From 78b904dba3a9c433ab4fa3d6389569d3a1f58b7b Mon Sep 17 00:00:00 2001
From: alpine9000 <alex.g.brown@gmail.com>
Date: Sun, 27 Mar 2016 13:09:57 +1100
Subject: [PATCH] Some small optimisations

---
 024.simple_text/Makefile      |  2 +-
 024.simple_text/blit.s        |  9 ++--
 024.simple_text/blittext.s    | 89 +++++++++++++++++------------------
 024.simple_text/simple_text.s |  9 ++--
 4 files changed, 56 insertions(+), 53 deletions(-)

diff --git a/024.simple_text/Makefile b/024.simple_text/Makefile
index 0eb5802..59a9d64 100644
--- a/024.simple_text/Makefile
+++ b/024.simple_text/Makefile
@@ -11,7 +11,7 @@ IMAGES=font.png
 IMAGEDATA=$(addprefix out/, $(IMAGES:.png=.bin))
 VASM_EXTRA_ARGS=
 
-SYMBOL_INFO=-M
+#SYMBOL_INFO=-M
 LINK_COMMANDLINE=vlink -T link.script.x -brawbin1 $< $(OBJS) $(SYMBOL_INFO) -o out/main.bin
 
 include ../shared/base.mk
diff --git a/024.simple_text/blit.s b/024.simple_text/blit.s
index 0bebadd..9211826 100644
--- a/024.simple_text/blit.s
+++ b/024.simple_text/blit.s
@@ -5,12 +5,14 @@
 BLIT_LF_MINTERM		equ $ff
 
 BlitFillColor:
+	;; kills a0,d2,d3,d5,d5
 	;; a0 - bitplane
 	;; d0 - color#
 	;; d1 - height
 	;; d2 - ypos
 
-	movem.l	d0-a6,-(sp)
+	;; 	movem.l	d0-d5/a0,-(sp)
+	;; 	movem.l	a0,-(sp)
 	mulu.w	#SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH,d2
 	add.l	d2,a0
 	move.b	#0,d3				; bitplane #
@@ -37,6 +39,7 @@ BlitFillColor:
 	add.w	#SCREEN_WIDTH_BYTES,a0
 	cmp.b	#SCREEN_BIT_DEPTH,d3 		; all planes for a single line done ?	
 	bne	.loop				; no ? do the next plane
-	jsr 	WaitBlitter
-	movem.l (sp)+,d0-a6
+	;; 	jsr	WaitBlitter	
+	;; movem.l (sp)+,d0-d5/a0
+	;; movem.l	(sp)+,a0
 	rts
diff --git a/024.simple_text/blittext.s b/024.simple_text/blittext.s
index 6de042b..b7134c1 100644
--- a/024.simple_text/blittext.s
+++ b/024.simple_text/blittext.s
@@ -12,32 +12,35 @@ DrawText8:
 	;; a1 - text
 	;; d0 - xpos
 	;; d1 - ypos	
-	movem.l	d0/d2/a1,-(sp)
+	movem.l	d0-d5/a0-a2,-(sp)
+	jsr	WaitBlitter	
 	;; blitter config that is shared for every character
-	move.w 	#SCREEN_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTAMOD(a6)	;A modulo
-	move.w 	#SCREEN_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTBMOD(a6)	;B modulo	
-	move.w 	#SCREEN_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTCMOD(a6)	;C modulo
-	move.w 	#SCREEN_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTDMOD(a6)	;D modulo
-
+	move.w 	#SCREEN_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTAMOD(a6)	; A modulo
+	move.w 	#SCREEN_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTBMOD(a6)	; B modulo	
+	move.w 	#SCREEN_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTCMOD(a6)	; C modulo
+	move.w 	#SCREEN_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTDMOD(a6)	; D modulo
+        mulu.w	#SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH,d1			; ypos bytes
+	move.l	a1,a5
 .loop:
-	move.b	(a1)+,d2	; get next character
+	clr.l	d2
+	move.b	(a5)+,d2	; get next character
 	cmp.b	#0,d2		; 0 terminates the string
 	beq	.done
-	jsr	DrawChar8	; draw it
+	bsr	DrawChar8	; draw it
 	add.w	#FONT_WIDTH,d0	; increment the x position
 	bra	.loop
 .done:
-	movem.l	(sp)+,d0/d2/a1
+	movem.l	(sp)+,d0-d5/a0-a2
 	rts
 
 DrawChar8:
+	;; kills d2,d3,d4,d5,a1,a2
 	;; d0 - xpos
-	;; d1 - ypos
+	;; d1 - ypos bytes
 	;; d2 - char
 	;; a0 - bitplane
-	movem.l	d0-d5/a0-a2,-(sp)
-	move.w	#'!',d4 	; fontmap offset
-	sub.w	d4,d2		; index = char - '!'
+	movem.l	a0,-(sp)	
+	sub.w	#'!',d2		; index = char - '!'
 	move.w	d2,d5
 	lsr.w	#5,d5		; fontmap y offset
 	
@@ -46,7 +49,7 @@ DrawChar8:
 	sub.w	d4,d2		;
 	
 	add.w	#1,d5		; while we have a weird font image, '!' starts on second line
-	lea	font,a1
+	lea	font(pc),a1
 	lea	fontMask,a2
 	mulu.w	#SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT,d5
 	add.w	d5,a2
@@ -55,41 +58,37 @@ DrawChar8:
 	btst	#0,d2		; blitter does words only, so we need to know if its an odd or even character
 	beq	.even		; then shift it into position with the blitter shift
 .odd:
-	move.b	#1,d3
+	moveq	#1,d3
 	bra	.c1
 .even:	
-	move.b	#0,d3
+	moveq	#0,d3
 .c1
 
 	add.w	d2,a1
 	add.w	d2,a2
-	jsr	BlitChar8
-	movem.l	(sp)+,d0-d5/a0-a2
+	bsr	BlitChar8
+	movem.l	(sp)+,a0
 	rts
-
+	
 BlitChar8:
-	;; kills a0,d0,d3
+	;; kills a0,d2,d4
 	;; d0 - xpos
-	;; d1 - ypos
+	;; d1 - ypos bytes
 	;; d3 - odd character = 1, even character = 0
 	;; a0 - display
 	;; a1 - object
 	;; a2 - mask	
 
+ 	move.l	d0,d4	; d4 = XPOS
+ 	move.l	d0,d2	
+	lsr.w	#3,d4	; d4 = XPOS_BYTES
+	
 	jsr	WaitBlitter
 	
-	;; d0 = XPOS
-	;; d1 = YPOS
-	;; d3 = odd character
-	;; d4 = XPOS_BYTES
-
- 	move.l	d0,d4	; d4 = XPOS
-	lsr.w	#3,d4	; d4 = XPOS_BYTES
-
-	cmp.b	#1,d3
-	bne	.evenChar
+	btst	#0,d3
+	beq	.evenChar
 .oddChar
-	sub.w	#8,d0
+	sub.w	#8,d2
 	move.w	#$00FF,BLTAFWM(a6)	; no mask for first word
 	move.w	#$0000,BLTALWM(a6) 	; mask out last word
 	subq	#1,a0	
@@ -99,26 +98,24 @@ BlitChar8:
 	move.w	#$0000,BLTALWM(a6) 	; mask out last word
 .continue:
 
-	;; this shift will give us the bits to shift (bits 0-3) in bits (12-15) of d0
-	lsl.w	#8,d0	; BLIT_SOURCE_SHIFT<<BLIT_ASHIFTSHIFT
-	lsl.w	#4,d0 	; BLIT_SOURCE_SHIFT<<BLIT_ASHIFTSHIFT
+	;; this shift will give us the bits to shift (bits 0-3) in bits (12-15) of d2
 
-	move.w	d0,BLTCON1(A6)
-	ori.w   #BLIT_SRCA|BLIT_SRCB|BLIT_SRCC|BLIT_DEST|BLIT_LF_MINTERM,d0
-	move.w	d0,BLTCON0(A6)
+	lsl.w	#8,d2	; BLIT_SOURCE_SHIFT<<BLIT_ASHIFTSHIFT
+	lsl.w	#4,d2 	; BLIT_SOURCE_SHIFT<<BLIT_ASHIFTSHIFT
+	
+	move.w	d2,BLTCON1(A6)
+	ori.w   #BLIT_SRCA|BLIT_SRCB|BLIT_SRCC|BLIT_DEST|BLIT_LF_MINTERM,d2
+	move.w	d2,BLTCON0(A6)
 
 	move.l 	a2,BLTAPTH(a6)	; mask bitplane
 	move.l 	a1,BLTBPTH(a6)	; bob bitplane
 
-	move.w	#SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH,d3	; d3 = SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH
+	move.l 	a0,d2					; d2 = #bitplanes
+	add.l 	d4,d2					; d2 = #bitplanes+XPOS_BYTES
+	add.l	d1,d2					; d2 = #bitplanes+XPOS_BYTES+(YPOS*SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH)
 
-	mulu.w	d1,d3					; d3 = YPOS*SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH
-	move.l 	a0,d0					; d0 = #bitplanes
-	add.l 	d4,d0					; d0 = #bitplanes+XPOS_BYTES
-	add.l	d3,d0					; d0 = #bitplanes+XPOS_BYTES+(YPOS*SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH)
-
-	move.l 	d0,BLTCPTH(a6) ;background top left corner
-	move.l 	d0,BLTDPTH(a6) ;destination top left corner
+	move.l 	d2,BLTCPTH(a6) ;background top left corner
+	move.l 	d2,BLTDPTH(a6) ;destination top left corner
 
 	move.w 	#(FONT_HEIGHT*SCREEN_BIT_DEPTH)<<6|(BLIT_WIDTH_WORDS),BLTSIZE(a6)	;rectangle size, starts blit
 	rts
diff --git a/024.simple_text/simple_text.s b/024.simple_text/simple_text.s
index d290e08..3d8198e 100644
--- a/024.simple_text/simple_text.s
+++ b/024.simple_text/simple_text.s
@@ -33,12 +33,14 @@ Entry:
 	move.w	#SCREEN_HEIGHT,d1 ; height
 	move.w	#0,d2		  ; ypos
 	jsr	BlitFillColor
+
 	move.l	offscreen,a0
 	move.l	#4,d0		  ; color#
 	move.w	#SCREEN_HEIGHT,d1 ; height
 	move.w	#0,d2		  ; ypos	
-	jsr	BlitFillColor	
-
+	jsr	BlitFillColor
+	
+	jsr     WaitBlitter	
 	jsr	Init		  ; enable the playfield		
 
 MainLoop:		
@@ -50,7 +52,8 @@ MainLoop:
 	move.w	#FONT_HEIGHT,d1	  ; height
 	move.l	ypos,d2		  ; ypos	
 	jsr	BlitFillColor
-
+	
+	move.l	offscreen,a0	
 	move.l	ypos2,d2	
 	jsr	BlitFillColor