From 024d38ce3605a581328524ef33bac5159c083375 Mon Sep 17 00:00:00 2001
From: Vince Weaver <vince@deater.net>
Date: Sun, 26 Nov 2017 01:02:02 -0500
Subject: [PATCH] tfv: update with over_water optimization

---
 gr-sim/tfv_flying_6502.c |  37 +++++++++++++-----------
 tfv/OPTIMIZATION         |  13 +++++++++
 tfv/TODO                 |  16 +++--------
 tfv/tfv.dsk              | Bin 143360 -> 143360 bytes
 tfv/tfv_flying.s         |  50 ++++++++++++++++++++------------
 tfv/tfv_zp.inc           |  60 +++++++++++++++++++--------------------
 6 files changed, 100 insertions(+), 76 deletions(-)

diff --git a/gr-sim/tfv_flying_6502.c b/gr-sim/tfv_flying_6502.c
index d28cbfcf..dbf0a913 100644
--- a/gr-sim/tfv_flying_6502.c
+++ b/gr-sim/tfv_flying_6502.c
@@ -42,7 +42,7 @@
 #define DRAW_SPLASH	0x7a
 #define SPEED		0x7b
 #define SPLASH_COUNT	0x7c
-#define OVER_WATER	0x7d
+#define OVER_LAND	0x7d
 #define NUM1L		0x7E
 #define NUM1H		0x7F
 #define NUM2L		0x80
@@ -799,13 +799,14 @@ shift_output:
 
 #endif
 
-void draw_background_mode7(void) {
+
+
+static void draw_background_mode7(void) {
 
 
 	int map_color;
 
-	ram[OVER_WATER]=0;
-						cycles.mode7+=11;
+						cycles.mode7+=6;
 	if (ram[DRAW_SKY]) {
 
 		ram[DRAW_SKY]--;
@@ -828,6 +829,7 @@ void draw_background_mode7(void) {
 
 
 						cycles.mode7+=30;
+
 	/* FIXME: only do this if SPACEZ changes? */
 // mul1
 	fixed_mul(ram[SPACEZ_I],ram[SPACEZ_F],
@@ -841,10 +843,6 @@ void draw_background_mode7(void) {
 			ram[FACTOR_I],ram[FACTOR_F]);
 	}
 
-//	printf("spacez=%lf beta=%lf factor=%lf\n",
-//		fixed_to_double(ram[SPACEZ_I],ram[SPACEZ_F],),
-//		fixed_to_double(&BETA),
-//		fixed_to_double(ram[FACTOR_I],ram[FACTOR_F]));
 							cycles.mode7+=12;
 
 	for (ram[SCREEN_Y] = 8; ram[SCREEN_Y] < LOWRES_H; ram[SCREEN_Y]+=2) {
@@ -977,12 +975,12 @@ void draw_background_mode7(void) {
 			ram[COLOR]=map_color;
 			ram[COLOR]|=map_color<<4;
 
-			if ((ram[SCREEN_X]==20) && (ram[SCREEN_Y]==38)) {
-				if (map_color==COLOR_DARKBLUE) ram[OVER_WATER]=1;
-			}
+//			if ((ram[SCREEN_X]==20) && (ram[SCREEN_Y]==38)) {
+//				if (map_color==COLOR_DARKBLUE) ram[OVER_WATER]=1;
+//			}
 
 			hlin_double_continue(1);
-							cycles.mode7+=42;
+							cycles.mode7+=19;
 
 			// advance to the next position in space
 			fixed_add(ram[SPACEX_I],ram[SPACEX_F],
@@ -1043,7 +1041,6 @@ int flying(void) {
 	ram[DRAW_SPLASH]=0;
 	ram[SPEED]=0;
 	ram[SPLASH_COUNT]=0;
-	ram[OVER_WATER]=0;
 
 	ram[ANGLE]=1;		/* 1 so you can see island */
 
@@ -1140,7 +1137,6 @@ int flying(void) {
 
 				/* Land the ship */
 				for(loop=ram[SPACEZ_I];loop>0;loop--) {
-
 					draw_background_mode7();
 					cycles.put_sprite+=grsim_put_sprite(shadow_forward,CONST_SHIPX+3,31+ram[SPACEZ_I]);
 					cycles.put_sprite+=grsim_put_sprite(ship_forward,CONST_SHIPX,ram[SHIPY]);
@@ -1189,7 +1185,16 @@ int flying(void) {
 		}
 
 		draw_background_mode7();
-						cycles.flying+=6;
+
+		{	int landing_color,tx,ty;
+			tx=ram[CX_I];	ty=ram[CY_I];
+
+			landing_color=lookup_map(tx,ty);
+			if (landing_color==2) ram[OVER_LAND]=0;
+			else ram[OVER_LAND]=1;
+		}
+						cycles.flying+=31;
+
 		ram[DRAW_SPLASH]=0;
 						cycles.flying+=11;
 		if (ram[SPEED]>0) {
@@ -1198,7 +1203,7 @@ int flying(void) {
 				ram[SPLASH_COUNT]=1;
 			}
 
-			if ((ram[OVER_WATER]) && (ram[SPLASH_COUNT])) {
+			if ((!ram[OVER_LAND]) && (ram[SPLASH_COUNT])) {
 				ram[DRAW_SPLASH]=1;
 			}
 		}
diff --git a/tfv/OPTIMIZATION b/tfv/OPTIMIZATION
index 35aeb721..ba32c857 100644
--- a/tfv/OPTIMIZATION
+++ b/tfv/OPTIMIZATION
@@ -84,3 +84,16 @@ Don't draw sky every frame
 	Total =                  121,478
 	Frame Rate = 8.23 fps
 
+Move checking if over water out of critical section
+
+	Cycles: flying=              187
+	Cycles: getkey=               46
+	Cycles: page_flip=            26
+	Cycles: multiply=         24,935
+	Cycles: mode7=            54,374
+	Cycles: lookup_map=       24,712
+	Cycles: put_sprite=        2,561
+	=================================
+	Total =                  106,841
+	Frame Rate = 9.36 fps
+
diff --git a/tfv/TODO b/tfv/TODO
index fcc7b78e..23176148 100644
--- a/tfv/TODO
+++ b/tfv/TODO
@@ -1,18 +1,10 @@
 mode7 speed fixes:
-	+ Don't draw sky every frame, only if needed
-
 	+ faster multiply routine
-	+ If result is AABBCCDD we only need BBCC for fixed point
-		result
-	+ Pass NUM1H in A? no because used multiple places
-	+ inline hlin_setup? (save 12 cycles)
+		- If result is AABBCCDD we only need BBCC for fixed point
+			result
+		- Pass NUM1H in A? no because used multiple places
 
-	+ re-arrange variables to better take advantage of self-modifying code
-	+ only doing the spacez calculation if it has changed
-	+ update the constants to be constants
-	+ move the screen width constant to own set of varaibles
-		(instead of temp)
-	+ leave one of multiply results in accumulator at end?
+	+ inline hlin_setup? (save 12 cycles)
 
 	+  Skip key parsing if no key read
 
diff --git a/tfv/tfv.dsk b/tfv/tfv.dsk
index 5622ae6d71278f691edbcffe7ccee050ca473c42..c09d89fa09fc37861851533cc71dbd6cd85373cc 100644
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diff --git a/tfv/tfv_flying.s b/tfv/tfv_flying.s
index 30b192b2..b99cb9ba 100644
--- a/tfv/tfv_flying.s
+++ b/tfv/tfv_flying.s
@@ -42,7 +42,6 @@ flying_start:
 	sta	DRAW_SPLASH
 	sta	SPEED
 	sta	SPLASH_COUNT
-	sta	OVER_WATER
 
 	lda	#1
 	sta	ANGLE
@@ -339,6 +338,21 @@ speed_loop:
 draw_background:
 	jsr	draw_background_mode7					; 6
 
+check_over_water:
+	;	See if we are over water
+	lda	CX_I							; 3
+	sta	SPACEX_I						; 3
+	lda	CY_I							; 3
+	sta	SPACEY_I						; 3
+
+	jsr	lookup_map						; 6
+
+	sec								; 2
+	sbc	#COLOR_BOTH_DARKBLUE					; 2
+	sta	OVER_LAND						; 3
+								;===========
+								;	31
+
 	; Calculate whether to draw the splash
 
 	lda	#0			; set splash drawing to 0	; 2
@@ -358,8 +372,8 @@ draw_background:
 	sta	SPLASH_COUNT						; 3
 
 no_turning_splash:
-	lda	OVER_WATER	; no splash if over land		; 3
-	beq	no_splash						; 2nt/3
+	lda	OVER_LAND	; no splash if over land		; 3
+	bne	no_splash						; 2nt/3
 
 	lda	SPLASH_COUNT	; no splash if splash_count expired	; 3
 	beq	no_splash						; 2nt/3
@@ -533,9 +547,6 @@ draw_ship:
 
 draw_background_mode7:
 
-	lda	#0							; 2
-	sta	OVER_WATER						; 3
-
 	lda	DRAW_SKY						; 3
 	beq	no_draw_sky						; 2nt/3
 
@@ -580,6 +591,9 @@ sky_loop:				; draw line across screen
 no_draw_sky:
 
 	; FIXME: only do this if Z changes?
+	; 	only saves 200 cycles to do that with a lot of
+	; 	added complexity elsewhere
+
 	; fixed_mul(&space_z,&BETA,&factor);
 ;mul1
 	lda	SPACEZ_I						; 3
@@ -909,22 +923,22 @@ screenx_loop:
 	inc	GBASL			; point to next pixel		; 5
 
 	; Check if over water
-	cmp	#$22			; see if dark blue		; 2
-	bne	not_watery						; 2nt/3
+;	cmp	#$22			; see if dark blue		; 2
+;	bne	not_watery						; 2nt/3
 
-	lda	SCREEN_Y	; only check pixel in middle of screen	; 3
-	cmp	#38							; 2
-	bne	not_watery						; 2nt/3
+;	lda	SCREEN_Y	; only check pixel in middle of screen	; 3
+;	cmp	#38							; 2
+;	bne	not_watery						; 2nt/3
 
-	lda	SCREEN_X	; only check pixel in middle of screen	; 3
-	cmp	#20							; 2
-	bne	not_watery						; 2nt/3
+;	lda	SCREEN_X	; only check pixel in middle of screen	; 3
+;	cmp	#20							; 2
+;	bne	not_watery						; 2nt/3
 
-	lda	#$1		; set over water			; 2
-	sta	OVER_WATER						; 3
+;	lda	#$1		; set over water			; 2
+;	sta	OVER_WATER						; 3
 								;============
-								;	 42
-not_watery:
+								;	 19
+;not_watery:
 	; advance to the next position in space
 
 	clc			; fixed_add(&space_x,&dx,&space_x);	; 2
diff --git a/tfv/tfv_zp.inc b/tfv/tfv_zp.inc
index 71f9ea62..e264a793 100644
--- a/tfv/tfv_zp.inc
+++ b/tfv/tfv_zp.inc
@@ -54,36 +54,36 @@ OUTH		EQU	$FF
 
 ;; Flying Routine Only
 
-TURNING         EQU     $60
-SCREEN_X        EQU     $61
-SCREEN_Y        EQU     $62
-ANGLE           EQU     $63
-HORIZ_SCALE_I   EQU     $64
-HORIZ_SCALE_F   EQU     $65
-FACTOR_I        EQU     $66
-FACTOR_F        EQU     $67
-DX_I            EQU     $68
-DX_F            EQU     $69
-SPACEX_I        EQU     $6A
-SPACEX_F        EQU     $6B
-CX_I            EQU     $6C
-CX_F            EQU     $6D
-DY_I            EQU     $6E
-DY_F            EQU     $6F
-SPACEY_I        EQU     $70
-SPACEY_F        EQU     $71
-CY_I            EQU     $72
-CY_F            EQU     $73
-TEMP_I          EQU     $74
-TEMP_F          EQU     $75
-DISTANCE_I      EQU     $76
-DISTANCE_F      EQU     $77
-SPACEZ_I        EQU     $78
-SPACEZ_F        EQU     $79
-DRAW_SPLASH     EQU     $7A
-SPEED           EQU     $7B
-SPLASH_COUNT    EQU     $7C
-OVER_WATER      EQU     $7D
+TURNING         EQU	$60
+SCREEN_X        EQU	$61
+SCREEN_Y        EQU	$62
+ANGLE           EQU	$63
+HORIZ_SCALE_I   EQU	$64
+HORIZ_SCALE_F   EQU	$65
+FACTOR_I        EQU	$66
+FACTOR_F        EQU	$67
+DX_I            EQU	$68
+DX_F            EQU	$69
+SPACEX_I        EQU	$6A
+SPACEX_F        EQU	$6B
+CX_I            EQU	$6C
+CX_F            EQU	$6D
+DY_I            EQU	$6E
+DY_F            EQU	$6F
+SPACEY_I        EQU	$70
+SPACEY_F        EQU	$71
+CY_I            EQU	$72
+CY_F            EQU	$73
+TEMP_I          EQU	$74
+TEMP_F          EQU	$75
+DISTANCE_I      EQU	$76
+DISTANCE_F      EQU	$77
+SPACEZ_I        EQU	$78
+SPACEZ_F        EQU	$79
+DRAW_SPLASH     EQU	$7A
+SPEED           EQU	$7B
+SPLASH_COUNT    EQU	$7C
+OVER_LAND	EQU	$7D
 NUM1L		EQU	$7E
 NUM1H		EQU	$7F
 NUM2L		EQU	$80