From 278dfb9c3f6386201bcd3c15db3f99ad9188d8dd Mon Sep 17 00:00:00 2001
From: Vince Weaver <vince@deater.net>
Date: Mon, 11 Jan 2021 12:50:14 -0500
Subject: [PATCH] rotoplasma: optimize some more

about 6fps

theoretical max might be around 10fps
---
 graphics/gr/rotozoom/plasma.s           | 35 ++++++++++++++++++++-----
 graphics/gr/rotozoom/rotoplasma.s       |  8 +++---
 graphics/gr/rotozoom/rotozoom_texture.s | 32 +++++++++-------------
 3 files changed, 45 insertions(+), 30 deletions(-)

diff --git a/graphics/gr/rotozoom/plasma.s b/graphics/gr/rotozoom/plasma.s
index 1ebe1181..cb332821 100644
--- a/graphics/gr/rotozoom/plasma.s
+++ b/graphics/gr/rotozoom/plasma.s
@@ -1,5 +1,7 @@
 
-lookup = $d00
+texture = $d00
+high_lookup = $e00
+low_lookup = $f00
 
 ;col = ( 8.0 + (sintable[xx&0xf])
 ;           + 8.0 + (sintable[yy&0xf])
@@ -17,7 +19,7 @@ create_xloop:
 	adc	sinetable,Y
 	lsr
 lookup_smc:
-	sta	lookup		; always starts at $d00
+	sta	texture		; always starts at $d00
 
 	inc	lookup_smc+1
 
@@ -39,15 +41,34 @@ cycle_colors:
 	; cycle colors
 
 	ldx	#0
-cycle_loop:
-	inc	lookup,X
+cycle_texture_loop:
+	inc	texture,X
 
-	lda	lookup,X	; slow here but faster than doing it
+	lda	texture,X	; slow here but faster than doing it
 	and	#$f		; in the draw routine
-	sta	lookup,X
+	sta	texture,X
 
 	inx
-	bne	cycle_loop
+	bne	cycle_texture_loop
+
+	; make lookup
+
+	ldx	#0
+cycle_lookup_loop:
+	lda	texture,X
+	lsr
+	tay
+color_lookup_smc:
+	lda	green_lookup,Y
+	pha
+	and	#$f0
+	sta	high_lookup,X
+	pla
+	and	#$0f
+	sta	low_lookup,X
+
+	inx
+	bne	cycle_lookup_loop
 
 	rts
 
diff --git a/graphics/gr/rotozoom/rotoplasma.s b/graphics/gr/rotozoom/rotoplasma.s
index 53789d58..be530dac 100644
--- a/graphics/gr/rotozoom/rotoplasma.s
+++ b/graphics/gr/rotozoom/rotoplasma.s
@@ -94,11 +94,11 @@ refresh_color:
 	tay
 
 	lda	colorlookup,Y
-	sta	colorlookup_smc+1
-	sta	colorlookup2_smc+1
+	sta	color_lookup_smc+1
+;	sta	colorlookup2_smc+1
 	lda	colorlookup+1,Y
-	sta	colorlookup_smc+2
-	sta	colorlookup2_smc+2
+	sta	color_lookup_smc+2
+;	sta	colorlookup2_smc+2
 
 at_far_end:
 
diff --git a/graphics/gr/rotozoom/rotozoom_texture.s b/graphics/gr/rotozoom/rotozoom_texture.s
index 505a7273..25ddea36 100644
--- a/graphics/gr/rotozoom/rotozoom_texture.s
+++ b/graphics/gr/rotozoom/rotozoom_texture.s
@@ -12,6 +12,9 @@
 
 ; $2E7CF = 190,415 = 5.25fps	first merging
 ; $2D8CF = 186,575 = 5.35fps	move mask to rotate not draw
+; $29CCF = 171,215 = 5.84fps	do color conversion outside of loop
+; $28DCF = 167,375 = 5.97fps	two lookup tables for hi/low
+; $26FCF = 159,695 = 6.26fps	remove carry set/clear for fixed point adds
 
 CAL	= $B0
 CAH	= $B1
@@ -221,16 +224,10 @@ rotozoom_xloop:
 	adc	CTEMP			; 3
 	tay				; 2
 
-	lda	lookup,Y		; 4
-;	and	#$f			; 2
-	lsr				; 2
-	tay				; 2
+	lda	low_lookup,Y		; 4
 
-colorlookup2_smc:
-	lda	green_lookup,Y		; 4
-	and	#$0f			; 2
 				;============
-				;	40
+				;	30
 rscrn_done:
 
 
@@ -270,7 +267,8 @@ rplot2_smc:
 
 	; xp=xp+ca;	fixed point 8.8
 
-	clc								; 2
+; always set?  also low importance LSB
+;	clc								; 2
 	lda	CAL							; 3
 	adc	XPL							; 3
 	sta	XPL							; 3
@@ -280,7 +278,8 @@ rplot2_smc:
 
 	; yp=yp-sa;	fixed point 8.8
 
-	sec								; 2
+; low importance LSB?
+;	sec								; 2
 	lda	YPL							; 3
 	sbc	SAL							; 3
 	sta	YPL							; 3
@@ -385,13 +384,8 @@ rotozoom_xloop2:
 	adc	CTEMP
 	tay
 
-	lda	lookup,Y
-;	and	#$f
-	lsr
-	tay
-colorlookup_smc:
-	lda	green_lookup,Y
-	and	#$f0
+	lda	high_lookup,Y
+;	and	#$f0
 
 ;=============================================
 
@@ -426,7 +420,7 @@ rplot22_smc:
 
 	; xp=xp+ca;	8.8 fixed point
 
-	clc								; 2
+;	clc								; 2
 	lda	CAL							; 3
 	adc	XPL							; 3
 	sta	XPL							; 3
@@ -436,7 +430,7 @@ rplot22_smc:
 
 	; yp=yp-sa;	8.8 fixed point
 
-	sec								; 2
+;	sec								; 2
 	lda	YPL							; 3
 	sbc	SAL							; 3
 	sta	YPL							; 3