spiral: update code comments

demos/lovebyte2024/spiraling_shape_32/spiral_32.s

@@ -10,10 +10,13 @@
 GBASL		=	$26
 GBASH		=	$27
 HGR_SCALE	=	$E7
-HGR_COLLISION	=	$EA
+HGR_COLLISION	=	$EA		; overlaps our code, but it's OK
+					; as it's modified after the HGR2
+					; runs
 
 HGR_ROTATION	=	$FE		; IMPORTANT! set this right!
-
+					; we get this for free by loading
+					; our code into $E9 in zero page
 ; ROM locations
 HGR2		=	$F3D8
 HPOSN		=	$F411
@@ -29,10 +32,14 @@ spiraling_shape:
 	; X is left behind by the boot process?
 
 tiny_loop:
-	bit	$C030
+	bit	$C030		; click the speaker for some sound
+
 	tay	; ldy #0		; A always 0 here
-	ldx	#140
-	lda	#96
+
+	ldx	#140		; center spiral on the screen
+				; this is expensive
+	lda	#96		; but otherwise doesn't look right
+
 	jsr	HPOSN		; set screen position to X= (y,x) Y=(a)
 				; saves X,Y,A to zero page
 				; after Y= orig X/7
@@ -40,21 +47,33 @@ tiny_loop:
 
 	ldx	#<our_shape		; load $E2DF
 	ldy	#>our_shape		;
-	inc	HGR_ROTATION
+	inc	HGR_ROTATION	; rotate the line, also make it larger
 
 	lda	#1		; HGR_ROTATION is HERE ($FE)
+				; we also use it for scale
 
 	and	#$7f		; cut off before it gets too awful
 	sta	HGR_SCALE
 
 	jsr	XDRAW0		; XDRAW 1 AT X,Y
+
+				; XDRAW does an exclusive-or shape table
+				; draw, so it draws the spiral first, then
+				; undraws it on the second pass
+
 				; Both A and X are 0 at exit
 				; Z flag set on exit
 				; Y varies
 
 	beq	tiny_loop	; bra
 
-
-our_shape = $E2DF
+	; o/~ No way to stop o/~
 
 
+
+our_shape = $E2DF		; location in the Applesoft ROM
+				; that holds $11,$F0,$03,$20,$00
+				; which makes a nice line in shape table
+				; (it points into the code for the FRE()
+				;  BASIC routine but that's not important)
+