From 4bf391b1c863054b7818ca139adf799ed30911c6 Mon Sep 17 00:00:00 2001
From: Lior Halphon <LIJI32@gmail.com>
Date: Sat, 25 Feb 2017 23:30:31 +0200
Subject: [PATCH] =?UTF-8?q?SCX=20now=20effects=20Mode=203=E2=80=99s=20leng?=
=?UTF-8?q?th.=20Fixes=20hblank=5Fly=5Fscx=5Ftiming-GS?=
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---
Core/display.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/Core/display.c b/Core/display.c
index feb0babc..4e892ed7 100755
--- a/Core/display.c
+++ b/Core/display.c
@@ -346,6 +346,8 @@ static void update_display_state(GB_gameboy_t *gb, uint8_t cycles)
uint8_t atomic_increase = gb->cgb_double_speed? 2 : 4;
uint8_t stat_delay = gb->cgb_double_speed? 2 : (gb->cgb_mode? 0 : 4);
+ /* This is correct for DMG. Is it correct for the 3 CGB modes (DMG/single/double)?*/
+ uint8_t scx_delay = ((gb->effective_scx & 7) + atomic_increase - 1) & ~(atomic_increase - 1);
for (; cycles; cycles -= atomic_increase) {
gb->display_cycles += atomic_increase;
@@ -399,8 +401,10 @@ static void update_display_state(GB_gameboy_t *gb, uint8_t cycles)
else if (position_in_line == MODE2_LENGTH + stat_delay) {
gb->io_registers[GB_IO_STAT] &= ~3;
gb->io_registers[GB_IO_STAT] |= 3;
+ gb->effective_scx = gb->io_registers[GB_IO_SCX];
+ gb->previous_lcdc_x = - (gb->effective_scx & 0x7);
}
- else if (position_in_line == MODE2_LENGTH + MODE3_LENGTH + stat_delay) {
+ else if (position_in_line == MODE2_LENGTH + MODE3_LENGTH + stat_delay + scx_delay) {
gb->io_registers[GB_IO_STAT] &= ~3;
if (gb->hdma_on_hblank) {
gb->hdma_on = true;
@@ -566,9 +570,6 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
if (gb->effective_window_enabled && gb->effective_window_y == 0xFF) {
gb->effective_window_y = effective_ly;
}
-
- gb->effective_scx = gb->io_registers[GB_IO_SCX];
- gb->previous_lcdc_x = - (gb->effective_scx & 0x7);
return;
}