# HG changeset patch
# User Mike Pavone <pavone@retrodev.com>
# Date 1355011783 28800
# Node ID 30ae73f962671c7e64e9bb99560b033048bf3ed1
# Parent  3e924bb56560b2c32b22e903472c75adcdfa0950
Partially fix BG plane B

diff -r 3e924bb56560 -r 30ae73f96267 vdp.c
--- a/vdp.c	Sat Dec 08 16:02:17 2012 -0800
+++ b/vdp.c	Sat Dec 08 16:09:43 2012 -0800
@@ -129,9 +129,8 @@
 	//TODO: Implement me
 }
 
-void read_map_scroll(uint16_t column, uint32_t line, uint32_t scroll_reg, uint16_t hscroll_val, vdp_context * context)
+void read_map_scroll(uint16_t column, uint32_t line, uint16_t address, uint16_t hscroll_val, vdp_context * context)
 {
-	uint16_t address = (context->regs[scroll_reg] & 0x38) << 10;
 	uint16_t vscroll;
 	switch(context->regs[REG_SCROLL] & 0x30)
 	{
@@ -186,12 +185,12 @@
 
 void read_map_scroll_a(uint16_t column, uint32_t line, vdp_context * context)
 {
-	read_map_scroll(column, line, REG_SCROLL_A, context->hscroll_a, context);
+	read_map_scroll(column, line, (context->regs[REG_SCROLL_A] & 0x38) << 10, context->hscroll_a, context);
 }
 
 void read_map_scroll_b(uint16_t column, uint32_t line, vdp_context * context)
 {
-	read_map_scroll(column, line, REG_SCROLL_B, context->hscroll_b, context);
+	read_map_scroll(column, line, (context->regs[REG_SCROLL_B] & 0x7) << 13, context->hscroll_b, context);
 }
 
 void render_map(uint16_t col, uint8_t * tmp_buf, vdp_context * context)