From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sat, 13 Jan 2024 22:58:55 +0000 (+0200)
Subject: fixed nametab.B invalid address, and spr_submit with 0 sprites
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=commitdiff_plain;h=9e5bd0a52f0428e1a11df30714357d0fc95b3975;p=mdlife

fixed nametab.B invalid address, and spr_submit with 0 sprites
---

diff --git a/Makefile b/Makefile
index 6c173f8..d44e573 100644
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,7 @@ bin = $(name).bin
 
 warn = -pedantic -Wall
 dbg = -g
-opt = -O3
+#opt = -O3
 def = -D__NO_CTYPE
 inc = -I. -Isrc -Isrc/libc
 
@@ -91,6 +91,10 @@ install: $(bin)
 	[ -f /media/usbmass/MEGA/MEGA.RBF ] || cp $(bin) /media/usbmass/MEGA/MEGA.BIN
 	umount /media/usbmass
 
+.PHONY: debug
+debug: $(bin)
+	$(TC)gdb $(elf)
+
 # ---- tools ----
 PNGDUMP = tools/pngdump/pngdump
 
diff --git a/src/hwregs.h b/src/hwregs.h
index 4455811..2ab7591 100644
--- a/src/hwregs.h
+++ b/src/hwregs.h
@@ -116,7 +116,7 @@
 
 #define VDP_NA_ADDR(x)	(((x) >> 10) & 0x38)
 #define VDP_NW_ADDR(x)	(((x) >> 10) & 0x3e)
-#define VDP_NB_ADDR(x)	((x) >> 13)
+#define VDP_NB_ADDR(x)	(((x) >> 13) & 7)
 #define VDP_SPRTAB_ADDR(x)	((x) >> 9)
 #define VDP_HSTAB_ADDR(x)	((x) >> 10)
 
diff --git a/src/main.c b/src/main.c
index 29fb6d5..9478ee8 100644
--- a/src/main.c
+++ b/src/main.c
@@ -30,7 +30,7 @@ int main(void)
 	parts[0].update = dna_update;
 	parts[1].start = simba_start;
 	parts[1].update = simba_update;
-	part = parts + 1;
+	part = parts;
 
 	part->start();
 
diff --git a/src/part_simba.c b/src/part_simba.c
index 622bbbf..7c2611d 100644
--- a/src/part_simba.c
+++ b/src/part_simba.c
@@ -27,7 +27,7 @@ void simba_start(void)
 
 	/* setup tilemaps */
 	src = simbabg_tmap;
-	vdp_setup_addr(VDP_VRAM, 0xd000);	/* nametable B */
+	vdp_setup_addr(VDP_VRAM, 0xe000);	/* nametable B */
 	while(src < simbabg_tmap_end) {
 		VDP_DATA = VDP_TILENAME(*src++, 2, 0);
 	}
diff --git a/src/sprite.S b/src/sprite.S
index 158aaac..d258d62 100644
--- a/src/sprite.S
+++ b/src/sprite.S
@@ -8,11 +8,16 @@
 
 	.globl spr_submit
 spr_submit:
-	move.l spr_count, %d0
-	lsl.l #2, %d0			| 4 words per sprite
+	move.w spr_count, %d0
+	tst.w %d0
+	bne.s 0f
+	| if spr_count is zero, upload a single null sprite
+	addq.w #1, %d0
+0:	ext.l %d0
+	lsl.w #2, %d0			| 4 words per sprite
 	move.l %d0, -(%sp)
 	pea spr_shadow
-	pea 0xe000.w			| we placed the spirte table at e000
+	pea 0xd000.w			| we placed the spirte table at d000
 	jsr dma_systovram
 	addq.l #8, %sp
 	addq.l #4, %sp
diff --git a/src/sprite.c b/src/sprite.c
index 63305f3..9a6c6e7 100644
--- a/src/sprite.c
+++ b/src/sprite.c
@@ -3,7 +3,7 @@
 #include "vdp.h"
 
 struct hwsprite spr_shadow[MAX_HWSPRITES];
-int spr_count;
+short spr_count;
 
 void spr_begin(void)
 {
@@ -13,7 +13,7 @@ void spr_begin(void)
 
 void spr_add(int x, int y, unsigned int tile, int sprsz)
 {
-	int id;
+	short id;
 	struct hwsprite *spr;
 
 	if(spr_count >= MAX_HWSPRITES) {
diff --git a/src/sprite.h b/src/sprite.h
index 17050e9..7b90506 100644
--- a/src/sprite.h
+++ b/src/sprite.h
@@ -15,7 +15,7 @@ struct hwsprite {
 
 #define MAX_HWSPRITES	64
 extern struct hwsprite spr_shadow[MAX_HWSPRITES];
-extern int spr_count;
+extern short spr_count;
 
 void spr_begin(void);
 void spr_add(int x, int y, unsigned int tile, int sprsz);
diff --git a/src/vdp.S b/src/vdp.S
index 990a3ef..c1cf6a2 100644
--- a/src/vdp.S
+++ b/src/vdp.S
@@ -70,8 +70,8 @@ def_reg_tab:
 	.byte VDP_REG_MODE2, VDP_M2_INIT + VDP_M2_DISP	| 1: mode 2
 	.byte VDP_REG_NAMEA, VDP_NA_ADDR(0xc000)	| 2: scroll A nametable addr.
 	.byte VDP_REG_NAMEW, 0				| 3: window nametable addr.
-	.byte VDP_REG_NAMEB, VDP_NB_ADDR(0xd000)	| 4: scroll B nametable addr.
-	.byte VDP_REG_SPR, VDP_SPRTAB_ADDR(0xe000)	| 5: sprite table addr.
+	.byte VDP_REG_NAMEB, VDP_NB_ADDR(0xe000)	| 4: scroll B nametable addr.
+	.byte VDP_REG_SPR, VDP_SPRTAB_ADDR(0xd000)	| 5: sprite table addr.
 	.byte VDP_REG_BGCOL, 0				| 7: bg color
 	.byte VDP_REG_HINTR, 0				| 10: horiz. interrupt interval
 	.byte VDP_REG_MODE3, 0				| 11: mode 3