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Render the first line 0, as required for SGB emulation

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This commit is contained in:
Lior Halphon 2019-02-16 04:19:16 +02:00
parent 9d0aadb83f
commit 0b03b61564
2 changed files with 46 additions and 68 deletions
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2
Core/debugger.c
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@ -1525,7 +1525,7 @@ static bool lcd(GB_gameboy_t *gb, char *arguments, char *modifiers, const debugg
GB_log(gb, "Reading OAM data (%d/40)\n", gb->display_state == 8? gb->oam_search_index : 0);
}
else if (gb->display_state <= 3 || gb->display_state == 24 || gb->display_state == 31) {
GB_log(gb, "Glitched line 0 (%d cycles to next event)\n", -gb->display_cycles / 2);
GB_log(gb, "Glitched line 0 OAM mode (%d cycles to next event)\n", -gb->display_cycles / 2);
}
else if (gb->mode_for_interrupt == 3) {
signed pixel = gb->position_in_line > 160? (int8_t) gb->position_in_line : gb->position_in_line;

108
Core/display.c
View File

@ -95,12 +95,8 @@ static void fifo_overlay_object_row(GB_fifo_t *fifo, uint8_t lower, uint8_t uppe
Mode 1 is VBlank
*/
/* Todo: Clean up the glitched line 0 and get rid of these defines */
#define MODE2_LENGTH (80)
#define MODE3_LENGTH (172)
#define MODE0_LENGTH (204)
#define LINE_LENGTH (MODE2_LENGTH + MODE3_LENGTH + MODE0_LENGTH) // = 456
#define LINE_LENGTH (456)
#define LINES (144)
#define WIDTH (160)
#define FRAME_LENGTH (LCDC_PERIOD)
@ -564,9 +560,9 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
GB_STATE_MACHINE(gb, display, cycles, 2) {
GB_STATE(gb, display, 1);
GB_STATE(gb, display, 2);
GB_STATE(gb, display, 3);
GB_STATE(gb, display, 4);
GB_STATE(gb, display, 5);
// GB_STATE(gb, display, 3);
// GB_STATE(gb, display, 4);
// GB_STATE(gb, display, 5);
GB_STATE(gb, display, 6);
GB_STATE(gb, display, 7);
GB_STATE(gb, display, 8);
@ -584,19 +580,21 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
GB_STATE(gb, display, 21);
GB_STATE(gb, display, 22);
GB_STATE(gb, display, 23);
GB_STATE(gb, display, 24);
// GB_STATE(gb, display, 24);
GB_STATE(gb, display, 25);
GB_STATE(gb, display, 26);
GB_STATE(gb, display, 27);
GB_STATE(gb, display, 28);
GB_STATE(gb, display, 29);
GB_STATE(gb, display, 30);
GB_STATE(gb, display, 31);
// GB_STATE(gb, display, 31);
GB_STATE(gb, display, 32);
GB_STATE(gb, display, 33);
GB_STATE(gb, display, 34);
GB_STATE(gb, display, 35);
GB_STATE(gb, display, 36);
GB_STATE(gb, display, 37);
GB_STATE(gb, display, 38);
}
@ -612,9 +610,7 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
GB_SLEEP(gb, display, 23, 1);
}
/* Todo: Merge this with the normal line routine */
/* Todo: Needs actual rendering, affects SGB emulation */
/* Handle the very first line 0 */
/* Handle mode 2 on the very first line 0 */
gb->current_line = 0;
gb->ly_for_comparison = 0;
gb->io_registers[GB_IO_STAT] &= ~3;
@ -633,56 +629,33 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
GB_STAT_update(gb);
GB_SLEEP(gb, display, 34, 2);
gb->n_visible_objs = 0;
gb->cycles_for_line += 8; // Mode 0 is shorter on the first line 0, so we augment cycles_for_line by 8 extra cycles.
gb->io_registers[GB_IO_STAT] &= ~3;
gb->io_registers[GB_IO_STAT] |= 3;
gb->mode_for_interrupt = 3;
gb->oam_read_blocked = true;
gb->vram_read_blocked = !GB_is_cgb(gb) || gb->cgb_double_speed;
gb->vram_write_blocked = !GB_is_cgb(gb) || gb->cgb_double_speed;
gb->cgb_palettes_blocked = !GB_is_cgb(gb);
GB_STAT_update(gb);
gb->cycles_for_line += 2;
GB_SLEEP(gb, display, 24, 2);
gb->oam_write_blocked = true;
gb->oam_read_blocked = true;
gb->vram_read_blocked = gb->cgb_double_speed;
gb->vram_write_blocked = gb->cgb_double_speed;
if (!GB_is_cgb(gb)) {
gb->vram_read_blocked = true;
gb->vram_write_blocked = true;
gb->cgb_palettes_blocked = true;
gb->current_lcd_line++; // TODO: Verify timing
if (gb->current_lcd_line == LINES) {
display_vblank(gb);
}
/* TODO: How does the window affect this line? */
gb->cycles_for_line += MODE3_LENGTH + (gb->io_registers[GB_IO_SCX] & 7) - 2;
GB_SLEEP(gb, display, 3, MODE3_LENGTH + (gb->io_registers[GB_IO_SCX] & 7) - 2);
if (!gb->cgb_double_speed) {
gb->io_registers[GB_IO_STAT] &= ~3;
gb->mode_for_interrupt = 0;
gb->oam_read_blocked = false;
gb->vram_read_blocked = false;
gb->oam_write_blocked = false;
gb->vram_write_blocked = false;
}
gb->cycles_for_line += 1;
GB_SLEEP(gb, display, 4, 1);
gb->io_registers[GB_IO_STAT] &= ~3;
gb->mode_for_interrupt = 0;
gb->oam_read_blocked = false;
gb->vram_read_blocked = false;
gb->oam_write_blocked = false;
gb->vram_write_blocked = false;
gb->cycles_for_line += 2;
GB_SLEEP(gb, display, 31, 2);
gb->cgb_palettes_blocked = false;
GB_SLEEP(gb, display, 37, 2);
gb->cgb_palettes_blocked = true;
gb->cycles_for_line += 2;
GB_SLEEP(gb, display, 38, 2);
gb->vram_read_blocked = true;
gb->vram_write_blocked = true;
goto mode_3_start;
GB_STAT_update(gb);
/* Mode 0 is shorter in the very first line */
GB_SLEEP(gb, display, 5, LINE_LENGTH - gb->cycles_for_line - 8);
gb->mode_for_interrupt = 2;
gb->current_line = 1;
while (true) {
/* Lines 0 - 143 */
for (; gb->current_line < LINES; gb->current_line++) {
@ -738,6 +711,8 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
GB_STAT_update(gb);
}
}
gb->cycles_for_line = MODE2_LENGTH + 4;
gb->accessed_oam_row = -1;
gb->io_registers[GB_IO_STAT] &= ~3;
gb->io_registers[GB_IO_STAT] |= 3;
@ -746,9 +721,23 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
gb->vram_write_blocked = true;
gb->cgb_palettes_blocked = false;
gb->oam_write_blocked = true;
gb->oam_read_blocked = true;
GB_STAT_update(gb);
gb->cycles_for_line = MODE2_LENGTH + 4;
uint8_t idle_cycles = 3;
if (GB_is_cgb(gb) && gb->model <= GB_MODEL_CGB_C) {
idle_cycles = 2;
}
gb->cycles_for_line += idle_cycles;
GB_SLEEP(gb, display, 10, idle_cycles);
gb->cgb_palettes_blocked = true;
gb->cycles_for_line += 2;
GB_SLEEP(gb, display, 32, 2);
mode_3_start:
fifo_clear(&gb->bg_fifo);
fifo_clear(&gb->oam_fifo);
/* Fill the FIFO with 8 pixels of "junk", it's going to be dropped anyway. */
@ -762,17 +751,6 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
gb->fetcher_x = ((gb->io_registers[GB_IO_SCX]) / 8) & 0x1f;
gb->extra_penalty_for_sprite_at_0 = (gb->io_registers[GB_IO_SCX] & 7);
uint8_t idle_cycles = 3;
if (GB_is_cgb(gb) && gb->model <= GB_MODEL_CGB_C) {
idle_cycles = 2;
}
gb->cycles_for_line += idle_cycles;
GB_SLEEP(gb, display, 10, idle_cycles);
gb->cgb_palettes_blocked = true;
gb->cycles_for_line += 2;
GB_SLEEP(gb, display, 32, 2);
/* The actual rendering cycle */
gb->fetcher_state = 0;