From 4f7a269ba5d053bb824b5ffa0978799331a5f2d8 Mon Sep 17 00:00:00 2001
From: Asura <69095614+asuramaru@users.noreply.github.com>
Date: Mon, 2 Nov 2020 03:46:17 +0900
Subject: [PATCH] sfc: Report auto joypad polling in the HVBJOY register.

This corrects the reporting bit of HVBJOY to be set during the auto joypad
polling sequence.

This change will fix *SpellCraft - Aspects of Valor*. SpellCraft works by
polling JOY1 nonstop once menus are entered on every scanline, so with incorrect
HVBJOY bit 0 reporting, the game was thinking it was safe to read JOY1 during
the auto joypad polling sequence, so partially shifted in results were being
read back as valid. With this patch, you'll find that the game stops polling
between V:225 H:130 and V:228 H:256, which is the auto polling time range.
Before, it was polling during that time. As a result of this fix, the password
menu can be accessed safely without it closing immediately.

Fixes #86.
---
 bsnes/sfc/cpu/io.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bsnes/sfc/cpu/io.cpp b/bsnes/sfc/cpu/io.cpp
index dcb56418..5e90b587 100644
--- a/bsnes/sfc/cpu/io.cpp
+++ b/bsnes/sfc/cpu/io.cpp
@@ -38,7 +38,7 @@ auto CPU::readCPU(uint addr, uint8 data) -> uint8 {
 
   case 0x4212:  //HVBJOY
     data &= 0x3e;
-    data |= (status.autoJoypadActive) << 0;
+    data |= io.autoJoypadPoll && status.autoJoypadCounter < 33;
     data |= (hcounter() <= 2 || hcounter() >= 1096) << 6;  //hblank
     data |= (vcounter() >= ppu.vdisp()) << 7;              //vblank
     return data;