xmas2018: make scroller use lz4 compression instead of RLE

saves 300 bytes or so

mode7/scroller.c

@@ -1,6 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
 
 static unsigned char font[256][9]={
 	{0,0,0,0,0,0,0,0,0},	// 0
@@ -662,5 +664,17 @@ int main(int argc, char **argv) {
 	printf("; Compressed size = %d bytes\n",new_size);
 
 
+	int fd;
+
+	fd=open("scroll.raw",O_CREAT|O_WRONLY,0666);
+	if (fd<0) {
+		fprintf(stderr,"Error opening\n");
+		exit(1);
+	}
+	for(y=0;y<4;y++) {
+		write(fd,&row[y],256);
+	}
+	close(fd);
+
 	return 0;
 }

xmas_2018/Makefile

@@ -27,7 +27,7 @@ xmas2018.o:	xmas2018.s \
 	vapor_lock.s delay_a.s wait_keypress.s \
 	play_music.s mockingboard.s rts.s \
 	wreath.s wreath.img.lz4 sprites.inc \
-	ball.s ball.img.lz4 greets.inc gr_scroll.s \
+	ball.s ball.img.lz4 greets.raw.lz4 gr_scroll.s \
 	merry.s merry.img.lz4
 	ca65 -o xmas2018.o xmas2018.s -l xmas2018.lst
 

xmas_2018/README

@@ -4,11 +4,15 @@ Memory Map:
 	01	Stack
 	02-03	Reserved
 	04-07	GR PAGE0
-	08-0b	GR PAGE1
+	08-0b	GR PAGE1 (scroll text)
 	0c-1f	CODE	(5k)
 	20-3f	HGR PAGE0 (wreath)
 	40-5f	HGR PAGE1 (ball)
 	60-7f	(merry)
 	80-9f	(music)
-	a0-bf	(staging)
+	a0-bf	(music)
 	c0-ff	RESERVED/ROM
+
+SIZE:
+	3903	-- 12/18
+	3647	-- use LZ4 encryption on scroll text

xmas_2018/ball.s

@@ -31,13 +31,25 @@ ball:
 	;=============================
 	; decompress scroll image to $800
 
-	lda	#>a2_scroll
+	lda     #<greets
-	sta	INH
+	sta	LZ4_SRC
-	lda	#<a2_scroll
+	lda	#>greets
-	sta	INL
+	sta	LZ4_SRC+1
 
-	jsr	decompress_scroll
+	lda	#<(greets_end-8)	; skip checksum at end
+	sta	LZ4_END
+	lda	#>(greets_end-8)	; skip checksum at end
+	sta	LZ4_END+1
 
+	lda	#<$800
+	sta	LZ4_DST
+	lda	#>$800
+	sta	LZ4_DST+1
+
+	jsr	lz4_decode
+
+	lda	#237
+	sta	SCROLL_LENGTH
 
 	;==============================
 	; setup graphics for vapor lock
@@ -231,4 +243,6 @@ ball_done:
 
 
 .include "gr_scroll.s"
-.include "greets.inc"
+greets:
+.incbin "greets.raw.lz4",11
+greets_end:

xmas_2018/gr_scroll.s

@@ -63,83 +63,3 @@ no_wrap:
 done_wrap:
 	rts							; 6
 
-	;=======================
-	; decompress scroll
-	;=======================
-decompress_scroll:
-	ldy	#0
-	jsr	scroll_load_and_increment
-	sta	SCROLL_LENGTH
-
-	lda	#<scroll_row1
-	sta	OUTL
-	lda	#>scroll_row1
-	sta	OUTH
-
-decompress_scroll_loop:
-	jsr	scroll_load_and_increment	; load compressed value
-
-	cmp	#$A1			; EOF marker
-	beq	done_decompress_scroll	; if EOF, exit
-
-	pha				; save
-
-	and	#$f0			; mask
-	cmp	#$a0			; see if special AX
-	beq	decompress_scroll_special
-
-	pla				; note, PLA sets flags!
-
-	ldx	#$1			; only want to print 1
-	bne	decompress_scroll_run
-
-decompress_scroll_special:
-	pla
-
-	and	#$0f			; check if was A0
-
-	bne	decompress_scroll_color	; if A0 need to read run, color
-
-decompress_scroll_large:
-	jsr	scroll_load_and_increment	; get run length
-
-decompress_scroll_color:
-	tax				; put runlen into X
-	jsr	scroll_load_and_increment	; get color
-
-decompress_scroll_run:
-	sta	(OUTL),Y
-	pha
-
-	clc				; increment 16-bit pointer
-	lda	OUTL
-	adc	#$1
-	sta	OUTL
-	lda	OUTH
-	adc	#$0
-	sta	OUTH
-
-	pla
-
-	dex				; repeat for X times
-	bne	decompress_scroll_run
-
-	beq	decompress_scroll_loop	; get next run
-
-done_decompress_scroll:
-	rts
-
-
-scroll_load_and_increment:
-	lda	(INL),Y			; load and increment 16-bit pointer
-	pha
-	clc
-	lda	INL
-	adc	#$1
-	sta	INL
-	lda	INH
-	adc	#$0
-	sta	INH
-	pla
-	rts
-