termbox janet bindings

These are essentially complete, tb_put_cell and tb_blit are the only unimplemented termbox functions.

(import jtermbox :as tb)

(defn main [& args]
  (tb/init)
  (tb/clear)

  (tb/put-string 0 0 "type to see events. ctrl-c to quit")
  (tb/present)

  (while true
    (def ev (tb/poll-event))
    (tb/put-string 0 1 (string/format "%j" ev))
    (case (ev :type)
      "key" (case (ev :key)
              "ctrl-c" (break)))
    (tb/present))

  (tb/shutdown))

It sticks to the termbox API as much as possible, with keywords used in place of constants. Two extra utility functions are provided, color to create colors and put-string to draw strings.

functions

(init)
  initialize the termbox library.
  must be called before any other functions.
  
(shutdown)
  restore the terminal to it's initial state.

(clear)
  clear the internal terminal buffer.

(set-clear-attributes fg bg)
  set the attributes used when clearing the screen with clear.

(change-cell x y ch &opt fg bg)
  change a cell in the internal bufffer at the specified position.
  fg and bg default to (tb/color :default).
  
(put-string x y str &opt fg bg)
  draw a string at x, y.
  fg and bg default to (tb/color :default).

(color & kws)
  create a termbox color. accepts a color followed by any number of modifiers.
  
  valid keywords are :default :black :red :green :yellow :blue :magenta :cyan
  :white :bold :underline :reverse
  
  in 256 color, 216 color and grayscale modes, use numbers rather than keywords
  to select colors.

(present)
  sync the internal buffer with the terminal.

(height)
  return the height of the terminal

(width)
  return the width of the terminal

(poll-event)
  wait for an event and return it.
  there are three types of event.
  
  key events, which contain either a character or a key name:
  @{:type "key" :ch "a" :key "arrow-down" :mod "alt"}
  
  resize events, which contain a width and height:
  @{:type "resize" :w 640 :h 480}
  
  and mouse events, which contain x and y co-ordinates:
  @{:type "mouse" :x 20 :y 60 :mod "motion"}
  
(peek-event timeout)
  wait for an event up to timeout milliseconds.
  returns the event, or nil if no event happened before the timeout.
  
  see poll-event for info on the returned value.

(select-output-mode)
  set the output mode.
  valid modes are :normal :256 :216 :grayscale and :current.
  when called with :current, will return the current mode as a keyword.
  
(select-input-mode)
  set the input mode.
  valid modes are :current :esc :alt :mouse.
  when called with :current, will return the current mode as a keyword.

(set-cursor cx cy)
  set the position of the cursor. pass -1 for both cx and cy to hide the cursor.

events

The result from (poll-event) can be one of three things.

Key events, which contain either a character or a key name:

@{:type "key" :ch "a" :key "arrow-down"}

Resize events, which contain a width and height:

@{:type "resize" :w 640 :h 480}

Mouse events, which contain x and y co-ordinates:

@{:type "mouse" :x 20 :y 60}