From 5cb27a552457ba234cd4983d0687b2bc7fde0e6d Mon Sep 17 00:00:00 2001
From: Vince Weaver <vince@deater.net>
Date: Fri, 3 Feb 2023 22:57:53 -0500
Subject: [PATCH] blue_flame: more optimization, still 5 bytes too big

---
 demos/lovebyte2023/1k/blue_flame.s       |  2 +
 demos/lovebyte2023/1k/letters_routines.s | 32 +++++----------
 demos/lovebyte2023/1k/sier.s             | 51 +++++-------------------
 demos/lovebyte2023/1k/static_column.s    | 20 ++++------
 demos/lovebyte2023/1k/zp.inc             |  3 +-
 5 files changed, 31 insertions(+), 77 deletions(-)

diff --git a/demos/lovebyte2023/1k/blue_flame.s b/demos/lovebyte2023/1k/blue_flame.s
index c60f2fcf..136c6050 100644
--- a/demos/lovebyte2023/1k/blue_flame.s
+++ b/demos/lovebyte2023/1k/blue_flame.s
@@ -15,6 +15,8 @@
 ; 1038 bytes (+18) -- re-arrange sound init so don't have to set Y to 0
 ; 1035 bytes (+15) -- combine memory zeroing functions
 ; 1033 bytes (+13) -- inline letters code
+; 1029 bytes (+9)  -- remove unecessary initialization in column code
+; 1025 bytes (+5)  -- optimize page flip
 
 .include "zp.inc"
 .include "hardware.inc"
diff --git a/demos/lovebyte2023/1k/letters_routines.s b/demos/lovebyte2023/1k/letters_routines.s
index ed75eb28..0fc62090 100644
--- a/demos/lovebyte2023/1k/letters_routines.s
+++ b/demos/lovebyte2023/1k/letters_routines.s
@@ -91,24 +91,6 @@ xdraw_offset_smc:
 
 	jmp	XDRAW0			; tail call
 
-.if 0
-	;=======================
-	; flip page
-	;=======================
-
-flip_page:
-	lda	HGR_PAGE
-	eor	#$60
-	sta	HGR_PAGE
-
-	clc
-	rol
-	rol
-	tax
-	lda	PAGE1,X
-
-	rts
-.endif
 
 .if 0
 
@@ -156,11 +138,6 @@ loop:
 
 .align $100
 
-rotate_pattern:
-	; offset by 3 to give original effect
-;	.byte 0,3,6
-	.byte 9, 9,6,3,0, 0,$FD,$FA,$F7, $F7,$FA,$FD, 0
-	.byte 0,3,6
 
 deater_offsets:
 	.byte 0		; D
@@ -171,6 +148,7 @@ deater_offsets:
 	.byte 30	; R
 	.byte $FF	; end
 
+
 ma2e_offsets:
 	.byte 8		; E
 	.byte 47	; 2
@@ -197,6 +175,11 @@ desire_ends:
 ma2e_ends:
 	.byte	 188,156,124,92
 
+rotate_pattern:
+	; offset by 3 to give original effect
+;	.byte 0,3,6
+	.byte 9, 9,6,3,0, 0,$FD,$FA,$F7, $F7,$FA,$FD, 0
+	.byte 0,3,6
 
 
 shape_table:
@@ -212,6 +195,9 @@ shape_table_s:	.byte	$27,$2c,$95,$2b, $36,$3f,$00		; 54
 shape_table_i:	.byte	$d2,$ed,$24,$e4, $2d,$00		; 61
 shape_table_hline:	.byte	$2b,$05,$00			; 67
 
+
+
+
 ;shape_table_vline:	.byte	$12,$24,$24,$00			; 67
 ;shape_table_o:	.byte	$23,$2c,$35,$36, $3e,$27,$04,$00	;
 ;shape_table_v:	.byte	$18,$30,$36,$35, $28,$24,$04,$00	;
diff --git a/demos/lovebyte2023/1k/sier.s b/demos/lovebyte2023/1k/sier.s
index e1e38ac6..1d9ec646 100644
--- a/demos/lovebyte2023/1k/sier.s
+++ b/demos/lovebyte2023/1k/sier.s
@@ -15,46 +15,7 @@
 
 sier_parallax:
 
-.if 0
-	;===================
-	; init screen
-
-; already done for us
-
-;	jsr	HGR			; clear PAGE1
-;	jsr	HGR2			; clear PAGE2
-
-	;===================
-        ; int tables
-
-        ldx     #191
-sinit_loop:
-        txa
-        pha
-        jsr     HPOSN
-        pla
-        tax
-        lda     GBASL
-        sta     hgr_lookup_l,X
-        lda     GBASH
-	and	#$1F				; 20 30    001X 40 50  010X
-        sta     hgr_lookup_h,X
-
-
-        dex
-        cpx     #$ff
-        bne     sinit_loop
-
-	ldx	#39
-div4_loop:
-	txa
-	asl
-	asl
-	sta	div4_lookup,X
-	dex
-	bpl	div4_loop
-
-.endif
+	; table init moved to main routine
 
 parallax_forever:
 
@@ -71,10 +32,18 @@ parallax_forever:
 	eor	#$60                    ; flip draw_page
 	sta	HGR_PAGE
 
+	;              asl  asl       rol      eor
+	; want: $40 -> $80  C=1 $00  c=0  $01   $00 (page1)
+	;       $20 -> $40  C=0 $80  c=1, $00   $01 (page2)
+
+	; what if      asl     asl    asl   rol
+	;	$40 -> $80 -> $00 -> $00 -> $00
+	;	$20 -> $40 -> $80 -> C=1  -> $01
+	asl
 	asl
 	asl
 	rol
-	eor	#$1
+
 	tax
 	lda     PAGE1,X			; flip show_page
 
diff --git a/demos/lovebyte2023/1k/static_column.s b/demos/lovebyte2023/1k/static_column.s
index 89ce78c4..430af8c0 100644
--- a/demos/lovebyte2023/1k/static_column.s
+++ b/demos/lovebyte2023/1k/static_column.s
@@ -1,11 +1,5 @@
 	; shimmery blue pattern
 
-INDEXL          = $F6
-INDEXH          = $F7
-
-;HGR2            = $F3D8         ; set hires page2 and clear $4000-$5fff
-;WAIT            = $FCA8         ; delay 1/2(26+27A+5A^2) us
-
 
 even_lookup=$f000
 odd_lookup=$f100
@@ -16,13 +10,13 @@ staggered:
 
 ;	tax					; init X to 0
 
-	ldx	#0
-	stx	INDEXL				; set INDEXL to 0
+; set earlier
+;	ldx	#0
+;	stx	INDEXL				; set INDEXL to 0
 
 	; pulse loop horizontal
 outer_loop:
-;	lda	#$40				; reset INDEXH to begin page2
-	lda	#$20				; reset INDEXH to begin page2
+	lda	#$20				; reset INDEXH to begin page1
 	sta	INDEXH
 
 inner_loop:
@@ -44,18 +38,20 @@ inner_loop:
 	and	#$7
 	tax
 
-;	lda	#$60				; see if done
 	lda	#$40				; see if done
 	cmp	INDEXH
 	bne	inner_loop
 
-;	lda	#100				; A is $60 here
+;	lda	#100				; A is $40 here
 	jsr	WAIT				; pause a bit
 
 	; A is 0 here
 
 	inx					; offset next FRAME
 
+	; if FRAMEH is 4 then done
+
 	lda	FRAMEH
 	cmp	#4
+
 	bne	outer_loop
diff --git a/demos/lovebyte2023/1k/zp.inc b/demos/lovebyte2023/1k/zp.inc
index 90634336..20234495 100644
--- a/demos/lovebyte2023/1k/zp.inc
+++ b/demos/lovebyte2023/1k/zp.inc
@@ -21,7 +21,8 @@ FRAME		= $80
 FRAMEH		= $81
 WHICH_TRACK	= $82
 SONG_COUNTDOWN	= $83
-
+INDEXL		= $84
+INDEXH		= $85
 
 OUR_ROT		= $A5