fix cell scroll drawing

[picodrive.git] / pico / draw.c

diff --git a/pico/draw.c b/pico/draw.c
index 6408f20..bb051b6 100644 (file)
--- a/pico/draw.c
+++ b/pico/draw.c
@@ -261,7 +261,11 @@ static void DrawStripVSRam(struct TileStrip *ts, int plane_sh, int cellskip)
   // Draw tiles across screen:\r
   tilex=(-ts->hscroll)>>3;\r
   dx=((ts->hscroll-1)&7)+1;\r
-  if(dx != 8) cell--; // have hscroll, start with negative cell\r
+  if (ts->hscroll & 0x0f) {\r
+    int adj = ((ts->hscroll ^ dx) >> 3) & 1;\r
+    cell -= adj + 1;\r
+    ts->cells -= adj;\r
+  }\r
   cell+=cellskip;\r
   tilex+=cellskip;\r
   dx+=cellskip<<3;\r