// Example of using the BV4219 as a terminal, this will also
// respond to some VT100 escape codes
// Go word is 'term'

// REQUIRES:
// #URL-lib "http://pin1.org/forthlib/flb/General/soft1.flb" sid=0
// #URL-lib "http://pin1.org/forthlib/flb/General/pinsel.flb" sid=101
// #URL-Lib "http://pin1.org/forthlib/flb/I2C/i2c.flb" sid=102
// #URL-lib "http://pin1.org/forthlib/flb/I2C/bv4219.flb" sid=103

// CONSTANTS:
// set this to the device address
&42 constant dev_address

// utilities
: getnum ( from-key -- number, non-num )
v$: buf 16
int#: bcount 0
    begin
        key dup 48 57 between
    while    
        %@ buf bcount + c!
        1 +> bcount
    repeat    
    0 %@ buf bcount + c! // terminating 0
    %@ buf ?number drop // the -1
;    
// VT100 escape code interpretation
: vt100
int: p1 p2 p3 p4
    key [char] [ <> if drop escape then
    getnum => p1 => p2 // is ; or command 
    p2 [char] ; = if getnum => p3 => p4 then
    p4 [char] H = if p1 p3 a25 then
    p2 [char] A = if a28 p1 - 0 max a8 then // cursor up
    p2 [char] J = if p1 2 = if a5 then then // cls
;    

// check for correct address and if device is present
: device?
    dev_address 4219-init
    if
        400000 i2speed ; // set fast speed
    else
        ." Can't initialise device"
        abort
    then
;            

: term
int: curr_pos
    device? 50 ms
    a5 50 ms // clear screen
    begin    
      key
      dup 27 = if 
        drop vt100
      else  
        dup 3 = if abort then // finish
        dup 13 = if // cr
                a28 7 = 
                if
                    0 0 a25
                else
                    a28 1+ 0 a25
                then     
            then         
        dup 8 = if // bs
            a27 1- 6 / 1- 0 max => curr_pos
            a28 curr_pos a25   50 ms
            32 a20  50 ms // space
            a28 curr_pos a25  50 ms    
            then
        a20
      then  
    again    
;