mirror/bsnes
1
0
Fork 0
mirror of https://github.com/bsnes-emu/bsnes.git synced 2025-09-02 01:32:56 +02:00
Code Issues Projects Releases Wiki Activity

Improve various edge cases of window emulation, improve the emulation of the last quirk

Browse Source
This commit is contained in:
Lior Halphon
2024-07-25 22:32:28 +03:00
parent d34579e3bb
commit b1ea179513
4 changed files with 56 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files

78
Core/display.c
View File

@@ -592,6 +592,9 @@ static void render_pixel_if_possible(GB_gameboy_t *gb)
gb->position_in_line = -16; gb->position_in_line = -16;
return; return;
} }
else {
gb->line_has_fractional_scrolling = true;
}
} }
/* Drop pixels for scrollings */ /* Drop pixels for scrollings */
@@ -787,11 +790,27 @@ static uint8_t data_for_tile_sel_glitch(GB_gameboy_t *gb, bool *should_use, bool
return gb->data_for_sel_glitch; return gb->data_for_sel_glitch;
} }
internal void GB_update_wx_glitch(GB_gameboy_t *gb)
{
if (!GB_is_cgb(gb)) return;
if (!(gb->io_registers[GB_IO_LCDC] & GB_LCDC_WIN_ENABLE) || !gb->wy_triggered) {
gb->cgb_wx_glitch = false;
return;
}
if (unlikely(gb->io_registers[GB_IO_WX] == 0)) {
// (gb->position_in_line + 16 <= 8) is (gb->position_in_line <= -8) in unsigned
gb->cgb_wx_glitch = ((uint8_t)(gb->position_in_line + 16) <= 8 ||
(gb->position_in_line == (uint8_t)-7 && gb->line_has_fractional_scrolling));
return;
}
gb->cgb_wx_glitch = (uint8_t)(gb->position_in_line + 7 + gb->window_is_being_fetched) == gb->io_registers[GB_IO_WX];
}
static void advance_fetcher_state_machine(GB_gameboy_t *gb, unsigned *cycles) static void advance_fetcher_state_machine(GB_gameboy_t *gb, unsigned *cycles)
{ {
switch ((fetcher_step_t)gb->fetcher_state) { switch ((fetcher_step_t)gb->fetcher_state) {
case GB_FETCHER_GET_TILE_T1: { case GB_FETCHER_GET_TILE_T1: {
gb->cgb_wx_glitch = GB_is_cgb(gb) && (uint8_t)(gb->position_in_line + 7 + gb->window_is_being_fetched) == gb->io_registers[GB_IO_WX]; GB_update_wx_glitch(gb);
uint16_t map = 0x1800; uint16_t map = 0x1800;
if (!(gb->io_registers[GB_IO_LCDC] & GB_LCDC_WIN_ENABLE)) { if (!(gb->io_registers[GB_IO_LCDC] & GB_LCDC_WIN_ENABLE)) {
@@ -841,8 +860,8 @@ static void advance_fetcher_state_machine(GB_gameboy_t *gb, unsigned *cycles)
break; break;
case GB_FETCHER_GET_TILE_DATA_LOWER_T1: { case GB_FETCHER_GET_TILE_DATA_LOWER_T1: {
gb->cgb_wx_glitch = GB_is_cgb(gb) && (uint8_t)(gb->position_in_line + 7 + gb->window_is_being_fetched) == gb->io_registers[GB_IO_WX]; GB_update_wx_glitch(gb);
uint8_t y_flip = 0; uint8_t y_flip = 0;
uint16_t tile_address = 0; uint16_t tile_address = 0;
uint8_t y = gb->model > GB_MODEL_CGB_C ? gb->fetcher_y : fetcher_y(gb); uint8_t y = gb->model > GB_MODEL_CGB_C ? gb->fetcher_y : fetcher_y(gb);
@@ -879,7 +898,6 @@ static void advance_fetcher_state_machine(GB_gameboy_t *gb, unsigned *cycles)
} }
if (!use_glitched) { if (!use_glitched) {
gb->current_tile_data[0] = vram_read(gb, gb->last_tile_data_address); gb->current_tile_data[0] = vram_read(gb, gb->last_tile_data_address);
} }
if (gb->last_tileset && gb->tile_sel_glitch) { if (gb->last_tileset && gb->tile_sel_glitch) {
gb->data_for_sel_glitch = vram_read(gb, gb->last_tile_data_address); gb->data_for_sel_glitch = vram_read(gb, gb->last_tile_data_address);
@@ -892,8 +910,8 @@ static void advance_fetcher_state_machine(GB_gameboy_t *gb, unsigned *cycles)
break; break;
case GB_FETCHER_GET_TILE_DATA_HIGH_T1: { case GB_FETCHER_GET_TILE_DATA_HIGH_T1: {
gb->cgb_wx_glitch = GB_is_cgb(gb) && (uint8_t)(gb->position_in_line + 7 + gb->window_is_being_fetched) == gb->io_registers[GB_IO_WX]; GB_update_wx_glitch(gb);
uint16_t tile_address = 0; uint16_t tile_address = 0;
uint8_t y = gb->model > GB_MODEL_CGB_C ? gb->fetcher_y : fetcher_y(gb); uint8_t y = gb->model > GB_MODEL_CGB_C ? gb->fetcher_y : fetcher_y(gb);
@@ -955,9 +973,7 @@ static void advance_fetcher_state_machine(GB_gameboy_t *gb, unsigned *cycles)
// fallthrough // fallthrough
default: default:
case GB_FETCHER_PUSH: { case GB_FETCHER_PUSH: {
if (gb->fetcher_state < 7) { gb->fetcher_state = GB_FETCHER_PUSH;
gb->fetcher_state++;
}
if (fifo_size(&gb->bg_fifo) > 0) break; if (fifo_size(&gb->bg_fifo) > 0) break;
if (unlikely(gb->wy_triggered && !(gb->io_registers[GB_IO_LCDC] & GB_LCDC_WIN_ENABLE) && !GB_is_cgb(gb) && !gb->disable_window_pixel_insertion_glitch)) { if (unlikely(gb->wy_triggered && !(gb->io_registers[GB_IO_LCDC] & GB_LCDC_WIN_ENABLE) && !GB_is_cgb(gb) && !gb->disable_window_pixel_insertion_glitch)) {
@@ -977,7 +993,7 @@ static void advance_fetcher_state_machine(GB_gameboy_t *gb, unsigned *cycles)
fifo_push_bg_row(&gb->bg_fifo, gb->current_tile_data[0], gb->current_tile_data[1], fifo_push_bg_row(&gb->bg_fifo, gb->current_tile_data[0], gb->current_tile_data[1],
gb->current_tile_attributes & 7, gb->current_tile_attributes & 0x80, gb->current_tile_attributes & 0x20); gb->current_tile_attributes & 7, gb->current_tile_attributes & 0x80, gb->current_tile_attributes & 0x20);
gb->fetcher_state = 0; gb->fetcher_state = GB_FETCHER_GET_TILE_T1;
} }
break; break;
} }
@@ -1509,6 +1525,7 @@ void GB_display_run(GB_gameboy_t *gb, unsigned cycles, bool force)
gb->window_y = -1; gb->window_y = -1;
gb->wy_triggered = false; gb->wy_triggered = false;
gb->position_in_line = -16; gb->position_in_line = -16;
gb->line_has_fractional_scrolling = false;
gb->ly_for_comparison = 0; gb->ly_for_comparison = 0;
gb->io_registers[GB_IO_STAT] &= ~3; gb->io_registers[GB_IO_STAT] &= ~3;
@@ -1592,6 +1609,7 @@ void GB_display_run(GB_gameboy_t *gb, unsigned cycles, bool force)
gb->delayed_glitch_hblank_interrupt = true; gb->delayed_glitch_hblank_interrupt = true;
} }
gb->position_in_line = -16; gb->position_in_line = -16;
gb->line_has_fractional_scrolling = false;
} }
} }
@@ -1693,7 +1711,7 @@ void GB_display_run(GB_gameboy_t *gb, unsigned cycles, bool force)
gb->lcd_x = 0; gb->lcd_x = 0;
/* The actual rendering cycle */ /* The actual rendering cycle */
gb->fetcher_state = 0; gb->fetcher_state = GB_FETCHER_GET_TILE_T1;
if ((gb->mode3_batching_length = mode3_batching_length(gb))) { if ((gb->mode3_batching_length = mode3_batching_length(gb))) {
GB_BATCHPOINT(gb, display, 3, gb->mode3_batching_length); GB_BATCHPOINT(gb, display, 3, gb->mode3_batching_length);
if (GB_BATCHED_CYCLES(gb, display) >= gb->mode3_batching_length) { if (GB_BATCHED_CYCLES(gb, display) >= gb->mode3_batching_length) {
@@ -1710,6 +1728,15 @@ void GB_display_run(GB_gameboy_t *gb, unsigned cycles, bool force)
goto skip_slow_mode_3; goto skip_slow_mode_3;
} }
} }
if (!gb->wx_triggered && gb->wy_triggered && (gb->io_registers[GB_IO_LCDC] & GB_LCDC_WIN_ENABLE)) {
if (gb->io_registers[GB_IO_WX] == 0) {
fifo_clear(&gb->bg_fifo);
fifo_clear(&gb->oam_fifo);
gb->wx_triggered = true;
gb->window_y++;
gb->window_tile_x = 0;
}
}
while (true) { while (true) {
/* Handle window */ /* Handle window */
/* TODO: It appears that WX checks if the window begins *next* pixel, not *this* pixel. For this reason, /* TODO: It appears that WX checks if the window begins *next* pixel, not *this* pixel. For this reason,
@@ -1720,13 +1747,7 @@ void GB_display_run(GB_gameboy_t *gb, unsigned cycles, bool force)
if (!gb->wx_triggered && gb->wy_triggered && (gb->io_registers[GB_IO_LCDC] & GB_LCDC_WIN_ENABLE)) { if (!gb->wx_triggered && gb->wy_triggered && (gb->io_registers[GB_IO_LCDC] & GB_LCDC_WIN_ENABLE)) {
bool should_activate_window = false; bool should_activate_window = false;
if (gb->io_registers[GB_IO_WX] == 0) { if (gb->io_registers[GB_IO_WX] < 166 + GB_is_cgb(gb)) {
static const uint8_t scx_to_wx0_comparisons[] = {-7, -1, -2, -3, -4, -5, -6, -6};
if (gb->position_in_line == scx_to_wx0_comparisons[gb->io_registers[GB_IO_SCX] & 7]) {
should_activate_window = true;
}
}
else if (gb->io_registers[GB_IO_WX] < 166 + GB_is_cgb(gb)) {
if (gb->io_registers[GB_IO_WX] == (uint8_t) (gb->position_in_line + 7)) { if (gb->io_registers[GB_IO_WX] == (uint8_t) (gb->position_in_line + 7)) {
should_activate_window = true; should_activate_window = true;
} }
@@ -1752,7 +1773,7 @@ void GB_display_run(GB_gameboy_t *gb, unsigned cycles, bool force)
GB_SLEEP(gb, display, 42, 1); GB_SLEEP(gb, display, 42, 1);
} }
gb->wx_triggered = true; gb->wx_triggered = true;
gb->fetcher_state = 0; gb->fetcher_state = GB_FETCHER_GET_TILE_T1;
gb->window_is_being_fetched = true; gb->window_is_being_fetched = true;
} }
else if (!GB_is_cgb(gb) && gb->io_registers[GB_IO_WX] == 166 && gb->io_registers[GB_IO_WX] == (uint8_t) (gb->position_in_line + 7)) { else if (!GB_is_cgb(gb) && gb->io_registers[GB_IO_WX] == 166 && gb->io_registers[GB_IO_WX] == (uint8_t) (gb->position_in_line + 7)) {
@@ -1762,7 +1783,7 @@ void GB_display_run(GB_gameboy_t *gb, unsigned cycles, bool force)
/* TODO: What happens when WX=0?*/ /* TODO: What happens when WX=0?*/
if (!GB_is_cgb(gb) && gb->wx_triggered && !gb->window_is_being_fetched && if (!GB_is_cgb(gb) && gb->wx_triggered && !gb->window_is_being_fetched &&
gb->fetcher_state == 0 && gb->io_registers[GB_IO_WX] == (uint8_t) (gb->position_in_line + 7) && gb->bg_fifo.size == 8) { gb->fetcher_state == GB_FETCHER_GET_TILE_T1 && gb->io_registers[GB_IO_WX] == (uint8_t) (gb->position_in_line + 7) && gb->bg_fifo.size == 8) {
// Insert a pixel right at the FIFO's end // Insert a pixel right at the FIFO's end
gb->insert_bg_pixel = true; gb->insert_bg_pixel = true;
} }
@@ -1859,19 +1880,26 @@ abort_fetching_object:
render_pixel_if_possible(gb); render_pixel_if_possible(gb);
advance_fetcher_state_machine(gb, &cycles); advance_fetcher_state_machine(gb, &cycles);
if (gb->position_in_line == 160) break; if (gb->position_in_line == 160) break;
gb->cycles_for_line++; gb->cycles_for_line++;
GB_SLEEP(gb, display, 21, 1); GB_SLEEP(gb, display, 21, 1);
} }
skip_slow_mode_3: skip_slow_mode_3:
gb->position_in_line = -16; gb->position_in_line = -16;
gb->line_has_fractional_scrolling = false;
/* TODO: This seems incorrect (glitches Tesserae), verify further */ /* TODO: Commented code seems incorrect (glitches Tesserae), verify further */
/*
if (gb->fetcher_state == 4 || gb->fetcher_state == 5) { if (gb->fetcher_state == GB_FETCHER_GET_TILE_DATA_HIGH_T1 ||
gb->data_for_sel_glitch = gb->current_tile_data[0]; gb->fetcher_state == GB_FETCHER_GET_TILE_DATA_HIGH_T2) {
// Make sure current_tile_data[1] holds the last tile data byte read
gb->current_tile_data[1] = gb->current_tile_data[0];
//gb->data_for_sel_glitch = gb->current_tile_data[0];
} }
/*
else { else {
gb->data_for_sel_glitch = gb->current_tile_data[1]; gb->data_for_sel_glitch = gb->current_tile_data[1];
} }

1
Core/display.h
View File

@@ -17,6 +17,7 @@ internal void GB_palette_changed(GB_gameboy_t *gb, bool background_palette, uint
internal void GB_STAT_update(GB_gameboy_t *gb); internal void GB_STAT_update(GB_gameboy_t *gb);
internal void GB_lcd_off(GB_gameboy_t *gb); internal void GB_lcd_off(GB_gameboy_t *gb);
internal void GB_display_vblank(GB_gameboy_t *gb, GB_vblank_type_t type); internal void GB_display_vblank(GB_gameboy_t *gb, GB_vblank_type_t type);
internal void GB_update_wx_glitch(GB_gameboy_t *gb);
#define GB_display_sync(gb) GB_display_run(gb, 0, true) #define GB_display_sync(gb) GB_display_run(gb, 0, true)
enum { enum {

1
Core/gb.h
View File

@@ -649,6 +649,7 @@ struct GB_gameboy_internal_s {
uint32_t frame_parity_ticks; uint32_t frame_parity_ticks;
bool last_tileset; bool last_tileset;
bool cgb_wx_glitch; bool cgb_wx_glitch;
bool line_has_fractional_scrolling;
) )
GB_SECTION(accessory, GB_SECTION(accessory,

2
Core/memory.c
View File

@@ -1399,7 +1399,7 @@ static void write_high_memory(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
gb->wy_triggered = true; gb->wy_triggered = true;
} }
case GB_IO_WX: case GB_IO_WX:
gb->cgb_wx_glitch = GB_is_cgb(gb) && (uint8_t)(gb->position_in_line + 7 + gb->window_is_being_fetched) == value; GB_update_wx_glitch(gb);
case GB_IO_IF: case GB_IO_IF:
case GB_IO_SCX: case GB_IO_SCX:
case GB_IO_SCY: case GB_IO_SCY: