DCPU16 Text Editor

;6677's Funky Text Editor

;clear function
:clear
SET [0x8000+A], 0
ADD A, 1
IFG A, 0x200
    SET PC, POP
SET PC, clear

:textedit
SET PUSH, A
SET PUSH, B

;Registers A and B can come out to play today, YAY.
;Done for embedding purposes (such as os'es)

;Clear screen first (replace clear with OS clear function if possible)
JSR clear

SET [0x8000], 0xF0DF
SET B, 0
:textedit_loop
SET A, [0x9000]

;check key pressed
IFE A, 0x0
    SET PC, textedit_loop
IFE A, 0x1B
    ;Escape key pressed, quit loop
    SET PC, textedit_exit
IFE A, 0xA
    ;Enter key pressed, move down a row
    SET PC, textedit_newline
IFE A, 8
    ;Backspace pressed
    SET PC, textedit_backspace

IFE A, 1
    SET PC, textedit_left
IFE A, 2
    SET PC, textedit_right
IFE A, 3
    SET PC, textedit_up
IFE A, 4
    SET PC, textedit_down

ADD A, 0xF000
SET [0x8000 + B], A
SET [0x9000], 0x0
ADD B, 1
SET [0x8000 + B], 0xF0DF
SET PC, textedit_loop

:textedit_newline
SET [0x8000 + B], 0x0
SHR B, 5
SHL B, 5
ADD B, 32
SET [0x8000 + B], 0xF0DF
SET [0x9000], 0x0
SET PC, textedit_loop

:textedit_backspace
SET [0x8000 + B], 0x0
SUB B, 1
SET [0x8000 + B], 0xF0DF
SET [0x9000], 0x0
SET PC, textedit_loop

;implement in a future update maybe
:textedit_down
SET [0x9000], 0x0
SET PC, textedit_loop
:textedit_up
SET [0x9000], 0x0
SET PC, textedit_loop
:textedit_left
SET [0x9000], 0x0
SET PC, textedit_loop
:textedit_right
SET [0x9000], 0x0
SET PC, textedit_loop

:textedit_exit
SET POP, B
SET POP, A
;The registers had to go home ):
:textedit_end
;point to allow os'es to skip this program