From fc127f8d3e822966002a974b81e105cae717c027 Mon Sep 17 00:00:00 2001
From: XeonSquared <redtailedairways@gmail.com>
Date: Sun, 12 Apr 2020 01:59:56 +1000
Subject: [PATCH] moved the VT100 driver out of the kernel and into its own
 library

---
 lib/vtansi.lua    | 197 ++++++++++++++++++++++++++++++++++++++++++++++
 module/init.lua   |   1 -
 service/getty.lua |   3 +-
 3 files changed, 199 insertions(+), 2 deletions(-)
 create mode 100644 lib/vtansi.lua

diff --git a/lib/vtansi.lua b/lib/vtansi.lua
new file mode 100644
index 0000000..d5a247f
--- /dev/null
+++ b/lib/vtansi.lua
@@ -0,0 +1,197 @@
+local vtansi = {}
+function vtansi.vtemu(gpu) -- takes GPU component proxy *gpu* and returns a function to write to it in a manner like an ANSI terminal
+ 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
+
+ -- 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
+
+ local function termwrite(s)
+  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
+    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 = tA[1] or 1, tA[2] or 1
+     elseif cc == "A" then
+      cy = cy - (tA[1] or 1)
+     elseif cc == "B" then
+      cy = cy + (tA[1] or 1)
+     elseif cc == "C" then
+      cx = cx + (tA[1] or 1)
+     elseif cc == "D" then
+      cx = cx - (tA[1] or 1)
+     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)
+     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,true,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 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
+end
+
+function vtansi.vtsession(gpua,scra) -- creates a process to handle the GPU and screen address combination *gpua*/*scra*. Returns read, write and "close" functions.
+ local gpu = component.proxy(gpua)
+ gpu.bind(scra)
+ local write = vtansi.vtemu(gpu)
+ local kba = {}
+ for k,v in ipairs(component.invoke(scra,"getKeyboards")) do
+  kba[v]=true
+ end
+ local buf, lbuf, echo = "", true, true
+ os.spawn(function() dprint(pcall(function()
+  while true do
+   local ty,ka,ch = coroutine.yield()
+   if ty == "key_down" and kba[ka] then
+    if ch == 13 then ch = 10 end
+    if ch == 8 and lbuf then
+     if buf:len() > 0 then
+      if echo then write("\8 \8") end
+      buf = buf:sub(1,-2)
+     end
+    elseif ch > 0 then
+     if echo then write(string.char(ch)) end
+     buf=buf..string.char(ch)
+    end
+   end
+  end
+ end)) end,string.format("ttyd[%s:%s]",gpua:sub(1,8),scra:sub(1,8)))
+ local function bread(n)
+  local r
+  if lbuf then
+   while not buf:find("\n") do
+    coroutine.yield()
+   end
+   local n = buf:find("\n")
+   r, buf = buf:sub(1,n), buf:sub(n+1)
+  else
+   r = buf
+   buf = ""
+   coroutine.yield()
+  end
+  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/module/init.lua b/module/init.lua
index aa9cc11..08b4fe8 100644
--- a/module/init.lua
+++ b/module/init.lua
@@ -7,7 +7,6 @@
 --#include "module/devfs.lua"
 --#include "module/devfs/syslog.lua"
 --#include "module/loadfile.lua"
---#include "module/vt-task.lua"
 
 os.spawn(function()
  os.setenv("PWD","/boot")
diff --git a/service/getty.lua b/service/getty.lua
index 0c5797c..6c71b6c 100644
--- a/service/getty.lua
+++ b/service/getty.lua
@@ -1,6 +1,7 @@
 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
@@ -44,7 +45,7 @@ local function allocate()
   dprint(k)
   local sA = nextScreen(v[2])
   if v[1] == false and sA then
-   local r,w = vtemu(k,sA)
+   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