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Basic window implementation

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This commit is contained in:
Lior Halphon 2020-02-23 23:16:45 +02:00
parent 2be58439bf
commit c0ba898ef2
2 changed files with 73 additions and 11 deletions
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78
Core/display.c
View File

@ -530,7 +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->io_registers[GB_IO_SCY];
return gb->wx_triggered? gb->window_y : gb->current_line + gb->io_registers[GB_IO_SCY];
}
static void advance_fetcher_state_machine(GB_gameboy_t *gb)
@ -539,6 +539,7 @@ static void advance_fetcher_state_machine(GB_gameboy_t *gb)
GB_FETCHER_GET_TILE,
GB_FETCHER_GET_TILE_DATA_LOWER,
GB_FETCHER_GET_TILE_DATA_HIGH,
GB_ADVANCE_TILES,
GB_FETCHER_PUSH,
GB_FETCHER_SLEEP,
} fetcher_step_t;
@ -550,7 +551,7 @@ static void advance_fetcher_state_machine(GB_gameboy_t *gb)
GB_FETCHER_GET_TILE_DATA_LOWER,
GB_FETCHER_SLEEP,
GB_FETCHER_GET_TILE_DATA_HIGH,
GB_FETCHER_SLEEP,
GB_ADVANCE_TILES,
GB_FETCHER_PUSH,
};
@ -558,17 +559,27 @@ static void advance_fetcher_state_machine(GB_gameboy_t *gb)
case GB_FETCHER_GET_TILE: {
uint16_t map = 0x1800;
if (!(gb->io_registers[GB_IO_LCDC] & 0x20)) {
gb->wx_triggered = false;
}
/* 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->wx_triggered) {
map = 0x1C00;
}
/* else if (gb->io_registers[GB_IO_LCDC] & 0x40 && gb->in_window) {
else if (gb->io_registers[GB_IO_LCDC] & 0x40 && gb->wx_triggered) {
map = 0x1C00;
} */
}
/* Todo: Verified for DMG (Tested: SGB2), CGB timing is wrong. */
uint8_t y = fetcher_y(gb);
uint8_t x = ((gb->io_registers[GB_IO_SCX] / 8) + gb->fetcher_x) & 0x1F;
uint8_t x = 0;
if (gb->wx_triggered) {
x = gb->window_tile_x;
}
else {
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;
@ -585,8 +596,6 @@ static void advance_fetcher_state_machine(GB_gameboy_t *gb)
gb->current_tile_attributes = 0xFF;
}
}
gb->fetcher_x++;
gb->fetcher_x &= 0x1f;
}
gb->fetcher_state++;
break;
@ -648,6 +657,19 @@ static void advance_fetcher_state_machine(GB_gameboy_t *gb)
gb->fetcher_state++;
break;
case GB_ADVANCE_TILES: {
if (gb->wx_triggered) {
gb->window_tile_x++;
gb->window_tile_x &= 0x1f;
}
else {
gb->fetcher_x++;
gb->fetcher_x &= 0x1f;
}
gb->fetcher_state++;
}
case GB_FETCHER_PUSH: {
if (fifo_size(&gb->bg_fifo) > 0) break;
fifo_push_bg_row(&gb->bg_fifo, gb->current_tile_data[0], gb->current_tile_data[1],
@ -767,6 +789,15 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
/* Handle mode 2 on the very first line 0 */
gb->current_line = 0;
gb->window_y = -1;
/* Todo: verify timings */
if (gb->io_registers[GB_IO_WY] == 0) {
gb->wy_triggered = true;
}
else {
gb->wy_triggered = false;
}
gb->ly_for_comparison = 0;
gb->io_registers[GB_IO_STAT] &= ~3;
gb->mode_for_interrupt = -1;
@ -813,7 +844,16 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
while (true) {
/* Lines 0 - 143 */
gb->window_y = -1;
for (; gb->current_line < LINES; gb->current_line++) {
gb->wx_triggered = false;
/* Todo: verify timings */
if ((gb->io_registers[GB_IO_WY] == gb->current_line ||
(gb->current_line != 0 && gb->io_registers[GB_IO_WY] == gb->current_line - 1))) {
gb->wy_triggered = true;
}
gb->window_tile_x = 0;
gb->oam_write_blocked = GB_is_cgb(gb) && !gb->cgb_double_speed;
gb->accessed_oam_row = 0;
@ -994,7 +1034,18 @@ abort_fetching_object:
gb->during_object_fetch = false;
/* Handle window */
/* TBD */
/* Todo: verify timings */
if (!gb->wx_triggered && gb->wy_triggered && (gb->io_registers[GB_IO_LCDC] & 0x20)) {
if (gb->io_registers[GB_IO_WX] == gb->position_in_line + 7 ||
gb->io_registers[GB_IO_WX] == gb->position_in_line + 6) {
gb->wx_triggered = true;
gb->window_y++;
fifo_clear(&gb->bg_fifo);
gb->bg_fifo_paused = true;
gb->oam_fifo_paused = true;
gb->fetcher_state = 0;
}
}
render_pixel_if_possible(gb);
advance_fetcher_state_machine(gb);
@ -1130,6 +1181,15 @@ abort_fetching_object:
gb->current_line = 0;
/* Todo: verify timings */
if ((gb->io_registers[GB_IO_LCDC] & 0x20) &&
(gb->io_registers[GB_IO_WY] == 0)) {
gb->wy_triggered = true;
}
else {
gb->wy_triggered = false;
}
// TODO: not the correct timing
gb->current_lcd_line = 0;
if (gb->icd_vreset_callback) {

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;
GB_PADDING(uint8_t,wy_diff);
uint8_t window_y;
/* 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/ */
@ -502,7 +502,7 @@ struct GB_gameboy_internal_s {
uint8_t fetcher_state;
bool bg_fifo_paused;
bool oam_fifo_paused;
GB_PADDING(bool, in_window);
bool wx_triggered;
uint8_t visible_objs[10];
uint8_t obj_comparators[10];
uint8_t n_visible_objs;
@ -521,6 +521,8 @@ struct GB_gameboy_internal_s {
bool object_fetch_aborted;
bool during_object_fetch;
uint16_t object_low_line_address;
bool wy_triggered;
uint8_t window_tile_x;
);
/* Unsaved data. This includes all pointers, as well as everything that shouldn't be on a save state */