added an embeddable VT100 emulator

Embedded/vt100.lua

@@ -0,0 +1,114 @@
+function vt100emu(gpu)
+ local mx, my = gpu.maxResolution()
+ local cx, cy = 1, 1
+ local pc = " "
+ local lc = ""
+ local mode = "n"
+ local lw = true
+ local sx, sy = 1,1
+ local cs = ""
+
+ -- setup
+ gpu.setResolution(mx,my)
+ gpu.fill(1,1,mx,my," ")
+
+ local function dcursor()
+  pc = gpu.get(cx,cy)
+  gpu.setForeground(0)
+  gpu.setBackground(0xFFFFFF)
+  gpu.set(cx,cy,pc)
+  gpu.setForeground(0xFFFFFF)
+  gpu.setBackground(0)
+ end
+ local function udcursor()
+  pc = gpu.get(cx,cy)
+  gpu.setForeground(0xFFFFFF)
+  gpu.setBackground(0)
+  gpu.set(cx,cy,pc)
+ end
+
+ function termwrite(s)
+  s=s:gsub("\8","\27[D")
+  udcursor()
+  for i = 1, s:len() do
+   local cc = s:sub(i,i)
+
+   if mode == "n" then
+    if cc == "\n" then -- line feed
+     cx, cy = 1, cy+1
+    elseif cc == "\r" then -- cursor home
+     cx = 1
+    elseif cc == "\27" then -- escape
+     mode = "e"
+    elseif string.byte(cc) > 31 and string.byte(cc) < 127 then -- printable, I guess
+     gpu.set(cx, cy, cc)
+     cx = cx + 1
+    end
+
+   elseif mode == "e" then
+    if cc == "[" then
+     mode = "v"
+     cs = ""
+    elseif cc == "D" then -- scroll down
+     gpu.copy(1,2,mx,my-1,0,-1)
+     gpu.fill(1,my,mx,1," ")
+     cy=cy+1
+     mode = "n"
+    elseif cc == "M" then -- scroll up
+     gpu.copy(1,1,mx,my-1,0,1)
+     gpu.fill(1,1,mx,1," ")
+     mode = "n"
+    end
+
+   elseif mode == "v" then -- save cursor
+    local n = cs:sub(cs:len(),cs:len())
+    if n == "" then n = "\1" end
+    if cc == "s" then
+     sx, sy = cx, cy
+     mode = "n"
+    elseif cc == "u" then -- restore cursor
+     cx, cy = sx, sy
+     mode = "n"
+    elseif cc == "H" then -- cursor home or to
+     local tx, ty = cs:match("(.);(.)")
+     tx, ty = tx or "\1", ty or "\1"
+     cx, cy = string.byte(tx), string.byte(ty)
+     mode = "n"
+    elseif cc == "A" then -- cursor up
+     cy = cy - string.byte(n)
+     mode = "n"
+    elseif cc == "B" then -- cursor down
+     cy = cy + string.byte(n)
+     mode = "n"
+    elseif cc == "C" then -- cursor right
+     cx = cx + string.byte(n)
+     mode = "n"
+    elseif cc == "D" then -- cursor left
+     cx = cx - string.byte(n)
+     mode = "n"
+    elseif cc == "h" and lc == "7" then -- enable line wrap
+     lw = true
+    elseif cc == "l" and lc == "7" then -- disable line wrap
+     lw = false
+    end
+    cs = cs .. cc
+   end
+
+   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
+
+   lc = cc
+  end
+  dcursor()
+ end
+
+ return termwrite
+end