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|
; asm rewrites of functions originally written in C, for edbox.c.
; old C code here as comments, for reference.
.export _edbox_addchr, _edbox_space, _edbox_set, _edbox_clear
.export _hide_cursor, _show_cursor, _storechr
.export _copy_to_old, _restore_old, _backspace, _inschr
.import _edbox_len, _edbox_pos, _old_edbox, _old_len, _typeover
.import _del_char, _bell, _move_right
.importzp ptr1
; EDBOX_SIZE + 1, see edbox.h
EDBOX_SIZE_PLUS_1 = $f1
EDBOX_SIZE = $f0
EDBOX_MAXPOS = $ef
EDBOX_ADDR = $0600 ; MUST agree with EDBOX_ADDR from addrs.h!
; this compiled to like 31 bytes of code...
; this version is 7 bytes.
;; void storechr(char c) {
;; edit_box[edbox_pos] = c;
;; }
_storechr:
ldx _edbox_pos
sta EDBOX_ADDR,x
rts
;; void hide_cursor(void) {
;; edit_box[edbox_pos] &= 0x7f;
;; }
_hide_cursor:
ldx _edbox_pos
lda EDBOX_ADDR,x
and #$7f
store_curs:
sta EDBOX_ADDR,x
rts
;; void show_cursor(void) {
;; edit_box[edbox_pos] |= 0x80;
;; }
_show_cursor:
ldx _edbox_pos
lda EDBOX_ADDR,x
ora #$80
bne store_curs
;; static void copy_to_old(void) {
;; if(!edbox_len) return;
;; memcpy(old_edbox, edit_box, edbox_len);
;; bzero(old_edbox + edbox_len, EDBOX_MAXPOS - edbox_len);
;; old_len = edbox_len;
;; }
_copy_to_old:
lda _edbox_len
beq nope
ldx #0
@l:
lda EDBOX_ADDR,x
sta _old_edbox,x
inx
cpx #EDBOX_SIZE
bne @l
lda _edbox_len
sta _old_len
nope:
rts
;; static void restore_old(void) {
;; edbox_clear();
;; hide_cursor();
;; memcpy(edit_box, old_edbox, old_len);
;; edbox_pos = edbox_len = old_len;
;; }
_restore_old:
lda _old_len
beq nope
ldx #0
@l:
lda _old_edbox,x
sta EDBOX_ADDR,x
inx
cpx #EDBOX_SIZE
bne @l
lda _old_len
sta _edbox_len
sta _edbox_pos
rts
;; static void backspace(void) {
;; if(!edbox_pos) return;
;; edbox_pos--;
;; if(typeover)
;; edit_box[edbox_pos] = ' ';
;; else
;; del_char();
;; }
_backspace:
lda _edbox_pos
beq @nope
dec _edbox_pos
lda _typeover
bne @spc
jmp _del_char
@spc:
lda #$20
ldx _edbox_pos
sta EDBOX_ADDR,x
@nope:
rts
;; void inschr(char c) {
;; if(edbox_len == EDBOX_MAXPOS) {
;; /* buffer full, can't insert */
;; bell();
;; return;
;; }
;; move_right();
;; edbox_len++;
;; storechr(c);
;; edbox_pos++;
;; }
_inschr:
pha
lda _edbox_len
cmp #EDBOX_MAXPOS
bne @ok
pla
jmp _bell
@ok:
jsr _move_right
inc _edbox_len
pla
jsr _storechr
inc _edbox_pos
rts
;; void edbox_clear(void) {
;; bzero(edit_box, EDBOX_SIZE + 1);
;; edbox_pos = edbox_len = 0;
;; show_cursor(); // not needed? seems it is..
;; }
_edbox_clear:
ldx #0
txa
@l:
sta EDBOX_ADDR,x
inx
cpx #EDBOX_SIZE_PLUS_1
bne @l
sta _edbox_pos
sta _edbox_len
jmp _show_cursor
;; void edbox_space(void) {
;; edbox_addchr(' ');
;; }
_edbox_space:
lda #$20
; fall thru...
;; void edbox_addchr(char c) {
;; edit_box[edbox_len++] = c;
;; edbox_pos = edbox_len;
;; }
_edbox_addchr:
ldx _edbox_len
sta EDBOX_ADDR,x
inx
stx _edbox_len
stx _edbox_pos
rts
;; void edbox_set(char *contents) {
;; edbox_clear();
;; while(*contents) {
;; edit_box[edbox_len++] = *contents++;
;; }
;; edbox_pos = edbox_len;
;; }
; notice the asm version does bounds checking, which the C version
; didn't do.
_edbox_set:
sta ptr1
stx ptr1+1
jsr _edbox_clear
ldy #0
@l:
lda (ptr1),y
sta EDBOX_ADDR,y
beq @done ; if we hit a 0 byte in the input, we're done
inx
iny
cpy #EDBOX_SIZE_PLUS_1 ; if we hit the edbox size limit, we're done
bne @l
dey
@done:
sty _edbox_len
sty _edbox_pos
rts
|
