virtual terminal support with vtansi and getty, for machines with VRAM available

lib/vtansi.lua

@@ -1,4 +1,6 @@
 local vtansi = {}
+local keyboardIgnore = {}
+vtansi.activeBuffers = {}
 vtansi.sequences = {
  [28] = "\n", -- newline
  [200] = "\27[A", -- up
@@ -8,9 +10,26 @@ vtansi.sequences = {
  [201] = "\27[5~", -- page up
  [209] = "\27[6~" -- page down
 }
-function vtansi.vtemu(gpu) -- table -- function -- takes GPU component proxy *gpu* and returns a function to write to it in a manner like an ANSI terminal
+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 buffer = nil
  local cx, cy = 1, 1
  local pc = " "
  local lc = ""
@@ -21,8 +40,19 @@ function vtansi.vtemu(gpu) -- table -- function -- takes GPU component proxy *gp
  local bg, fg = 0, 0xFFFFFF
 
  -- setup
+ if gpu.getActiveBuffer then
+  buffer = bn or gpu.allocateBuffer(mx,my)
+  vtansi.activeBuffers[gpu.address] = vtansi.activeBuffers[gpu.address] or buffer
+  local oldActiveBuffer = vtansi.activeBuffers[gpu.address]
+  gpu.setActiveBuffer(buffer)
   gpu.setResolution(mx,my)
   gpu.fill(1,1,mx,my," ")
+  gpu.setActiveBuffer(oldActiveBuffer)
+ else
+  gpu.setResolution(mx,my)
+  gpu.fill(1,1,mx,my," ")
+ end
+
  local function checkCursor()
   if cx > mx and lw then
    cx, cy = 1, cy+1
@@ -37,6 +67,13 @@ function vtansi.vtemu(gpu) -- table -- function -- takes GPU component proxy *gp
  end
 
  local function termwrite(s)
+  if buffer then
+   if vtansi.activeBuffers[gpu.address] == buffer then
+    gpu.setActiveBuffer(0)
+   else
+    gpu.setActiveBuffer(buffer)
+   end
+  end
   local wb = ""
   local lb, ec = nil, nil
   local function flushwb()
@@ -161,13 +198,14 @@ function vtansi.vtemu(gpu) -- table -- function -- takes GPU component proxy *gp
   return rs, lb, ec
  end
 
- return termwrite
+ return termwrite, buffer
 end
 
-function vtansi.vtsession(gpua,scra) -- string string -- table -- creates a process to handle the GPU and screen address combination *gpua*/*scra*. Returns read, write and "close" functions.
+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)
+-- gpu.bind(scra)
- local write = vtansi.vtemu(gpu)
+ local write, bn = vtansi.vtemu(gpu,bn)
  local kba = {}
  for k,v in ipairs(component.invoke(scra,"getKeyboards")) do
   kba[v]=true
@@ -176,7 +214,32 @@ function vtansi.vtsession(gpua,scra) -- string string -- table -- creates a proc
  os.spawn(function()
   while true do
    local ty,ka,ch,kc = coroutine.yield()
-   if ty == "key_down" and kba[ka] then
+   if kba[ka] and 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 (bn == nil or vtansi.activeBuffers[gpua] == bn) then
+    if bn and 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 bn and 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)
@@ -188,7 +251,8 @@ function vtansi.vtsession(gpua,scra) -- string string -- table -- creates a proc
      end
     end
    end
- end,string.format("ttyd[%s:%s]",gpua:sub(1,8),scra:sub(1,8)))
+  end
+ end,string.format("ttyd[%s:%s/%i]",gpua:sub(1,8),scra:sub(1,8),tonumber(bn) or 0))
  local function bread(n)
   coroutine.yield()
   local r = buf

service/getty.lua

@@ -37,21 +37,33 @@ local function spawnShell(fin,fout)
  io.input(fin)
  io.output(fout):setvbuf("no")
  print(_OSVERSION.." - "..tostring(math.floor(computer.totalMemory()/1024)).."K RAM")
- return os.spawn(function() local w,r = pcall(shell.interactive) if not w then syslog(r) end end, "shell: "..tostring(fin))
+ 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))
+ return os.spawn(shell.interactive, "shell: "..tostring(fin))
 end
 
 local function allocate()
  for k,v in pairs(gpus) do
-  dprint(k)
+  dprint("Setting up display "..k)
   local sA = nextScreen(v[2])
   if v[1] == false and sA then
+   local terminals = 1
+   local gpu = component.proxy(k)
+   gpu.bind(sA)
+   if gpu.buffers then
+    gpu.freeAllBuffers()
+    local mw, mh = gpu.maxResolution()
+    terminals = math.floor(gpu.freeMemory() / (mw * mh))
+   end
+   for i = 1, terminals do
     local r,w = vtansi.vtsession(k,sA)
     devfs.register("tty"..tostring(ttyn), function() return r,w,function() end end)
-   gpus[k][1] = true
-   screens[sA][1] = true
     pids["tty"..tostring(ttyn)] = {-1}
     ttyn = ttyn + 1
    end
+   gpus[k][1] = true
+   screens[sA][1] = true
+  end
  end
 end
 
@@ -59,14 +71,15 @@ function start()
 basepid = os.spawn(function()
 scan()
 allocate()
-dprint("screens ready")
+dprint("Display setup complete.")
 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()
+   pids[k][2], pids[k][3] = pids[k][2] or "/dev/"..k, pids[k][3] or "/dev/"..k
+   coroutine.yield()
   end
  end
 end