From: kub <derkub@gmail.com>
Date: Sat, 18 Feb 2023 17:19:05 +0000 (+0000)
Subject: sms vdp, fix TMS modes, tile count off by one
X-Git-Tag: v2.00~253
X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ecf8764253b478fc35729c24e3b6a2d31294bb33;p=picodrive.git

sms vdp, fix TMS modes, tile count off by one
---

diff --git a/pico/mode4.c b/pico/mode4.c
index 0b49395a..9cdf1c94 100644
--- a/pico/mode4.c
+++ b/pico/mode4.c
@@ -529,7 +529,7 @@ static void DrawSpritesTMS(void)
 static void DrawStripM1(const u8 *nametab, const u8 *pattab, int cells_dx, int tilex_ty)
 {
   // Draw tiles across screen:
-  for (; cells_dx > 0; cells_dx += 6, tilex_ty++, cells_dx -= 0x10000)
+  for (; cells_dx >= 0; cells_dx += 6, tilex_ty++, cells_dx -= 0x10000)
   {
     unsigned int pack, pal;
     unsigned code;
@@ -560,7 +560,7 @@ static void DrawDisplayM1(int scanline)
   pattab  += (scanline & 0x7);
 
   tilex = cellskip & 0x1f;
-  cells = maxcells - cellskip;
+  cells = maxcells - cellskip - 1;
   dx = 8 + (cellskip << 3) + line_offset;
 
   // tiles
@@ -576,7 +576,7 @@ static void DrawDisplayM1(int scanline)
 static void DrawStripM2(const u8 *nametab, const u8 *pattab, int cells_dx, int tilex_ty)
 {
   // Draw tiles across screen:
-  for (; cells_dx > 0; cells_dx += 8, tilex_ty++, cells_dx -= 0x10000)
+  for (; cells_dx >= 0; cells_dx += 8, tilex_ty++, cells_dx -= 0x10000)
   {
     unsigned int pal;
     unsigned code;
@@ -606,7 +606,7 @@ static void DrawDisplayM2(int scanline)
   pattab  += (scanline>>2) & 0x7;
 
   tilex = cellskip & 0x1f;
-  cells = maxcells - cellskip;
+  cells = maxcells - cellskip - 1;
   dx = (cellskip << 3) + line_offset;
 
   // tiles
@@ -626,7 +626,7 @@ static void DrawDisplayM2(int scanline)
 static void DrawStripM3(const u8 *nametab, const u8 *coltab, const u8 *pattab, int cells_dx, int tilex_ty)
 {
   // Draw tiles across screen:
-  for (; cells_dx > 0; cells_dx += 8, tilex_ty++, cells_dx -= 0x10000)
+  for (; cells_dx >= 0; cells_dx += 8, tilex_ty++, cells_dx -= 0x10000)
   {
     unsigned int pack, pal;
     unsigned code;
@@ -657,7 +657,7 @@ static void DrawDisplayM3(int scanline)
   pattab  += ((scanline>>6) <<11) + (scanline & 0x7);
 
   tilex = cellskip & 0x1f;
-  cells = maxcells - cellskip;
+  cells = maxcells - cellskip - 1;
   dx = (cellskip << 3) + line_offset;
 
   // tiles
@@ -677,7 +677,7 @@ static void DrawDisplayM3(int scanline)
 static void DrawStripM0(const u8 *nametab, const u8 *coltab, const u8 *pattab, int cells_dx, int tilex_ty)
 {
   // Draw tiles across screen:
-  for (; cells_dx > 0; cells_dx += 8, tilex_ty++, cells_dx -= 0x10000)
+  for (; cells_dx >= 0; cells_dx += 8, tilex_ty++, cells_dx -= 0x10000)
   {
     unsigned int pack, pal;
     unsigned code;
@@ -707,7 +707,7 @@ static void DrawDisplayM0(int scanline)
   pattab  += (scanline & 0x7);
 
   tilex = cellskip & 0x1f;
-  cells = maxcells - cellskip;
+  cells = maxcells - cellskip - 1;
   dx = (cellskip << 3) + line_offset;
 
   // tiles