xFF0000,0x00FF00,0xFFFF00,0x0000FF,0xFF00FF,0x00B6FF,0xFFFFFF}
+ local mx, my = gpu.maxResolution()
+ local cx, cy = 1, 1
+ local pc = " "
+ local lc = ""
+ local mode = 0 -- 0 normal, 1 escape, 2 command
+ local lw = true
+ local sx, sy = 1,1
+ local cs = ""
+ local bg, fg = 0, 0xFFFFFF
+
+ local buffer = bn or gpu.allocateBuffer(mx,my)
+ if not vtansi.activeBuffers[gpu.address] then
+  vtansi.activeBuffers[gpu.address] = buffer
+ end
+ local oldActiveBuffer = vtansi.activeBuffers[gpu.address]
+ gpu.setActiveBuffer(buffer)
+ -- setup
+ gpu.setResolution(mx,my)
+ gpu.fill(1,1,mx,my," ")
+ local function checkCursor()
+  if cx > mx and lw then
+   cx, cy = 1, cy+1
+  end
+  if cy > my then
+   gpu.copy(1,2,mx,my-1,0,-1)
+   gpu.fill(1,my,mx,1," ")
+   cy=my
+  end
+  if cy < 1 then cy = 1 end
+  if cx < 1 then cx = 1 end
+ end
+ gpu.setActiveBuffer(oldActiveBuffer)
+
+ local function termwrite(s)
+  if vtansi.activeBuffers[gpu.address] == buffer then
+   gpu.setActiveBuffer(0)
+  else
+   gpu.setActiveBuffer(buffer)
+  end
+  local wb = ""
+  local lb, ec = nil, nil
+  local function flushwb()
+   while wb:len() > 0 do
+    checkCursor()
+    local wl = wb:sub(1,mx-cx+1)
+    wb = wb:sub(wl:len()+1)
+    gpu.set(cx, cy, wl)
+    cx = cx + wl:len()
+   end
+  end
+  local rs = ""
+  s=s:gsub("\8","\27[D")
+  pc = gpu.get(cx,cy)
+  gpu.setForeground(fg)
+  gpu.setBackground(bg)
+  gpu.set(cx,cy,pc)
+  for cc in s:gmatch(".") do
+   if mode == 0 then
+    if cc == "\n" then
+     flushwb()
+     cx,cy = 1, cy+1
+     checkCursor()
+    elseif cc == "\t" then
+     wb=wb..(" "):rep(8*((cx+9)//8))
+    elseif cc == "\27" then
+     flushwb()
+     mode = 1
+    else
+     wb = wb .. cc
+    end
+   elseif mode == 1 then
+    if cc == "[" then
+     mode = 2
+    else
+     mode = 0
+    end
+   elseif mode == 2 then
+    if cc:match("[%d;]") then
+     cs = cs .. cc
+    else
+     mode = 0
+     local tA = {}
+     for s in cs:gmatch("%d+") do
+      tA[#tA+1] = tonumber(s)
+     end
+     if cc == "H" then
+      cx, cy = math.min(mx,tA[1] or 1), math.min(my,tA[2] or 1)
+     elseif cc == "A" then
+      for i = 1, (tA[1] or 1) do
+       cy = cy - 1
+       checkCursor()
+      end
+     elseif cc == "B" then
+      for i = 1, (tA[1] or 1) do
+       cy = cy + 1
+       checkCursor()
+      end
+     elseif cc == "C" then
+      for i = 1, (tA[1] or 1) do
+       cx = cx + 1
+       checkCursor()
+      end
+     elseif cc == "D" then
+      for i = 1, (tA[1] or 1) do
+       cx = cx - 1
+       checkCursor()
+      end
+     elseif cc == "s" then
+      sx, sy = cx, cy
+     elseif cc == "u" then
+      cx, cy = sx, sy
+     elseif cc == "n" and tA[1] == 6 then
+      rs = string.format("%s\27[%d;%dR",rs,cx,cy)
+      dprint(string.format("reporting %d;%d as current cursor position",cx,cy))
+     elseif cc == "K" and tA[1] == 1 then
+      gpu.fill(1,cy,cx,1," ")
+     elseif cc == "K" and tA[1] == 2 then
+      gpu.fill(cx,cy,mx,1," ")
+     elseif cc == "K" then
+      gpu.fill(1,cy,mx,1," ")
+     elseif cc == "J" and tA[1] == 1 then
+      gpu.fill(1,1,mx,cy," ")
+     elseif cc == "J" and tA[1] == 2 then
+      gpu.fill(1,1,mx,my," ")
+      cx, cy = 1, 1
+     elseif cc == "J" then
+      gpu.fill(1,cy,mx,my," ")
+     elseif cc == "m" then
+      for _,num in ipairs(tA) do
+       if num == 0 then
+        fg,bg,ec,lb = 0xFFFFFF,0,false,true
+       elseif num == 7 then
+        local nfg,nbg = bg, fg
+        fg, bg = nfg, nbg
+       elseif num > 29 and num < 38 then
+        fg = colours[num-29]
+       elseif num > 39 and num < 48 then
+        bg = colours[num-39]
+       elseif num == 100 or num == 8 then -- disable local echo
+        ec = false
+       elseif num == 101 then -- disable line mode
+        lb = false
+       end
+      end
+      gpu.setForeground(fg)
+      gpu.setBackground(bg)
+     end
+     cs = ""
+     checkCursor()
+    end
+   end
+  end
+  flushwb()
+  checkCursor()
+  pc = gpu.get(cx,cy)
+  gpu.setForeground(bg)
+  gpu.setBackground(fg)
+  gpu.set(cx,cy,pc)
+  gpu.setForeground(fg)
+  gpu.setBackground(bg)
+  return rs, lb, ec
+ end
+
+ return termwrite, buffer
+end
+
+function vtansi.vtsession(gpua,scra,bn) -- string string number -- function function function -- creates a process to handle the GPU and screen address combination *gpua*/*scra*, optionally using buffer number *bn* specifically. Returns read, write and "close" functions.
+ local modifiers = {}
+ local gpu = component.proxy(gpua)
+-- gpu.bind(scra)
+ local write, bn = vtansi.vtemu(gpu,bn)
+ local kba = {}
+ for k,v in ipairs(component.invoke(scra,"getKeyboards")) do
+  kba[v]=true
+ end
+ local buf, lbuf, echo = "", false, false
+ os.spawn(function()
+  while true do
+   local ty,ka,ch,kc = coroutine.yield()
+   if keyboardIgnore[ka] == bn then
+    keyboardIgnore[ka] = nil
+   end
+   if kba[ka] and vtansi.keys[kc] then
+    modifiers[vtansi.keys[kc]] = ty == "key_down"
+   end
+   if ty == "key_down" and kba[ka] and vtansi.activeBuffers[gpua] == bn then
+    if false then
+    elseif ty == "key_down" and kba[ka] and ch == 46 and kc == 52 and (modifiers.lalt or modifiers.ralt) then
+     -- next buffer
+     local allBuffers = gpu.buffers()
+     for k,v in ipairs(allBuffers) do
+      if v == vtansi.activeBuffers[gpu.address] and allBuffers[k+1] and not keyboardIgnore[ka] then
+       keyboardIgnore[ka] = bn
+       vtansi.switchToBuffer(gpu,allBuffers[k+1])
+      end
+     end
+    elseif ty == "key_down" and kba[ka] and ch == 44 and kc == 51 and (modifiers.lalt or modifiers.ralt) then
+     -- previous buffer
+     local allBuffers = gpu.buffers()
+     for k,v in ipairs(allBuffers) do
+      if v == vtansi.activeBuffers[gpu.address] and allBuffers[k-1] and not keyboardIgnore[ka] then
+       keyboardIgnore[ka] = bn
+       vtansi.switchToBuffer(gpu,allBuffers[k-1])
+      end
+     end
+    else
+     local outs
+     if ch > 0 then
+      outs = string.char(ch)
+     end
+     outs = vtansi.sequences[kc] or outs
+     if outs then
+      if echo then write(outs) end
+      buf=buf..outs
+     end
+    end
+   end
+  end
+ end,string.format("ttyd[%s:%s/%i]",gpua:sub(1,8),scra:sub(1,8),bn))
+ local function bread(n)
+  coroutine.yield()
+  local r = buf
+  buf = ""
+  return r
+ end
+ local function bwrite(d)
+  local ba, lb, ec = write(d)
+  buf = buf .. ba
+  if lb ~= nil then
+   lbuf = lb
+  end
+  if ec ~= nil then
+   echo = ec
+  end
+ end
+ return bread, bwrite, function() io.write("\27[2J\27[H") end
+end
+return vtansi
diff --git a/multiterm/package.cfg b/multiterm/package.cfg
new file mode 100644
index 0000000..ef59a70
--- /dev/null
+++ b/multiterm/package.cfg
@@ -0,0 +1,4 @@
+{["name"]="multiterm",
+ ["description"]="Patched vtansi and getty to support multiple virtual terminals per display, using video memory",
+ ["authors"]="Izaya",
+ ["system"]=true}
diff --git a/multiterm/service/getty.lua b/multiterm/service/getty.lua
new file mode 100644
index 0000000..ad621b9
--- /dev/null
+++ b/multiterm/service/getty.lua
@@ -0,0 +1,88 @@
+local gpus,screens,ttyn,pids = {}, {}, 0, {}
+local basepid = nil
+local shell = require "shell"
+local vtansi = require "vtansi"
+local function scan()
+ local w,di = pcall(computer.getDeviceInfo)
+ if w then
+  for a,t in pairs(component.list()) do
+   if t == "gpu" then
+    gpus[a] = gpus[a] or {false, tonumber(di[a].capacity)}
+   elseif t == "screen" then
+    screens[a] = screens[a] or {false, tonumber(di[a].capacity)}
+   end
+  end
+ else
+  dprint("no getDevInfo")
+  for a,t in pairs(component.list()) do
+   if t == "gpu" then
+    gpus[a] = gpus[a] or {false, 8000}
+   elseif t == "screen" then
+    screens[a] = screens[a] or {false, 8000}
+   end
+  end
+ end
+end
+local function nextScreen(n)
+ local rt = {}
+ for k,v in pairs(screens) do
+  if not v[1] then
+   rt[v[2]] = rt[v[2]] or k
+  end
+ end
+ return rt[n] or rt[24000] or rt[8000] or rt[4000] or rt[2000] or rt[800] or rt[640] or rt[600]
+end
+
+local function spawnShell(fin,fout)
+ io.input(fin)
+ io.output(fout):setvbuf("no")
+ print(_OSVERSION.." - "..tostring(math.floor(computer.totalMemory()/1024)).."K RAM")
+ print((os.getenv("HOSTNAME") or "unknown") .. " on " .. fin)
+ return os.spawn(function() local w,r = pcall(shell.interactive) if not w then syslog(r) end end, "shell: "..tostring(fin))
+end
+
+local function allocate()
+ for k,v in pairs(gpus) do
+  dprint(k)
+  local sA = nextScreen(v[2])
+  if v[1] == false and sA then
+   component.invoke(k,"freeAllBuffers")
+   component.invoke(k,"bind",sA)
+   local mw, mh = component.invoke(k,"maxResolution")
+   local bufferSize = mw * mh
+   for i = 1, math.floor(component.invoke(k,"totalMemory") / bufferSize) do
+    local r,w = vtansi.vtsession(k,sA,i == 0 and i)
+    devfs.register("tty"..tostring(ttyn), function() return r,w,function() end end)
+    pids["tty"..tostring(ttyn)] = {-1}
+    ttyn = ttyn + 1
+   end
+   gpus[k][1] = true
+   screens[sA][1] = true
+  end
+ end
+end
+
+function start()
+basepid = os.spawn(function()
+scan()
+allocate()
+dprint("screens ready")
+while true do
+ coroutine.yield()
+ for k,v in pairs(pids) do
+  if not os.taskInfo(v[1]) then
+   dprint("Spawning new shell for "..k)
+   pids[k][1] = spawnShell(v[2] or "/dev/"..k, v[3] or "/dev/"..k)
+   pids[k][2], pids[k][3] = pids[k][2] or io.input(), pids[k][3] or io.output()
+   coroutine.yield()
+  end
+ end
+end
+end,"getty")
+return basepid
+end
+function stop()
+ os.kill(basepid)
+ basepid = nil
+end
+return {start=start,stop=stop}