From 6bad8fa605f5011cadab428156c18b4067922185 Mon Sep 17 00:00:00 2001
From: mrb0nk500 <b0nk@b0nk.xyz>
Date: Tue, 24 Mar 2020 18:46:44 -0400
Subject: Added support in SuBEditor for true backspace, and inserting
 characters without replacing the old ones.

---
 programs/subeditor.s | 191 ++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 160 insertions(+), 31 deletions(-)

(limited to 'programs/subeditor.s')

diff --git a/programs/subeditor.s b/programs/subeditor.s
index 5769936..1001f83 100644
--- a/programs/subeditor.s
+++ b/programs/subeditor.s
@@ -46,6 +46,8 @@ scr_tcol:
 	.byte $0
 scr_ptr:
 	.word $0
+scr_ptr2:
+	.word $0
 ; Registers.
 a:
 	.byte $0
@@ -151,6 +153,8 @@ start:
 	tay
 	jsl clr_cbuf
 	ply #2
+	;lda #1
+	;sta $C010
 	lda.w #string
 	jsl print_str
 	lda.w zero
@@ -204,6 +208,8 @@ print_str:
 	sta.q ptr
 	ldb #0
 	tba
+	inb
+	stb b
 pntstr_st:
 	phy #2
 	txy
@@ -215,6 +221,8 @@ pntstr_st:
 	jmp pntstr_st
 pntstr_end:
 	ply #2
+	ldb #0
+	stb b
 	rtl
 
 
@@ -278,6 +286,7 @@ getchar:
 	lda $C002	; Get typed character.
 	ldb #0
 	stb e
+	stb b
 	pha #1
 	phy #2
 	cmp #10
@@ -363,8 +372,72 @@ print_char:
 	beq bs		; Did the user type a backspace?
 	sta a
 printc:
+	lda (ptr5), y	; Are we at the end of the string?
+	beq printc_save	; Yes, so just print the character.
+	lda b		; No, but was the flag set?
+	bne printc_save	; Yes, so don't shift the line.
+	sty.w scr_ptr	; No, so save the cursor index for later.
+prntc_fndnd:
+	lda (ptr5), y	; Are we at the end of the string?
+	beq prntc_movln	; Yes, so make room for the next character.
+	iny		; No, so increment the cursor index.
+	jmp prntc_fndnd	; Keep looping.
+printc_updt:
+	jmp prntc_updt2
+prntc_updt1:
+	pla #1
+	clc
+	adc scr_row
+	sta scr_row
+	jsl update_pos
+prntc_updt2:
+	lda scr_row
+	pha #1
+	lda scr_col
+	pha #1
+	jsl rdrw_row
+	pla #1
+	sta scr_col
+	pla #1
+	sta scr_row
+	jsl update_pos
+prntc_updt3:
+	ldb scr_row
+	lda scr_trow
+	sec
+	sab
+	pha #1
+	tab
+	sec
+	sab
+	clc
+	sta scr_row
+prntc_updt4:
+	jsl getbit
+	bcs prntc_updt1
+	pla #1
+	lda scr_trow
+	sta scr_row
+	jsl update_pos
+	dec d
+	jmp printc_sav1
+prntc_movln:
+	tyx
+	dey
+	ldb #1
+	stb d
+	jsl shftln
+	ldb #1
+	stb d
+	lda scr_row
+	sta scr_trow
+printc_save:
+	ldb d
+	bne printc_updt
+printc_sav1:
 	lda a
 	sta (ptr5), y	; Store typed character into the input buffer.
+printc_inc:
 	inc scr_col	; Increment the cursor's x coordinate.
 	iny
 printc_2:
@@ -414,7 +487,10 @@ printc_end:
 
 nl:
 	lda #0
+	ldb (ptr5), y
+	bne nl1
 	sta (ptr5), y	; Store said terminator into the input buffer.
+nl1:
 	sta scr_col
 	lda scr_row
 	cmp #23
@@ -468,11 +544,16 @@ stp_end:
 	jmp printc_end
 
 back:
-	lda #$7F	; Print a backspace to the screen.
-	sta $C001	;
 	dey		; Decrement the buffer's offset.
 	lda #0		; Place a null terminator
 	sta (ptr5), y	; into the buffer.
+	tyx		; Copy the current cursor index to X.
+	iny		; Increment cursor index.
+	ldb #0
+	stb d
+	jsl shftln	; Move/Shift line back by one character.
+	lda #$7F	; Print a backspace to the screen.
+	sta $C001	;
 	dec scr_col	; Move the cursor back by one column,
 	jsl update_pos	; and update it's position.
 	jmp printc_end	; We are done.
@@ -510,6 +591,49 @@ backwrp2:
 	jsl update_pos	; Update the cursor's position.
 	jmp back	; Delete the previous character.
 
+shftln:
+	ldb d		; Is the flag set?
+	beq shftln_lp1	; Yes, so shift, and increment.
+	jmp shftln_lp0	; No, so shift, and decrement.
+shftln_neg:
+	ldy.w zero	; Set the source poition to 0.
+	lda #0		; Clear the character
+	sta (ptr5), y	; that is in the source.
+	jmp shftln_end	; We are done.
+shftln_lp0:
+	sty.w scr_ptr2	; Save the source position for later.
+	ldy.w scr_ptr	; Get the previous cursor index.
+	cpy.w scr_ptr2	; Is the source position, at, or below the cursor index?
+	beq shftln_lp01	; Yes, so keep looping.
+	bcs shftln_end	; No, so we're done.
+shftln_lp01:
+	ldy.w scr_ptr2	; Get the source position.
+	lda (ptr5), y	; Get the character from the source position.
+	phy #2		; Save the source position for later.
+	txy		; Set our position to the destination.
+	sta (ptr5), y	; Place the character from the source position, to the destination position.
+	ply #2		; Set our position back to the source.
+	lda #0		; Clear the character
+	sta (ptr5), y	; that is in the source.
+	dey		; Decrement the source position.
+	bng shftln_neg	; The source underflowed, so set it back to zero,
+	dex		; Decrement the destination position.
+	jmp shftln_lp0	; Keep looping.
+shftln_lp1:
+	lda (ptr5), y	; Is the character at the source position, a null terminator?
+	beq shftln_end	; Yes, so we're done.
+	phy #2		; No, so save the source position for later.
+	txy		; Set our position to the destination.
+	sta (ptr5), y	; Place the character from the source position, to the destination position.
+	inx		; Increment the destination position.
+	ply #2		; Set our position back to the source.
+	lda #0		; Clear the character
+	sta (ptr5), y	; that is in the source.
+	iny		; Increment the source position.
+	jmp shftln_lp1	; Keep looping.
+shftln_end:
+	rtl		; We are done.
+
 esc:
 	lda $C000	; Get the next character.
 	lda $C002	;
@@ -611,8 +735,8 @@ isright_wrp:
 	dec scr_row	; No, so move the cursor back up a row.
 	jmp isright_dne	; We are done.
 isright_scr:
-	lda scr_str	; Are we at the top of the screen buffer?
-	beq isright_end	; Yes, so we're done.
+;	lda scr_str	; Are we at the top of the screen buffer?
+;	beq isright_end	; Yes, so we're done.
 	lda #1		; No, so scroll down.
 	sta wrapped	; Set the wrapped flag.
 	jsl scrl_down	; Scroll down.
@@ -622,6 +746,7 @@ wrap_inc:
 	sta scr_col	;
 	lda scr_row	; Get the current row number.
 	cmp #23		; Are we at the bottom of the screen?
+	beq isright_nd2	; No, so we're done.
 	bcs isright_scr	; Yes, so check if we are scrolling down.
 	jmp isright_nd2	; We are done.
 isright_end:
@@ -741,8 +866,13 @@ update_pos:
 	clc
 	lda scr_row
 	adc scr_str
+	tay
 	clc
-	mul #80
+	lsl #6
+	tab
+	tya
+	lsl #4
+	aab
 	clc
 	adc scr_col
 	tay
@@ -781,7 +911,6 @@ getcol:
 	rtl		; End of getrow.
 
 scrl_down:
-
 	inc scr_str
 	inc scr_end
 	lda #$1B	; Print an escape character
@@ -851,14 +980,16 @@ rdrow_inc:
 	inc scr_col
 	lda (ptr5), y
 	beq rdrow_skip
-	iny
 rdrow_inc1:
+	iny
+rdrow_inc2:
 	lda scr_col
 	cmp #80
 	bcs rdrow_end
 	jmp rdrow_st
 rdrow_skip:
-	jsl update_pos
+	lda #$20
+	sta $C001	; to the screen.
 	jmp rdrow_inc1
 rdrow_end:
 	lda #0
@@ -867,26 +998,32 @@ rdrow_end:
 rdrow_done:
 	rtl
 
-
 ;rdrw_scr:
-;	lda #$C
-;	sta $C001
-;	lda scr_col
-;	sta scr_tcol
 ;	lda scr_row
-;	sta scr_trow
+;	sta e
 ;	lda #0
-;	sta scr_col
 ;	sta scr_row
-;	phy #2
+;	lda scr_col
+;	sta f
+;	jsl update_pos
+;rdscr_st:
+;	jsl rdrw_row
+;	lda scr_row
+;	cmp #23
+;	beq rdscr_inc
+;	bcs rdscr_done
+;rdscr_inc:
+;	inc scr_row
+;	jmp rdscr_st
+;rdscr_done:
+;	lda e
+;	sta scr_row
+;	lda f
+;	sta scr_col
 ;	jsl update_pos
-;	ply #2
-;	ldx scr_ptr
-;	phy #2
-;	txy
-;	lda (ptr), y
-;	sta $C001
-;	ply #2
+;	lda #0
+;	sta e
+;	sta f
 ;	rtl
 
 result:
@@ -945,14 +1082,6 @@ cmd_clr:
 .org $FFC0
 .qword reset
 
-.org $FF50
-.qword spin
-.qword spin
-.qword spin
-.qword spin
-.qword spin
-.qword spin
-.qword spin
 r
 ;.org $8000
 ;v
-- 
cgit v1.2.3-13-gbd6f