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The OAM interrupt is internally implemented differently from the other 3. Fixed the stat_write_if tests, relates to #54

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This commit is contained in:
Lior Halphon 2018-04-01 21:45:56 +03:00
parent 69a625af97
commit ec64c041ab
2 changed files with 32 additions and 18 deletions
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47
Core/display.c
View File

@ -230,12 +230,20 @@ void GB_set_color_correction_mode(GB_gameboy_t *gb, GB_color_correction_mode_t m
*/
static void trigger_oam_interrupt(GB_gameboy_t *gb)
{
if (!gb->stat_interrupt_line && gb->oam_interrupt_line) {
gb->io_registers[GB_IO_IF] |= 2;
gb->stat_interrupt_line = true;
}
}
void GB_STAT_update(GB_gameboy_t *gb)
{
if (!(gb->io_registers[GB_IO_LCDC] & 0x80)) return;
bool previous_interrupt_line = gb->stat_interrupt_line;
gb->stat_interrupt_line = false;
bool previous_interrupt_line = gb->stat_interrupt_line | gb->oam_interrupt_line;
gb->stat_interrupt_line = gb->oam_interrupt_line;
/* Set LY=LYC bit */
if (gb->ly_for_comparison == gb->io_registers[GB_IO_LYC]) {
gb->io_registers[GB_IO_STAT] |= 4;
@ -247,7 +255,9 @@ void GB_STAT_update(GB_gameboy_t *gb)
switch (gb->io_registers[GB_IO_STAT] & 3) {
case 0: gb->stat_interrupt_line = (gb->io_registers[GB_IO_STAT] & 8) && !gb->is_first_line_mode2; break;
case 1: gb->stat_interrupt_line = gb->io_registers[GB_IO_STAT] & 0x10; break;
case 2: gb->stat_interrupt_line = gb->io_registers[GB_IO_STAT] & 0x20; break;
/* The OAM interrupt is handled differently, it reads the writable flags from STAT less frequenctly,
and is not based on the mode bits of STAT. */
// case 2: gb->stat_interrupt_line = gb->io_registers[GB_IO_STAT] & 0x20; break;
}
/* User requested a LY=LYC interrupt and the LY=LYC bit is on */
@ -255,7 +265,7 @@ void GB_STAT_update(GB_gameboy_t *gb)
gb->stat_interrupt_line = true;
}
if (gb->stat_interrupt_line && ! previous_interrupt_line) {
if (gb->stat_interrupt_line && !previous_interrupt_line) {
gb->io_registers[GB_IO_IF] |= 2;
}
}
@ -494,9 +504,9 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
/* The OAM STAT interrupt occurs 1 T-cycle before STAT actually changes, except on line 0.
PPU glitch? (Todo: and in double speed mode?) */
if (gb->current_line != 0 && !gb->cgb_double_speed) {
gb->io_registers[GB_IO_STAT] &= ~3;
gb->io_registers[GB_IO_STAT] |= 2;
gb->oam_interrupt_line = gb->io_registers[GB_IO_STAT] & 0x20;
}
trigger_oam_interrupt(gb);
GB_STAT_update(gb);
if (gb->current_line != 0 || !gb->is_cgb) {
gb->io_registers[GB_IO_STAT] &= ~3;
@ -508,6 +518,10 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
gb->io_registers[GB_IO_STAT] |= 2;
gb->oam_write_blocked = true;
gb->ly_for_comparison = gb->current_line;
if (gb->current_line == 0 || gb->cgb_double_speed) {
gb->oam_interrupt_line = gb->io_registers[GB_IO_STAT] & 0x20;
}
trigger_oam_interrupt(gb);
GB_STAT_update(gb);
gb->n_visible_objs = 0;
@ -529,12 +543,13 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
}
}
gb->accessed_oam_row = -1;
gb->io_registers[GB_IO_STAT] &= ~3;
gb->io_registers[GB_IO_STAT] |= 3;
gb->vram_read_blocked = true;
gb->vram_write_blocked = true;
gb->oam_write_blocked = true;
gb->oam_interrupt_line = false;
trigger_oam_interrupt(gb);
GB_STAT_update(gb);
gb->cycles_for_line = MODE2_LENGTH + 4;
@ -730,22 +745,20 @@ void GB_display_run(GB_gameboy_t *gb, uint8_t cycles)
gb->ly_for_comparison = -1;
}
if (gb->current_line == LINES) {
gb->io_registers[GB_IO_STAT] &= ~3;
gb->io_registers[GB_IO_STAT] |= 2;
GB_STAT_update(gb);
gb->io_registers[GB_IO_STAT] &= ~3;
}
else {
GB_STAT_update(gb);
gb->oam_interrupt_line = gb->io_registers[GB_IO_STAT] & 0x20;
trigger_oam_interrupt(gb);
}
GB_STAT_update(gb);
gb->oam_interrupt_line = false;
GB_SLEEP(gb, display, 12, 4);
gb->ly_for_comparison = gb->current_line;
if (gb->current_line == LINES) {
/* Entering VBlank state triggers the OAM interrupt. In CGB, it happens 4 cycles earlier */
gb->io_registers[GB_IO_STAT] &= ~3;
gb->io_registers[GB_IO_STAT] |= 2;
/* Entering VBlank state triggers the OAM interrupt*/
gb->oam_interrupt_line = gb->io_registers[GB_IO_STAT] & 0x20;
trigger_oam_interrupt(gb);
GB_STAT_update(gb);
gb->oam_interrupt_line = false;
gb->io_registers[GB_IO_STAT] &= ~3;
gb->io_registers[GB_IO_STAT] |= 1;

1
Core/gb.h
View File

@ -430,6 +430,7 @@ struct GB_gameboy_internal_s {
uint8_t accessed_oam_row;
uint8_t extra_penalty_for_sprite_at_0;
bool is_first_line_mode2;
bool oam_interrupt_line;
);
/* Unsaved data. This includes all pointers, as well as everything that shouldn't be on a save state */