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Starting over – removing all window related code

This commit is contained in:
Lior Halphon 2020-02-23 00:38:47 +02:00
parent 83ea4edce2
commit 2be58439bf
4 changed files with 10 additions and 70 deletions
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68
Core/display.c
View File

@ -111,16 +111,6 @@ typedef struct __attribute__((packed)) {
uint8_t flags;
} GB_object_t;
static bool window_enabled(GB_gameboy_t *gb)
{
if ((gb->io_registers[GB_IO_LCDC] & 0x1) == 0) {
if (!gb->cgb_mode) {
return false;
}
}
return (gb->io_registers[GB_IO_LCDC] & 0x20) && gb->io_registers[GB_IO_WX] < 167;
}
static void display_vblank(GB_gameboy_t *gb)
{
gb->vblank_just_occured = true;
@ -388,9 +378,6 @@ void GB_lcd_off(GB_gameboy_t *gb)
gb->vram_write_blocked = false;
gb->cgb_palettes_blocked = false;
/* Reset window rendering state */
gb->wy_diff = 0;
gb->window_disabled_while_active = false;
gb->current_line = 0;
gb->ly_for_comparison = 0;
@ -543,7 +530,7 @@ static void render_pixel_if_possible(GB_gameboy_t *gb)
static inline uint8_t fetcher_y(GB_gameboy_t *gb)
{
return gb->current_line + (gb->in_window? - gb->io_registers[GB_IO_WY] - gb->wy_diff : gb->io_registers[GB_IO_SCY]);
return gb->current_line + gb->io_registers[GB_IO_SCY];
}
static void advance_fetcher_state_machine(GB_gameboy_t *gb)
@ -572,17 +559,16 @@ static void advance_fetcher_state_machine(GB_gameboy_t *gb)
uint16_t map = 0x1800;
/* Todo: Verified for DMG (Tested: SGB2), CGB timing is wrong. */
if (gb->io_registers[GB_IO_LCDC] & 0x08 && !gb->in_window) {
if (gb->io_registers[GB_IO_LCDC] & 0x08 /* && !gb->in_window */) {
map = 0x1C00;
}
else if (gb->io_registers[GB_IO_LCDC] & 0x40 && gb->in_window) {
/* else if (gb->io_registers[GB_IO_LCDC] & 0x40 && gb->in_window) {
map = 0x1C00;
}
} */
/* Todo: Verified for DMG (Tested: SGB2), CGB timing is wrong. */
uint8_t y = fetcher_y(gb);
uint8_t x = gb->in_window? gb->fetcher_x :
(((gb->io_registers[GB_IO_SCX] / 8) + gb->fetcher_x) & 0x1F);
uint8_t x = ((gb->io_registers[GB_IO_SCX] / 8) + gb->fetcher_x) & 0x1F;
if (gb->model > GB_MODEL_CGB_C) {
/* This value is cached on the CGB-D and newer, so it cannot be used to mix tiles together */
gb->fetcher_y = y;
@ -922,7 +908,6 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
gb->fetcher_state = 0;
gb->bg_fifo_paused = false;
gb->oam_fifo_paused = false;
gb->in_window = false;
while (true) {
/* Handle objects */
/* When the sprite enabled bit is off, this proccess is skipped entirely on the DMG, but not on the CGB.
@ -1009,17 +994,7 @@ abort_fetching_object:
gb->during_object_fetch = false;
/* Handle window */
/* Todo: Timing (Including penalty and access timings) not verified by test ROM */
if (!gb->in_window && window_enabled(gb) &&
gb->current_line >= gb->io_registers[GB_IO_WY] + gb->wy_diff &&
(uint8_t)(gb->position_in_line + 7) == gb->io_registers[GB_IO_WX]) {
gb->in_window = true;
fifo_clear(&gb->bg_fifo);
gb->bg_fifo_paused = true;
gb->oam_fifo_paused = true;
gb->fetcher_x = 0;
gb->fetcher_state = 0;
}
/* TBD */
render_pixel_if_possible(gb);
advance_fetcher_state_machine(gb);
@ -1154,9 +1129,6 @@ abort_fetching_object:
GB_SLEEP(gb, display, 17, LINE_LENGTH - 24);
/* Reset window rendering state */
gb->wy_diff = 0;
gb->window_disabled_while_active = false;
gb->current_line = 0;
// TODO: not the correct timing
gb->current_lcd_line = 0;
@ -1343,31 +1315,3 @@ uint8_t GB_get_oam_info(GB_gameboy_t *gb, GB_oam_info_t *dest, uint8_t *sprite_h
}
return count;
}
/* Called when a write might enable or disable the window */
void GB_window_related_write(GB_gameboy_t *gb, uint8_t addr, uint8_t value)
{
bool before = window_enabled(gb);
gb->io_registers[addr] = value;
bool after = window_enabled(gb);
if (before != after && gb->current_line < LINES) {
/* Window was disabled or enabled outside of vblank */
if (gb->current_line >= gb->io_registers[GB_IO_WY]) {
if (after) {
if (!gb->window_disabled_while_active) {
/* Window was turned on for the first time this frame while LY > WY,
should start window in the next line */
gb->wy_diff = gb->current_line + 1 - gb->io_registers[GB_IO_WY];
}
else {
gb->wy_diff += gb->current_line;
}
}
else {
gb->wy_diff -= gb->current_line;
gb->window_disabled_while_active = true;
}
}
}
}

1
Core/display.h
View File

@ -8,7 +8,6 @@
#ifdef GB_INTERNAL
void GB_display_run(GB_gameboy_t *gb, uint8_t cycles);
void GB_palette_changed(GB_gameboy_t *gb, bool background_palette, uint8_t index);
void GB_window_related_write(GB_gameboy_t *gb, uint8_t addr, uint8_t value);
void GB_STAT_update(GB_gameboy_t *gb);
void GB_lcd_off(GB_gameboy_t *gb);

6
Core/gb.h
View File

@ -472,7 +472,7 @@ struct GB_gameboy_internal_s {
uint8_t position_in_line;
bool stat_interrupt_line;
uint8_t effective_scx;
uint8_t wy_diff;
GB_PADDING(uint8_t,wy_diff);
/* The LCDC will skip the first frame it renders after turning it on.
On the CGB, a frame is not skipped if the previous frame was skipped as well.
See https://www.reddit.com/r/EmuDev/comments/6exyxu/ */
@ -489,7 +489,7 @@ struct GB_gameboy_internal_s {
bool vram_read_blocked;
bool oam_write_blocked;
bool vram_write_blocked;
bool window_disabled_while_active;
GB_PADDING(bool, window_disabled_while_active);
uint8_t current_line;
uint16_t ly_for_comparison;
GB_fifo_t bg_fifo, oam_fifo;
@ -502,7 +502,7 @@ struct GB_gameboy_internal_s {
uint8_t fetcher_state;
bool bg_fifo_paused;
bool oam_fifo_paused;
bool in_window;
GB_PADDING(bool, in_window);
uint8_t visible_objs[10];
uint8_t obj_comparators[10];
uint8_t n_visible_objs;

5
Core/memory.c
View File

@ -646,8 +646,6 @@ static void write_high_memory(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
/* Hardware registers */
switch (addr & 0xFF) {
case GB_IO_WX:
GB_window_related_write(gb, addr & 0xFF, value);
break;
case GB_IO_IF:
case GB_IO_SCX:
case GB_IO_SCY:
@ -740,8 +738,7 @@ static void write_high_memory(GB_gameboy_t *gb, uint16_t addr, uint8_t value)
GB_timing_sync(gb);
GB_lcd_off(gb);
}
/* Writing to LCDC might enable to disable the window, so we write it via GB_window_related_write */
GB_window_related_write(gb, addr & 0xFF, value);
gb->io_registers[GB_IO_LCDC] = value;
return;
case GB_IO_STAT: