# HG changeset patch
# User Mike Pavone <pavone@retrodev.com>
# Date 1378108938 25200
# Node ID e9b6fe443bf27e08b2de031e19d2185cc1bb6396
# Parent  b491df8bdbc0da2f85dcca99ffd7eff6e2c742cd
Fix per-column scrolling bug

diff -r b491df8bdbc0 -r e9b6fe443bf2 vdp.c
--- a/vdp.c	Mon Sep 02 00:20:56 2013 -0700
+++ b/vdp.c	Mon Sep 02 01:02:18 2013 -0700
@@ -619,7 +619,7 @@
 		vscroll <<= 1;
 		vscroll |= 1;
 	}
-	vscroll &= (context->vsram[(context->regs[REG_MODE_3] & BIT_VSCROLL ? column : 0) + vsram_off] + line);
+	vscroll &= (context->vsram[(context->regs[REG_MODE_3] & BIT_VSCROLL ? (column-2)&63 : 0) + vsram_off] + line);
 	context->v_offset = vscroll & v_offset_mask;
 	//printf("%s | line %d, vsram: %d, vscroll: %d, v_offset: %d\n",(vsram_off ? "B" : "A"), line, context->vsram[context->regs[REG_MODE_3] & 0x4 ? column : 0], vscroll, context->v_offset);
 	vscroll >>= vscroll_shift;