# HG changeset patch
# User Michael Pavone <pavone@retrodev.com>
# Date 1489953260 25200
# Node ID aa1a8eb5bb2b43554ec2adb428f6254e5af47745
# Parent  6ad59a62e656b3f9828b1ce0d5b0d57874399b4e
Change handling of invalid scroll plane sizes. Fixes title and high score screens in The Incredible Hulk

diff -r 6ad59a62e656 -r aa1a8eb5bb2b vdp.c
--- a/vdp.c	Sun Mar 19 11:17:40 2017 -0700
+++ b/vdp.c	Sun Mar 19 12:54:20 2017 -0700
@@ -998,23 +998,8 @@
 		}
 		context->flags &= ~FLAG_WINDOW;
 	}
-	uint16_t vscroll;
-	switch(context->regs[REG_SCROLL] & 0x30)
-	{
-	case 0:
-		vscroll = 0xFF;
-		break;
-	case 0x10:
-		vscroll = 0x1FF;
-		break;
-	case 0x20:
-		//TODO: Verify this behavior
-		vscroll = 0;
-		break;
-	case 0x30:
-		vscroll = 0x3FF;
-		break;
-	}
+	//TODO: Verify behavior for 0x20 case
+	uint16_t vscroll = 0xFF | (context->regs[REG_SCROLL] & 0x30) << 4;
 	if (context->double_res) {
 		vscroll <<= 1;
 		vscroll |= 1;
@@ -1057,7 +1042,7 @@
 		break;
 	case 0x2:
 		//TODO: Verify this behavior
-		hscroll_mask = 0;
+		hscroll_mask = 0x5F;
 		v_mul = 0;
 		break;
 	case 0x3: