View difference between Paste ID: wbwZ6xWy and 52NwefB9

-p_HorizLine:
+p_HLine:
-	.db __HorizLineEnd-$-1
+	.db __HLineEnd-$-1
 	ld	de,plotSScreen
 x_HLineEntry:
-x_HorizLineEntry:
+
-;; de=buff, hl=x2, (sp)=ret, (sp+2)=x1, (sp+4)=y
+;; de=buff, l=x2, (sp)=ret, (sp+2)=x1, (sp+4)=y
-	pop	af
+;; Rearrange stuff
 	ld	a,l
-	ld	h,c
+	pop	hl
 	pop	bc
-	push	af
+	ex	(sp),hl
 
-;; c=y, de=buff, h=x1, l=x2
+;; a=x2, c=x1, de=buff, l=y
-;; Check if x1 is offscreen left; if so, note and fix it
+;; Check if x2 is offscreen left; if so, note and fix it
-	ld	b,0
+	ld	h,0
-	ld	a,h
+
 	rla
 	jr	nc,$+3
-	ld	h,b
+	ld	b,h
 
-;; carry=x1 offscreen, b=0, c=y, de=buff, h=left-fixed x1, l=x2
+;; carry=x2 offscreen, b=left-fixed x2, c=x1, de=buff, h=0, l=y
-;; Check if x2 is offscreen left; if so, abort if x1 was too, then fix it
+;; Check if x1 is offscreen left; if so, abort if x2 was too, then fix it
-	bit	7,l
+	bit	7,c
 	jr	z,$+4
 	ret	c
-	ld	l,b
+	ld	c,h
 
-;; b=0, c=y, de=buff, h=left-fixed x1, l=left-fixed x2
+;; b=left-fixed x2, c=left-fixed x1, de=buff, h=0, l=y
-;; Check if x1 is offscreen right, and if so, abort if x2 is too, then fix it
+;; Check if x1 is offscreen right; if so, abort if x2 is too, then fix it
 	ld	a,95
-	cp	h
+	cp	c
 	jr	nc,$+5
-	cp	l
+	cp	b
-	ret	nc
+
-	ld	h,a
+
 
-;; a=95, b=0, c=y, de=buff, h=fixed x1, l=left-fixed x2
+;; a=95, b=left-fixed x2, c=fixed x1, de=buff, h=0, l=y
-;; Check if x2 is offscreen right, and if so, fix it
+;; Check if x2 is offscreen right; if so, fix it
-	cp	l
+	cp	b
 	jr	nc,$+3
-	ld	l,a
+
 
 ;; X Clipping complete; x1 and x2 guaranteed to be onscreen
-;; a=95, b=0, c=y, de=buff, h=x1, l=x2
+;; a=95, b=x2, c=x1, de=buff, h=0, l=y
-;; Ensure that x1<=x2
+;; Locate the lesser and greater (will refer to them as x1 and x2) of x1 and x2
-	ld	a,h
+	ld	a,b
-	cp	l
+	cp	c
 	jr	c,$+5
 	ld	c,b
-	ld	l,h
+
-	ld	h,a
+	ld	a,c
 
-x_HorizLineEntry2:
+;; a=x1, b=x1, c=x2, de=buff, h=0, l=y
-;; a=x1, b=0, c=y, de=buff, h=x1, l=x2
+;; Abort if y is offscreen while calculating y*4
-;; Abort if y is offscreen, add y*12 to buffer, and add x1/8 to buffer
+	add	hl,hl
-;;   y is rotated left while x1 is rotated right so rra can be used for x1
+	add	hl,hl
-	sla	c
+	dec	h
 	ret	m
 	inc	h
-	sla	c
+
 ;; a=x1, b=x1, c=x2, de=buff, h=0, l=y*4
 ;; Calculate x1/8 and add it and y*12 to the buffer pointer
 	ex	de,hl
-	add	hl,bc
+	add	hl,de
 	rra
-	add	hl,bc
+	add	hl,de
-	add	hl,bc
+
 	add	hl,de
-	add	hl,bc
+
 	ld	e,a
-;; y no longer needed
+	add	hl,de
-;; a=x1/8, b=0, c=x1/8, d=x1, e=x2, hl=y*12+(x/8)+buff
+
-	ld	c,7
+;; Begin drawing! y no longer needed
-	ld	a,d
+;; a=x1/8, b=x1, c=x2, d=0, e=x1/8, hl=y*12+(x1/8)+buff
-	and	c
+;; Calculate the mask for the first byte
-	jr	z,__HorizLineLeft8
+	ld	e,b
 	ld	a,b
-	ld	a,1
+	and	%00000111
-__HorizLineLeftLoop:
+	jr	z,__HLineLeft8
 	ld	b,a
-	djnz	__HorizLineFirstLoop
+	ld	a,$01
-__HorizLineLeft8:
+__HLineLeftLoop:
 	rrca
 	djnz	__HLineFirstLoop
 __HLineLeft8:
-	ld	a,d
+
-	or	c
+
-	inc	c
+;; a=first mask, b=0, c=x2, d=0, e=x1, hl=y*12+(x1/8)+buff
-	sub	e
+;; Prepare the first byte and calculate the negative remaining width after the
-	jr	c,__HorizLineRight	;???
+;;   first byte; if positive, jump to the masking code for the last byte
-__HorizLineMidLoop:
+
-	ld	(hl),b
+	ld	d,a
 	ld	a,e
-	ld	b,$FF
+	or	%00000111
 	sub	c
-	jr	nc,__HorizLineMidLoop
+	jr	nc,__HLineRight
-__HorizLineRight:
+
-	add	a,c	;???
+;; a=-width remaining, b=0, c=x2, d=byte, e=x1, hl=y*12+(x1/8)+buff
-	ret	z	;???
+;; Draw bytes until there is no width remaining
 __HLineMidLoop:
-	ld	a,1
+	ld	(hl),d
-__HorizLineRightLoop:
+
 	ld	d,$FF
-	djnz	__HorizLineRightLoop
+	add	a,8
 	jr	nc,__HLineMidLoop
-	and	b
+
 ;; a=width remaining-1%8+1, b=0, c=x2, d=byte, e=x1, hl=y*12+(x2/8)+buff
 ;; Calculate the mask for the last byte
 __HLineRight:
-__HorizLineEnd:
+
 	inc	b
 	ld	a,$80
 __HLineRightLoop:
 	rlca
 	djnz	__HLineRightLoop
 	dec	a
 	cpl
 
 ;; a=mask, b=0, c=x2, d=byte, e=x1, hl=y*12+(x2/8)+buff
 ;; Draw the last byte
 	and	d
 	or	(hl)
 	ld	(hl),a
 
 	ret
 __HLineEnd: